Whether you are an manufacturer or consumer, you can never ignore the existence of plastics material. For our daily use product or industrial use products, plastic is an essential material, we should pay a great attention to.
Whether for automobile, IT products, appliance, or even our cloth, we can see plastic to be widely used. Below are 20 different basics plastics we often or sometimes used.
- ABS (acrylonitrile-butadiene-styrene copolymer)
- Nylon 6 (PA6 Polyamide 6)
- Nylon 12 (PA12 polyamide 12)
- Nylon 66 (PA66 polyamide 66)
- PBT (Polybutylene Terephthalate)
- PC (polycarbonate)
- PC/ABS Alloy (polycarbonate and acrylonitrile-butadiene-styrene copolymers)
- PC/PBT Alloy (Polycarbonate and Polybutylene terephthalate Alloy)
- HDPE (High Density Polyethylene)
- LDPE (Low density polyethylene)
- PEI (Polyethylenimine)
- PET (Polyethylene terephthalate)
- PETG (Ethylene glycol modified – polyethylene terephthalate)
- PMMA (Polymethyl methacrylate)
- POM (Polyoxymethylene)
- PP (Polypropylene)
- PPE (Polypropylene)
- PS (Polystyrene)
- PVC (polyvinyl chloride)
- SA (Styrene-acrylonitrile copolymer)
1. ABS acrylonitrile-butadiene-styrene copolymer
ABS is synthesized from three chemical monomers, acrylonitrile, butadiene and styrene. Each monomer has different characteristics. Acrylonitrile has high strength, thermal stability and chemical stability. Butadiene has toughness and impact resistance. Styrene has easy processing, high finish and high strength.
Morphologically, ABS is a non-crystalline material. Polymerization of the three monomers produces a terpolymer with two phases, a continuous styrene-acrylonitrile phase and a dispersed polybutadiene rubber phase. The properties of ABS mainly depend on the ratio of the three monomers and the molecular structure in the two phases.
This allows great flexibility in product design, and thus produces hundreds of different qualities of ABS materials on the market. These different qualities of material offer different properties, such as medium to high impact resistance, low to high finish, and high temperature distortion characteristics, among others.
ABS material has super easy processability, appearance characteristics, low creep and excellent dimensional stability and high impact strength.
| Performance Classification | Specific Performance | Description |
|---|---|---|
| ABS Physical Properties | Appearance | Opaque, ivory-colored granules. Products can be colored in various colors and have high glossiness. |
| Relative Density | Approximately 1.05. | |
| Water Absorption | Low, with a water absorption rate of no more than 1% after immersion in water at room temperature for one year. | |
| Solubility | Insoluble in water, resistant to water, inorganic salts, alkalis, and acids, but soluble in ketones, aldehydes, and chlorinated hydrocarbons. | |
| Mechanical Properties | Impact Strength | Excellent, and can be used at extremely low temperatures. |
| Wear Resistance | Good. | |
| Dimensional Stability | Good. | |
| Oil Resistance | Good, and can be used for bearings under medium loads and rotational speeds. | |
| Flexural Strength | Poor among plastics. | |
| Compressive Strength | Poor among plastics. | |
| ABS Thermal Properties | Heat Deflection Temperature | 93 – 118℃, and the product can be further improved by about 10℃ after annealing treatment. |
| Operating Temperature Range | -40 – 100℃. | |
| Melting Temperature | 217 – 237℃. | |
| Thermal Decomposition Temperature | Above 250℃. | |
| Electrical Properties | Electrical Insulation | Good, and is hardly affected by temperature, humidity, and frequency, so it can be used in most environments. |
| Chemical Properties | Chemical Corrosion Resistance | Resistant to water, inorganic salts, alkalis, and acids, but may be subject to stress cracking when exposed to glacial acetic acid, vegetable oils, etc. |
| Other Properties | Oxygen Index | 18 – 20, belonging to a flammable polymer. The flame is yellow with black smoke, and emits a special cinnamon smell. |
| Processing Performance | Excellent, and can be processed by common processing methods. The melt fluidity is better than that of PVC and PC, but worse than that of PE, PA, and PS, similar to that of POM and HIPS. The flow characteristics belong to non-Newtonian fluids. |
2. PA6 Polyamide 6 or Nylon 6
The chemical and physical properties of PA6 are very similar to PA66, however, it has a lower melting point and a wide range of process temperatures. Its impact resistance and solvent resistance are better than PA66, but it is also more hygroscopic. Because many quality characteristics of plastic parts are affected by hygroscopicity, this should be fully considered when designing products using PA6.
In order to improve the mechanical properties of PA6, various modifiers are often added. Glass is the most common additive, and sometimes synthetic rubber, such as EPDM and SBR, is added to improve impact resistance. For products without additives, the shrinkage of PA6 is between 1% and 1.5%. Addition of glass fiber additives reduces shrinkage to 0.3% (but slightly higher perpendicular to process).
The shrinkage of molded assemblies is mainly affected by the crystallinity and hygroscopicity of the material. The actual shrinkage rate is also a function of the plastic part design, wall thickness and other process parameters.
| Performance Classification | Specific Performance | Description |
|---|---|---|
| PA6 Physical Properties | Appearance | Translucent or opaque milky white crystalline polymer. |
| Density | 1.13 – 1.15 g/cm³. | |
| Water Absorption | The equilibrium water absorption rate is 3.5%, with strong hygroscopicity, and many quality characteristics of its products are affected by hygroscopicity. | |
| Solubility | Resistant to cyclohexanone and aromatic solvents, insoluble in common solvents such as water. | |
| PA6 Mechanical Properties | Tensile Strength | > 60.0 MPa. |
| Elongation at Break | > 30%. | |
| Flexural Strength | 90.0 MPa. | |
| Notch Impact Strength | > 5 kJ/m². | |
| Wear Resistance | Excellent, with self-lubricating properties, and is often used to manufacture wear-resistant parts such as bearings. | |
| PA6 Thermal Properties | Melting Point | 215 – 225℃. |
| Thermal Decomposition Temperature | > 300℃. | |
| Operating Temperature Range | -40℃ – It can maintain its properties at relatively high temperatures, but the long-term use temperature is generally recommended to be around 80℃ – 100℃. Its glass fiber reinforced varieties have higher heat resistance. | |
| PA6 Electrical Properties | Electrical Insulation | Relatively good, and can be used for electrical components, etc., but it is slightly worse than some special electrical insulating materials and is affected by environmental humidity. |
| PA6 Chemical Properties | Chemical Corrosion Resistance | It has good chemical resistance, but its acid resistance is slightly weak, and its tolerance to strong oxidants and other chemicals is limited, with different stabilities in different chemical media. |
| PA6 Other Properties | Molding Shrinkage | For products without additives, the shrinkage rate is between 1% and 1.5%. Adding glass fiber additives can reduce the shrinkage rate to about 0.3%. |
| Processing Performance | The melt temperature range is relatively wide, usually between 230℃ and 280℃, with 250℃ – 280℃ for reinforced varieties; the mold temperature is generally recommended to be 80℃ – 90℃, which significantly affects the crystallinity and mechanical properties of the product. |
3. PA12 polyamide 12 or nylon 12
PA12 is a linear, semi-crystalline – crystalline thermoplastic material from butadiene. Its properties are similar to PA11, but the crystal structure is different. PA12 is a good electrical insulator and like other polyamides will not affect the insulation performance due to moisture.
It has good impact resistance and chemical stability. PA12 has many improved varieties in terms of plasticizing properties and strong properties. Compared with PA6 and PA66, these materials have lower melting point and density, and have very high moisture regain.
PA12 has no resistance to strong oxidizing acids. The viscosity of PA12 mainly depends on humidity, temperature and storage time. It flows very well. The shrinkage rate is between 0.5% and 2%, which mainly depends on the material type, wall thickness and other process conditions.
| Performance Classification | PA12 |
| Physical Properties | Translucent or opaque milky white crystalline polymer, density is 1.01-1.03g/cm³, melting point is 172-180℃, water absorption rate is about 0.25%, molding shrinkage rate is 0.5%-2%, good fluidity |
| Mechanical Properties | It has excellent wear resistance, impact resistance and self-lubricating property. Its strength and stiffness are slightly lower than those of PA6, but its high impact resistance enables it to maintain good physical properties even at low temperatures. The notched impact strength is greater than 5kJ/m² |
| Thermal Properties | The long-term service temperature range is 80℃-90℃, the thermal decomposition temperature exceeds 350℃, the melting temperature is 240-300℃, the mold temperature is 30-100℃, it has good low-temperature toughness, and the glass transition temperature is generally about -40℃ |
| Electrical Properties | It is a good electrical insulator, and its insulation performance is not affected by humidity |
| Chemical Properties | It is resistant to chemicals such as alkalis, greases, solvents, and aromatic hydrocarbons, but not resistant to concentrated inorganic acids and chlorinated hydrocarbons. It can tolerate certain detergents under certain conditions |
4. PA66 polyamide 66 or nylon 66
PA66 has a higher melting point among polyamide materials. It is a semi-crystalline – crystalline material. PA66 can also maintain strong strength and rigidity at higher temperatures.
PA66 is still hygroscopic after molding, and its degree mainly depends on the composition of the material, wall thickness and environmental conditions. The effect of hygroscopicity on geometric stability must be considered during product design. In order to improve the mechanical properties of PA66, various modifiers are often added.
Glass is the most common additive, and sometimes synthetic rubber, such as EPDM and SBR, is added to improve impact resistance. PA66 is less viscous and therefore flows well (but not as well as PA6). This property can be used to process very thin components. Its viscosity is sensitive to temperature changes.
The shrinkage of PA66 is between 1% and 2%, adding glass fiber additives can reduce the shrinkage to 0.2% to 1%. The difference in shrinkage in the flow direction and the direction perpendicular to the flow direction is larger. PA66 is resistant to many solvents, but less resistant to acids and some other chlorinating agents.
| PA66 Properties | Details |
| Physical Properties | It is a translucent or opaque milky white crystalline polymer, with a density of 1.15g/cm³, a melting point of 252℃, a brittle temperature of -30℃, a thermal decomposition temperature greater than 350℃, a continuous heat-resistant temperature of 80 – 120℃, an equilibrium water absorption rate of 2.5%, a molding shrinkage rate of 1% – 2%, which can be reduced to 0.2% – 1% by adding glass fiber additives, and it has relatively low viscosity and good fluidity |
| Mechanical Properties | It has excellent mechanical strength, toughness, wear resistance, self-lubricating property, high tensile strength, relatively good impact resistance, although slightly lower than that of PA6, and its rigidity and strength are even higher after glass fiber reinforcement |
| Thermal Properties | It can maintain stable properties in the temperature range of -40°C to 120°C, and still maintain strong strength and rigidity at relatively high temperatures. Its thermal stability and antioxidant property enable it to be used at a high temperature of 260℃ for a long time |
| Electrical Properties | It has excellent electrical insulation performance, with high volume resistance and high breakdown voltage resistance |
| Chemical Properties | It is resistant to corrosion by acids, alkalis, most inorganic salt solutions, halogenated hydrocarbons, hydrocarbons, esters, ketones, etc., but is easily soluble in polar solvents such as phenol and formic acid, and still has hygroscopicity after molding, which depends on the composition of the material, wall thickness, and environmental conditions |
5. PBT polybutylene terephthalate
PBT is one of the toughest engineering thermoplastics. It is a semi-crystalline material with very good chemical stability, mechanical strength, electrical insulation properties and thermal stability. These materials have good stability under a wide range of environmental conditions.
PBT has very weak hygroscopic properties. The tensile strength of non-reinforced PBT is 50MPa, and that of glass-added PBT is 170MPa. Too much glass additive will cause the material to become brittle. The crystallization of PBT is very rapid, which will cause bending deformation due to uneven cooling.
For materials with glass additives, the shrinkage in the process direction can be reduced, but the shrinkage in the direction perpendicular to the process is basically the same as that of ordinary materials.
Generally, the shrinkage rate of materials is between 1.5% and 2.8%. Materials with 30% glass additive shrink between 0.3% and 1.6%. The melting point (225 ℃) and high temperature deformation temperature are lower than PET materials.
Vicat softening temperature is about 170 ℃. The glass transition temperature (glass trasitio temperature) is between 22°C and 43°C. Due to the high crystallization rate of PBT, its viscosity is low and the cycle time of plastic part processing is generally low.
| PBT Properties | Details |
| Physical Properties | It is a milky white translucent to opaque, crystalline thermoplastic polyester. The density is 1.30 – 1.38 g/cm³. The melting point is 220 – 267℃. The glass transition temperature is 20 – 40℃. It has a fast crystallization speed and low viscosity. The molding shrinkage rate is 1.5% – 3.0%, generally between 1.5% – 2.8% for non-reinforced type, and between 0.3% – 1.6% for materials with 30% glass additives. It has low water absorption, only 0.1%. The Vicat softening temperature is about 170℃. |
| Mechanical Properties | It has excellent mechanical strength, high rigidity and hardness. The tensile strength can reach 50 MPa, and that of PBT with glass additives can reach 170 MPa. The elongation at break is 60% – 250%. It has a high tensile modulus and high impact resistance. It has excellent wear resistance due to its low friction coefficient and good self-lubricating property. However, its notched impact strength is low, and its rigidity and strength are even higher after glass fiber reinforcement. |
| Thermal Properties | It can maintain stable properties in the temperature range of -40°C to 120°C. The heat distortion temperature is 150℃ at 0.45 MPa and 60℃ at 1.8 MPa. It can work at 140℃ for a long time. The melting point is about 225℃. It has excellent thermal stability and can maintain strong strength and rigidity at high temperatures. |
| Electrical Properties | It has excellent electrical insulation performance, with high volume resistance, a dielectric strength of 20 kV/mm, a dielectric constant of 3.2 at 1 kHz, and a dielectric loss of 0.002 at 1 kHz. It has a high breakdown voltage resistance. Its low dielectric constant and low dielectric loss make it suitable for the field of electronics and electrical appliances. |
| Chemical Properties | It is resistant to the corrosion of diluted acids, alkalis, alcohols, aromatic hydrocarbons, greases, oils, ketones, etc. However, it is easily eroded by halogenated hydrocarbons and has poor hydrolysis resistance. It will undergo hydrolysis reaction under the action of high-temperature water or water vapor. Strong acids and alkalis can degrade it. It still has low hygroscopicity after molding, which depends on the composition of the material, wall thickness, and environmental conditions. |
6. PC polycarbonate
PC is an amorphous engineering material with exceptional impact strength, thermal stability, gloss, bacteriostatic properties, flame retardant properties, and stain resistance. PC has a very high notched impact strength and a very low shrinkage rate, generally 0.1% to 0.2%.
PC has good mechanical properties, but poor flow properties, so the injection molding process of this material is more difficult. When choosing which quality PC material to use, the final expectation of the product should be the benchmark.
If the plastic part requires high impact resistance, then use low flow rate PC material; on the contrary, you can use high flow rate PC material, which can optimize the injection molding process.
PC polycarbonate Chemical Properties
| Items | Details |
|---|---|
| Corrosion Resistance | It is resistant to organic acids, dilute inorganic acids, salts, oils, aliphatic hydrocarbons, and alcohols, but not resistant to chlorohydrocarbons, dilute alkalis, bromine water, concentrated acids, amines, ketones, and esters. It can be dissolved in solvents such as dichloromethane, dichloroethane, and cresol. |
| Hydrolysis Resistance | It has poor hydrolysis resistance and cannot be used for products that repeatedly withstand high-pressure steam. It is not resistant to hot water above 60℃, and long-term contact will lead to stress cracking and loss of toughness. |
| UV Resistance | It is not good and needs to add UV absorbers. |
| Oxidation Resistance | It has good resistance to air and ozone. |
| Electrical Insulation | It is an excellent E (120℃) grade insulating material. |
PC polycarbonate Physical Properties
| Items | Details |
|---|---|
| Appearance | It is usually colorless and transparent material, and can also appear slightly yellow or white due to different processing and additives. |
| Density | 1.18 – 1.20 g/cm³ |
| Molding Shrinkage | 0.5 – 0.8% |
| Molding Temperature | 230 – 320℃ |
| Drying Conditions | 110 – 120℃, 8 hours |
| Long-term Service Temperature | -60℃ – 120℃ |
| Transparency | It has excellent transparency, similar to glass, with a light transmittance of up to 93%, making it one of the excellent optical plastic varieties. |
| Mechanical Strength | The strength is higher than that of general plastics, with the advantages of rigidity and toughness. It has good tensile strength and flexural strength, which is less affected by temperature. Its impact performance is one of the better ones among thermoplastic plastics. However, it has poor resistance to stress cracking, high notch sensitivity, and average wear resistance. |
| Creep Resistance | It is better than PA and POM, with good dimensional stability. |
| Thermal Properties | It has good resistance to high and low temperatures and can be used in the temperature range of -130℃ – 130℃. The heat distortion temperature can reach 130℃ – 140℃. It has small thermal conductivity and linear expansion coefficient, and has good flame retardancy, belonging to self-extinguishing materials. |
| Electrical Properties | The insulation performance is average, but the electrical properties change slightly in a wide range of temperature and humidity. For example, the dielectric constant and dielectric loss tangent remain almost unchanged in the range of 23℃ – 125℃. |
| Water Absorption Rate | It is relatively low, about 0.15%. |
7. PC/ABS Alloy polycarbonate and acrylonitrile-butadiene-styrene copolymers and mixtures
PC/ABS alloy has combined properties of both PC and ABS. Examples include the easy processability of ABS and the excellent mechanical properties and thermal stability of PC. The ratio of the two will affect the thermal stability of PC/ABS material. The PC/ABS hybrid material also exhibits excellent flow characteristics.
PC/ABS alloy Physical Properties and Chemical Properties
| Performance Classification | Specific Performance | Detailed Description |
|---|---|---|
| Physical Properties | Specific Gravity | Generally between 1.05 – 1.20 g/cm³, for example, the specific gravity of PC-510 of PC/ABS from Chi Mei is 1.16 – 1.17 g/cm³. |
| Melt Flow Rate | For example, under the condition of 260°C/2.16 kg, the melt flow rate of PC-510 of PC/ABS from Chi Mei is 22 g/10 min. | |
| Melt Volume Flow Rate | Under the condition of 260°C/2.16 kg, the melt volume flow rate of PC-510 of PC/ABS from Chi Mei is 23.5 cm³/10 min. | |
| Shrinkage Rate | The flow shrinkage rate is generally about 0.4% – 0.6%, such as the shrinkage rate of PC-510 is 0.40% – 0.60%. | |
| Water Absorption Rate | Under the condition of 23°C and 24 hours, the water absorption rate is about 0.40%. | |
| Hardness | The Rockwell hardness (R scale) is about 113, such as PC-510 of PC/ABS from Chi Mei. | |
| Heat Deflection Temperature | Under the condition of 1.8 MPa and unannealed, the temperature is about 76.0 – 78.0°C; after annealing, the temperature is about 87.0°C. | |
| Vicat Softening Temperature | Generally between 88.0 – 95.0°C, for example, the Vicat softening temperature of PC-510 of PC/ABS from Chi Mei is 94.0 – 95.0°C. | |
| Linear Thermal Expansion Coefficient | Between 40 to 100°C, the linear thermal expansion coefficient is 6.0E-5 to 8.0E-5 cm/cm/°C. | |
| Chemical Properties | Chemical Stability | It has good chemical stability and is not prone to chemical reactions in general chemical environments, but it is not resistant to the long-term erosion of strong oxidants, strong acids, strong alkalis and other corrosive substances. |
| Hydrolysis Resistance | Some PC/ABS alloys with good hydrolysis resistance stability, such as HAC8250R, after being placed in a 95% RH, 100°C high temperature and high humidity environment for 1000 hours, the PC phase can still maintain more than 90% of the molecular weight, and the impact performance only decreases by 15%. | |
| Chemical Solvent Resistance | There are products with excellent chemical solvent resistance, such as PC/ABS used for automotive interiors, which is spray-free and can resist the erosion of common chemical solvents such as gasoline, alcohol, and cleaning agents. | |
| Flame Retardancy | It has certain flame retardancy. For example, the UL flame retardant grade of PC-510 of PC/ABS from Chi Mei is V-0 at 1.50 mm, 5VB at 2.00 mm, 5VB at 2.10 mm, and 5VA at 3.00 mm. |
8. PC/PBT Alloy Polycarbonate and Polybutylene terephthalate Alloy
PC/PBT has the combined properties of both PC and PBT, such as the high toughness and geometric stability of PC and the chemical stability, thermal stability and lubricating properties of PBT.
PC/PBT alloy Physical Properties and Chemical Properties
| Performance Classification | Specific Properties | Detailed Description |
|---|---|---|
| Physical Properties | Specific Gravity | Generally around 1.20 – 1.22 g/cm³. For example, the specific gravity of PC/PBT 5720 of Pier One Polymers is 1.22 g/cm³. |
| Melt Flow Rate | Usually between 6.0 – 15 g/10 min. For instance, the melt flow rate of PC/PBT alloy of Da Fon Environmental Technology is 10 – 15, and that of PC/PBT 5720 of Pier One Polymers is 6.0 g/10 min. | |
| Tensile Stress | The yield strength can reach 60 MPa – 8800 psi, and the breaking strength can reach 58 MPa – 8100 psi. | |
| Tensile Strain | The yield strain is approximately 5%, and the breaking strain is approximately 100%. | |
| Tensile Modulus | About 343000 psi – 340.09 ksi. | |
| Flexural Stress | The yield strength can reach 13400 psi – 13500 psi. | |
| Flexural Modulus | About 339000 psi – 2.3448 Gpa. | |
| Notch Impact Strength | Such as the notch impact strength of PC/PBT 5720 of Pier One Polymers is 7.487 J/cm. | |
| Heat Deflection Temperature | At 1.8 MPa, the temperature can reach around 107°C. | |
| Mold Shrinkage | Approximately 0.6% – 0.9%. | |
| Water Absorption | Less than or equal to 0.020%. | |
| Chemical Properties | Chemical Stability | It has good tolerance to diluted acids, alcohols, aromatic hydrocarbons, ketones, solvents, oils, and fats, etc. It is suitable for manufacturing plastic parts exposed to organic solvents, gasoline, and oils. |
| Hydrolysis Resistance | The hydrolysis resistance is relatively poor, but it can be improved by adding appropriate additives. | |
| Weather Resistance | Usually good, and it can maintain its performance and appearance for a long time in outdoor environments. | |
| Flame Retardancy | It can reach different flame retardant standards such as UL94 V-0 by adding flame retardants. |
9. HDPE High Density Polyethylene
The high crystallinity of HDPE leads to its high density, tensile strength, high temperature distortion temperature, viscosity and chemical stability.
HDPE has stronger penetration resistance than LDPE. HDPE has low impact strength. The properties of HDPE are mainly controlled by density and molecular weight distribution. HDPE suitable for injection molding has a narrow molecular weight distribution.
For the density of 0.91~0.925g/cm3, we call it the first type of HDPE; for the density of 0.926~0.94g/cm3, it is called the second type of HDPE; for the density of 0.94~0.965g/cm3, it is called Type III HDPE. The material has good flow characteristics with an MFR of 0.1 to 28. The higher the molecular weight, the worse the flow characteristics of LDPE, but better impact strength.
LDPE is a semi-crystalline material with high shrinkage after molding, between 1.5% and 4%. HDPE is prone to environmental stress cracking. Cracking can be mitigated by using materials with very low flow characteristics to reduce internal stresses. HDPE is easy to dissolve in hydrocarbon solvents when the temperature is higher than 60 ℃, but its resistance to dissolution is better than that of LDPE.
Properties of HDPE Alloy
| Classification of Properties | Specific Properties | Description |
|---|---|---|
| Physical Properties | Density | Generally between 0.93 – 0.97 g/cm³ |
| Melting Point | Between 120 – 140°C | |
| Degree of Crystallinity | Approximately 61% | |
| Hardness and Modulus | High, with good rigidity and load-bearing capacity | |
| Tensile Strength | Stronger than low-density polyethylene. For example, the tensile strength of HDPE can reach 38 MPa, while that of LDPE is only 21 MPa | |
| Impact Resistance | Medium to high molecular weight grades have excellent impact resistance and perform well even at -40°F | |
| Thermal Conductivity | 0.54 W/m·°C | |
| Specific Heat Capacity | 1331 – 2400 J/kg·K | |
| Molding Shrinkage Rate | Generally between 1.5% – 3.6% | |
| Water Absorption | Minimal, non-hygroscopic, with good water vapor resistance | |
| Chemical Properties | Chemical Stability | Resistant to most acids, bases, and salts, but can be corroded by certain strong oxidants, aromatic hydrocarbons, and halogenated hydrocarbons, such as concentrated nitric acid, xylene, carbon tetrachloride, etc. |
| Hydrolysis Resistance | Has relatively good hydrolysis resistance | |
| Weather Resistance | Good, can maintain performance and appearance for a long time in outdoor environments, but will age when exposed to ultraviolet light for a long time. The aging phenomenon can be alleviated by adding UV stabilizers. | |
| Oil Resistance | Has good tolerance to general oils and can be used for manufacturing parts in contact with oils | |
| Flame Retardancy | It has a certain degree of flame retardancy itself, but usually needs to add flame retardants to improve its flame retardant level to meet the fire prevention requirements of different application scenarios. |
10. LDPE low density polyethylene
The density of commercial LDPE materials is 0.91~0.94 g/cm3. LDPE is permeable to gases and water vapor. LDPE has a high coefficient of thermal expansion and is not suitable for processing long-term products.
If the density of LDPE is between 0.91~0.925 g/cm3, then its shrinkage rate is between 2%~5%; if the density is between 0.926~0.94 g/cm3, then its shrinkage rate is between 1.5%~4%. between. The current actual shrinkage rate also depends on the injection molding process parameters.
LDPE is resistant to many solvents at room temperature, but aromatic and chlorinated hydrocarbon solvents can cause it to swell. Similar to HDPE, LDPE is prone to environmental stress cracking.
Properties of LDPE
| Classification of Properties | Specific Properties | Description |
|---|---|---|
| Physical Properties | Appearance | Milky white, odorless, tasteless, non-toxic, waxy granules with no luster on the surface |
| Density | 0.910 – 0.925 g/mL | |
| Melting Point | 110 – 115℃ | |
| Degree of Crystallinity | 45% – 65% | |
| Flexibility | Good, with excellent flexibility and extensibility, not easily embrittled even in low temperature environments | |
| Transparency | Slightly milky white and transparent, with relatively high transparency. Its transparency decreases with the increase of crystallinity, and at a certain crystallinity, the transparency increases with the increase of molecular weight | |
| Tensile Strength | 0.20 – 0.40 N/mm² | |
| Notch Impact Strength | No breakage KJ/m² | |
| Thermal Expansion Coefficient | 100 – 220×10⁻⁶ | |
| Maximum Continuous Use Temperature | 65℃ | |
| Water Absorption | Minimal, non-hygroscopic, with good water vapor resistance | |
| Gas Permeability | Relatively high gas permeability | |
| Electrical Insulation | Excellent | |
| Chemical Properties | Chemical Stability | Resistant to hydrochloric acid, hydrofluoric acid, phosphoric acid, formic acid, amines, sodium hydroxide, potassium hydroxide, etc. at room temperature, but nitric acid and sulfuric acid have a strong destructive effect on it; it also has good tolerance to alkalis and general organic solvents |
| Hydrolysis Resistance | Relatively good | |
| Weather Resistance | Susceptible to aging under the action of ultraviolet light and heat, but has certain weather resistance. Carbon black has an excellent light shielding effect on it | |
| Oil Resistance | Poor, and products can be slowly swollen | |
| Oxidation Resistance | Prone to photo-oxidation, thermal oxidation, and ozone decomposition, and is easily degraded under the action of ultraviolet light | |
| Flammability | Easily flammable and continues to burn after leaving the fire |
11. PEI Polyethylenimine
PEI has strong high temperature stability, even if it is unreinforced PEI, it still has good toughness and strength. Therefore, the superior thermal stability of PEI can be used to make high-temperature heat-resistant devices.
PEI also has good flame retardancy, chemical resistance, and electrical insulation properties. The glass transition temperature is very high, reaching 215 ℃. PEI also has very low shrinkage and good mechanical properties in the same direction.
Properties of PEI
| Performance Classification | Specific Performance | Value or Description | Unit | Test Standard |
|---|---|---|---|---|
| Physical Properties | Density | 1.27 | g/cm³ | ISO 1183 |
| Water Absorption (24h) | 0.25 | % | ISO 62 | |
| Equilibrium Water Absorption | 1.3 | % | ISO 62 | |
| Linear Thermal Expansion Coefficient | 56.0 | µm/m-°C | ISO 11359 | |
| Thermal Conductivity (20°C) | 0.240 | W/m-K | ISO 22007-4 | |
| Glass Transition Temperature | 217 | °C | DIN EN ISO 3146 | |
| Melting Point | 217 | °C | DIN EN ISO 3146 | |
| Heat Deflection Temperature (0.46MPa) | 200 | °C | ISO 75 | |
| Heat Deflection Temperature (1.8MPa) | 190 | °C | ISO 75 | |
| Limiting Oxygen Index | 47 | % | ASTM D2863 | |
| Flame Retardancy | V-0 | – | UL 94 | |
| Shrinkage – Flow (0.125 in) | 0.0060 in/in | – | ASTM D955 | |
| Melt Flow Rate (337°C/6.6 kg) | 4.2 | g/10 min | ASTM D1238 | |
| Chemical Properties | Acid Resistance | Good, has better tolerance to dilute acids | – | – |
| Alkali Resistance | Good, can resist certain concentrations of alkali solution, but the alkali resistance is general under heating conditions | – | – | |
| Aromatic Hydrocarbon Resistance | Good | – | – | |
| Alcohol Resistance | Good, can tolerate common alcohol solvents | – | – | |
| Halogenated Hydrocarbon Resistance | Limited, prone to stress cracking in chlorinated solvents | – | – | |
| Hydrolysis Resistance | Good, has better hydrolysis resistance | – | – |
12. PET polyethylene terephthalate
The glass transition temperature of PET is around 165 °C, and the material crystallization temperature ranges from 120 to 220 °C. PET is highly hygroscopic at high temperatures. For glass fiber reinforced PET materials, bending deformation is also very easy to occur at high temperatures.
The degree of crystallinity of the material can be increased by adding a crystallization enhancer. Transparent products processed with PET have gloss and heat distortion temperature. Special additives such as mica can be added to PET to minimize bending deformation. Transparent parts can also be obtained with unfilled PET materials if lower mold temperatures are used.
Properties of PET
| Performance Classification | Specific Performance | Value or Description | Unit |
|---|---|---|---|
| Physical Properties | Density | 1.30 – 1.33 (amorphous) 1.33 – 1.38 (crystalline) | g/cm³ |
| Melting Point | 250 – 265 | °C | |
| Glass Transition Temperature | 67 – 81 | °C | |
| Heat Deflection Temperature | 85 | °C | |
| Brittleness Temperature | -70 | °C | |
| Long-term Service Temperature | 120 | °C | |
| Short-term Service Temperature | 150 | °C | |
| Linear Expansion Coefficient | |||
| Thermal Conductivity | 0.15 – 0.24 | W/(m·K) | |
| Refractive Index | 1.57 – 1.58 | – | |
| Water Absorption (24h) | 0.16 | % | |
| Equilibrium Water Absorption | <0.7 | % | |
| Limiting Oxygen Index | 21 | % | |
| Transparency | Colorless and transparent (amorphous) Opaque milky white (crystalline) | – | |
| Chemical Properties | Acid Resistance | Resistant to dilute acids, but not resistant to concentrated acids such as concentrated sulfuric acid | – |
| Alkali Resistance | Generally resistant to dilute alkalis, sensitive to ammonia water, etc., and prone to hydrolysis when in contact with water at high temperature | – | |
| Alcohol Resistance | Good | – | |
| Aromatic Hydrocarbon Resistance | Moderate | – | |
| Halogenated Hydrocarbon Resistance | Moderate | – | |
| Oil Resistance | Good | – | |
| Resistance to Organic Solvents | Stable to general non-polar organic solvents, resistant to some polar solvents at room temperature, and can be dissolved in polar solvents such as phenol and tricresol when heated | – |
13. PETG ethylene glycol modified – polyethylene terephthalate
PETG is a transparent, non-crystalline material. The glass transition temperature is 88 °C. The permissible range of injection molding process conditions of PETG is wider than that of PET, and it has comprehensive characteristics of transparency, high strength and high willfulness.
Performance Classification of PETG
| Performance Classification | Specific Performance | Numerical Value or Description | Unit | Test Method |
|---|---|---|---|---|
| Physical Properties | Density | 1.27 | g/cm³ | ASTM D792 |
| Hardness (Rockwell Hardness, 23°C) | 106 – 116 | – | ASTM D785 | |
| Shrinkage – Flow | 0.010 – 0.015 | in/in | ASTM D955 | |
| Vicat Softening Temperature | 74.0 | °C | ASTM D1525 | |
| Glass Transition Temperature, Tg | 75.0 | °C | ASTM D1525 | |
| Haze | 0.70 | % | ASTM D1003 | |
| Water Vapor Transmission Rate | 0.490 | g/m²/day | ASTM F372 | |
| Oxygen Transmission Rate | 23.0 | cc-mm/m²-24hr-atm | ASTM D3985 | |
| Tensile Strength (at Break) | 22.0 | MPa | ASTM D638 | |
| Tensile Strength (at Yield) | 51.0 | MPa | ASTM D638 | |
| Elongation at Break | 184 | % | ASTM D638 | |
| Flexural Strength | 73.0 | MPa | ASTM D790 | |
| Notched Izod Impact Strength @ -40.0°C | 0.400 | J/cm | ASTM D256 | |
| Notched Izod Impact Strength @ 23.0°C | 0.650 | J/cm | ASTM D256 | |
| Unnotched Izod Impact Strength @ -40.0°C | NB | – | ASTM D4812 | |
| Unnotched Izod Impact Strength @ 23.0°C | NB | – | ASTM D4812 | |
| Puncture Energy @ Thickness 3.20mm, -40.0°C | 24.0 | J | ASTM D3763 | |
| Puncture Energy @ Thickness 3.20mm, 23.0°C | 33.0 | J | ASTM D3763 | |
| Chemical Properties | Chemical Resistance | Resistant to a variety of chemicals and common cleaning agents, meeting the requirements of food contact management | – | – |
| Acid Resistance | Has good tolerance to general acids, but may be affected to some extent under strong acid conditions | – | – | |
| Alkali Resistance | Resistant to alkali to a certain extent, but performance may decline in a strong alkaline environment | – | – | |
| Alcohol Resistance | Good, can be used in some packaging applications for substances containing alcohols | – | – | |
| Water Resistance | Has good water resistance and is not easily decomposed by water, but may be slightly affected by long-term exposure to a humid environment | – | – | |
| Oxidation Resistance | Has a certain resistance to general oxidation environments, but may undergo oxidation reactions under strong oxidation conditions | – | – | |
| Solvent Resistance | Shows good tolerance to common organic solvents, but the degree of influence varies for different solvents, and there may be slight swelling in some polar solvents | – | – |
14. PMMA polymethyl methacrylate
PMMA has excellent optical properties and weather resistance properties. The penetration of white light is as high as 92%. PMMA products have very low birefringence and are especially suitable for making video discs, etc.
PMMA has room temperature creep properties. As the load increases and the time increases, it can lead to stress cracking. PMMA has good impact resistance properties.
Properties of Acrylic
| Performance Classification | Specific Performance | Numerical Value or Description | Unit |
|---|---|---|---|
| Physical Properties | Density | 1.14 – 1.19 | g/cm³ |
| Hardness (Barcol) | 49.0 – 50.0 | – | |
| Light Transmittance | Above 92%, with the highest visible light transmittance up to 93.0% | % | |
| Refractive Index | 1.49 – 1.49 | – | |
| Tensile Strength (Ultimate) | 62.0 – 83.0 | MPa | |
| Tensile Strength (Yield) | 64.8 – 83.4 | MPa | |
| Elongation at Break | 2% – 10% | % | |
| Elastic Modulus | 2.4 – 3.1 | GPa | |
| Flexural Strength | 90.0 – 130.0 | MPa | |
| Compressive Strength | 85.0 – 125.0 | MPa | |
| Impact Strength (Notched) | 1.6 – 2.8 | kJ/m² | |
| Impact Strength (Unnotched) | No break | – | |
| Heat Deflection Temperature | 70.0 – 100.0 | °C | |
| Maximum Service Temperature (in Air) | 70.0 – 200.0 | °C | |
| Minimum Service Temperature (in Air) | -40.0 – 32.2 | °C | |
| Linear Expansion Coefficient | 6 – 8×10⁻⁵ | 1/°C | |
| Water Absorption | 0.130 – 0.800 | % | |
| Flammability | Flammable, not self-extinguishing. The flame is yellow with black smoke during combustion, and there is no ash left after burning. | – | |
| Chemical Properties | Acid Resistance | Has certain tolerance to dilute acids, but may be eroded in concentrated acids. It depends on the type and concentration of acids and other factors. | – |
| Alkali Resistance | Not resistant to strong alkalis, which will damage it. | – | |
| Resistance to Organic Solvents | Has good tolerance to common organic solvents, but some organic solvents may cause swelling or micro-cracks on the surface, etc. | – | |
| Water Resistance | Has good water resistance and is not easily decomposed by water, but its performance may be affected by long-term exposure to a humid environment. | – | |
| Oxidation Resistance | Has a certain resistance to oxidation, but may undergo oxidation reactions under strong oxidation conditions. | – | |
| Weather Resistance | Excellent. It can resist the erosion of natural environmental factors such as ultraviolet rays, wind, and rain for a long time, and is not easy to change color or age. | – | |
| Chemical Stability | Good. It can tolerate many chemicals at room temperature, but may have chemical reactions in high-temperature or specific chemical environments. | – |
15. POM polyoxymethylene
POM is a tough and elastic material with good creep resistance, geometric stability and impact resistance even at low temperatures. POM is available in both homopolymer and copolymer materials.
Homopolymer materials have good tensile strength and fatigue resistance, but are not easy to process. Copolymer materials have good thermal stability, chemical stability and easy processing. Both homopolymer and copolymer materials are crystalline materials and are not easy to absorb moisture.
The high degree of crystallinity of POM causes it to have a fairly high shrinkage rate, which can reach as high as 2%~3.5%. There are different shrinkage rates for various reinforced materials.
Properties of POM
| Performance Classification | Specific Performance | Numerical Value or Description | Unit |
|---|---|---|---|
| Physical Properties | Density | 1.39 – 1.43 | g/cm³ |
| Melting Point | 175 | °C | |
| Tensile Strength (Yield) | 63 – 70 | MPa | |
| Elongation at Yield | 10% – 15% | % | |
| Elongation at Break | 15% | % | |
| Impact Strength (Unnotched) | 108 | KJ/m² | |
| Impact Strength (Notched) | 7.6 | KJ/m² | |
| Rockwell Hardness | 135 | MPa | |
| Shore Hardness | 85 | MPa | |
| Flexural Strength | – | MPa | |
| Elastic Modulus | 2600 | MPa | |
| Softening Temperature | 150 | °C | |
| Heat Deflection Temperature | 155 | °C | |
| Coefficient of Linear Expansion | 1.1 | 1/°C | |
| Thermal Conductivity | 0.31 | W/(m·K) | |
| Friction Coefficient | 0.35 | – | |
| Water Absorption | 0.2% – 0.25% | % | |
| Appearance | Smooth surface, glossy, light yellow or white | – | |
| Crystallinity | 70% – 85% | % | |
| Shrinkage Rate | 1.5% – 3.5% | % | |
| Chemical Properties | Acid Resistance | Not resistant to strong acids, has certain tolerance to weak acids | – |
| Alkali Resistance | Not resistant to strong alkalis | – | |
| Resistance to Organic Solvents | Good, except for a few organic solvents such as phenols and organic halides, it is stable to other common organic solvents | – | |
| Oil Resistance | Good | – | |
| Oxidation Resistance | General, may be oxidized under strong oxidation conditions | – | |
| Water Resistance | Good, low water absorption, not easily hydrolyzed | – | |
| Weather Resistance | Poor, stabilizers need to be added for outdoor applications, ultraviolet rays may cause polymer degradation | – | |
| Chemical Stability | Stable to most chemicals except strong acids, strong alkalis, phenols, and organic halides |
16. PP Polypropylene
PP is a semi-crystalline material. It is harder and has a higher melting point than PE. Because the homopolymer PP temperature is very brittle above 0C, many commercial PP materials are random copolymers with 1 to 4% ethylene or clamp copolymers with higher ethylene content.
Copolymer PP materials have a low heat distortion temperature (100C), low transparency, low gloss, and low rigidity, but have stronger impact strength.
The strength of PP increases with the increase of ethylene content. The Vicat softening temperature of PP is 150°C. Due to the high degree of crystallinity, this material has very good surface stiffness and scratch resistance properties.
PP does not suffer from environmental stress cracking. Usually, PP is modified by adding glass fibers, metal additives or thermoplastic rubber.
Properties of PP
| Performance Classification | Specific Performance | Numerical Value or Description | Unit |
|---|---|---|---|
| Physical Properties | Density | 0.90 – 0.91 | g/cm³ |
| Melting Point | 164 – 170 (The melting point of 100% isotactic polypropylene is 176°C) | °C | |
| Tensile Strength | About 30MPa or slightly higher | MPa | |
| Elongation at Yield | – | % | |
| Impact Strength | Poor at room temperature and low temperature, but shows ductile fracture above the glass transition temperature with relatively better impact strength value | KJ/m² | |
| Rockwell Hardness | – | – | |
| Shore Hardness | – | – | |
| Flexural Strength | – | MPa | |
| Elastic Modulus | – | MPa | |
| Softening Temperature | – | °C | |
| Heat Deflection Temperature | – | °C | |
| Coefficient of Linear Expansion | – | 1/°C | |
| Thermal Conductivity | – | W/(m·K) | |
| Friction Coefficient | – | – | |
| Water Absorption | 0.01% | % | |
| Appearance | Non-toxic, odorless, tasteless, milky white, highly crystalline, with good surface gloss, can be transparent or translucent, and no burrs | – | |
| Crystallinity | – | % | |
| Shrinkage Rate | 1% – 2.5% | % | |
| Chemical Properties | Acid Resistance | Stable to most acids except concentrated sulfuric acid and concentrated nitric acid | – |
| Alkali Resistance | Stable | – | |
| Resistance to Organic Solvents | Unstable to low molecular weight aliphatic hydrocarbons, aromatic hydrocarbons, and chlorinated hydrocarbons, which will cause softening and swelling, but stable to other common organic solvents | – | |
| Oil Resistance | – | – | |
| Oxidation Resistance | – | – | |
| Water Resistance | Particularly stable to water | – | |
| Weather Resistance | Relatively good, but its performance may decline after long-term exposure to outdoor environment | – | |
| Chemical Stability | Good, and its chemical stability increases with the increase of crystallinity | – |
17. PPE polypropylene
Commercially available PPE or PPO materials are generally mixed with other thermoplastic materials such as PS, PA, etc. These hybrid materials are generally still referred to as PPE or PPO.
Blended PPE or PPO have much better processing characteristics than pure material. The properties vary depending on the ratio of mixtures such as PPO and PS. Blends incorporating PA 66 are chemically more stable at high temperatures. This material has little hygroscopicity and its products have excellent geometric stability.
The material mixed with PS is non-crystalline, while the material mixed with PA is crystalline. Adding glass fiber additives can reduce shrinkage to 0.2%.
This material also has excellent electrical insulating properties and a very low coefficient of thermal expansion. Its viscosity depends on the ratio of the mixture in the material, an increase in the ratio of PPO will result in an increase in viscosity.
Properties of PPE
| Performance Classification | Specific Performance | Numerical Value or Description | Unit |
|---|---|---|---|
| Physical Properties | Density | 1.06 – 1.10 | g/cm³ |
| Glass Transition Temperature | 85 – 211 (Typical value is around 210°C) | °C | |
| Melting Point | 260 – 268 | °C | |
| Tensile Modulus | 2.3 – 3.68 | GPa | |
| Tensile Strength | 55 | MPa | |
| Elongation at Break | 30% | % | |
| Flexural Strength | 75 | MPa | |
| Impact Strength | There is no single definite value. Its toughness, etc. are affected by many factors. Generally, it has certain toughness at room temperature and becomes brittle at low temperature. | – | |
| Rockwell Hardness | 118 – 122 | – | |
| Heat Deflection Temperature | 120 | °C | |
| Vicat Softening Temperature | 140 | °C | |
| Specific Heat Capacity | 1200 | J/kg·K | |
| Thermal Conductivity | 0.22 | W/m·K | |
| Coefficient of Linear Expansion | 90 | µm/m·K | |
| Water Absorption | 0.10% – 0.23% | % | |
| Appearance | Usually transparent or amber transparent granules, odorless, tasteless, non-toxic | – | |
| Shrinkage Rate | 0.0050 – 0.0070 in/in or 0.2% (when adding glass fiber additives) | ||
| Dielectric Constant (1MHz) | 2.7 | – | |
| Dielectric Strength | 19 | kV/mm | |
| Volume Resistivity | 10¹³Ω·m | – | |
| Chemical Properties | Acid Resistance | Stable to most acids, but strong acids such as concentrated sulfuric acid may degrade its performance. | – |
| Alkali Resistance | Stable | – | |
| Resistance to Organic Solvents | Unstable to aliphatic hydrocarbons, halogenated aliphatic hydrocarbons, and aromatic hydrocarbons, etc. It will swell and dissolve. It will cause stress cracking in ketones and esters solvents under stress. | – | |
| Water Resistance | Excellent, with low water absorption, and its physical properties decrease slightly after long-term immersion in hot water. | – | |
| Oxidation Resistance | It has certain antioxidant properties, but its performance may be affected in a long-term high-temperature oxidative environment. | – | |
| Light Resistance | Poor. It will change color and turn yellow after long-term use in sunlight or fluorescent light. | – | |
| Chemical Stability | Good, and its chemical stability increases with the increase of crystallinity. The blended material mixed with PA66 has stronger chemical stability at high temperature. | – | |
| Flame Retardancy | Oxygen index is 29, it is a self-extinguishing material, and it can meet UL94 standard by adding phosphorus-containing flame retardants. |
18. PS polystyrene
Most commercial PS are transparent, non-crystalline materials. PS has very good geometrical stability, thermal stability, optical transmission properties, electrical insulation properties and a very slight tendency to absorb moisture.
It is resistant to water and diluted inorganic acids, but it can be corroded by strong oxidizing acids such as concentrated sulfuric acid, and it can swell and deform in some organic solvents. Typical shrinkage is between 0.4 and 0.7%.
Properties of PS
| Performance Classification | Specific Performance | Numerical Value or Description | Unit |
|---|---|---|---|
| Physical Properties | Density | Amorphous: 1.04 – 1.06, Crystal: 1.11 – 1.12 | g/cm³ |
| Glass Transition Temperature | Above 100°C | °C | |
| Melting Point | 240 | °C | |
| Tensile Strength | General | – | |
| Elongation at Break | – | – | |
| Flexural Strength | – | – | |
| Impact Strength | Good at room temperature and decreases with decreasing temperature | – | |
| Rockwell Hardness | – | – | |
| Heat Deflection Temperature | – | °C | |
| Vicat Softening Temperature | – | °C | |
| Specific Heat Capacity | – | J/kg·K | |
| Thermal Conductivity | 0.116 at 30℃ | W/(m·K) | |
| Coefficient of Linear Expansion | Large | – | |
| Water Absorption | Small | – | |
| Appearance | Colorless transparent granules, high transparency of products, light transmittance can reach more than 90% | – | |
| Shrinkage Rate | 0.6 – 0.8% | – | |
| Dielectric Constant | – | – | |
| Dielectric Strength | – | – | |
| Volume Resistivity | 10²⁰ – 10²² | Ω·cm | |
| Chemical Properties | Acid Resistance | Stable to general acids, resistant to water and diluted inorganic acids, but corroded by strong oxidizing acids such as concentrated sulfuric acid | – |
| Alkali Resistance | Stable | – | |
| Resistance to Organic Solvents | Not resistant to organic solvents such as benzene and gasoline, and will swell and deform in some organic solvents | – | |
| Water Resistance | Good | – | |
| Oxidation Resistance | Has certain antioxidant properties | – | |
| Light Resistance | Poor, easily discolored after long-term exposure to light | – | |
| Chemical Stability | Good, but not as good as PP, PE, etc. | – | |
| Flame Retardancy | Has certain flame retardancy |
19. PVC (polyvinyl chloride)
Rigid PVC is one of the most widely used plastic materials. PVC material is a non-crystalline material. In actual use, PVC materials are often added with stabilizers, lubricants, auxiliary processing agents, pigments, anti-impact agents and other additives.
PVC material has non-flammability, high strength, resistance to climate change and good geometric stability. PVC is highly resistant to oxidizing agents, reducing agents and strong acids.
However, it can be corroded by concentrated oxidizing acids such as concentrated sulfuric acid and concentrated nitric acid, and it is not suitable for contact with aromatic hydrocarbons and chlorinated hydrocarbons.
The melting temperature of PVC is a very important process parameter during processing, if this parameter is improper, it will lead to the problem of material decomposition.
The flow characteristics of PVC are rather poor and its process latitude is very narrow. In particular, PVC materials with large molecular weight are more difficult to process (such materials are usually added with lubricants to improve flow characteristics), so PVC materials with low molecular weight are usually used. The shrinkage rate of PVC is quite low, generally 0.2~0.6%.
Properties of PVC
| Performance Classification | Specific Performance | Numerical Value or Description | Unit |
|---|---|---|---|
| Physical Properties | Density | Pure PVC: 1.4g/cm³, PVC plastics with plasticizers and fillers added: generally 1.15 – 2.00g/cm³ | g/cm³ |
| Glass Transition Temperature | 77 – 90℃ | °C | |
| Softening Temperature | 80 – 85℃ | °C | |
| Melting Point | Approximately 212℃ | °C | |
| Heat Deflection Temperature (under 1.82MPa load) | 70 – 71℃ | °C | |
| Thermal Conductivity | 0.16W/(m·K) | W/(m·K) | |
| Coefficient of Linear Expansion | 8×10⁻⁵/K | /K | |
| Heat Capacity | 0.9kJ/(kg·K) | kJ/(kg·K) | |
| Water Absorption | 0.04 – 0.4 | / | |
| Refractive Index | 1.52 – 1.55 | / | |
| Mechanical Strength | Rigid PVC has good tensile, flexural, compressive, and impact resistance; the softness and elongation at break of soft PVC increase, but its brittleness, hardness, and tensile strength decrease | / | |
| Appearance | Amorphous white powder, intrinsically slightly yellowish and translucent with luster. With different amounts of additives, it can be divided into soft and hard polyvinyl chloride. The hardness of hard products is higher than that of low-density polyethylene but lower than that of polypropylene. Soft products are soft and tough, with a sticky feel, and whitening may occur at the bending points | / | |
| Shrinkage Rate | 0.6 – 1.5% | / | |
| Dielectric Constant | / | / | |
| Dielectric Strength | / | / | |
| Volume Resistivity | / | Ω·cm | |
| Chemical Properties | Acid Resistance | Resistant to hydrochloric acid of any concentration, sulfuric acid below 90%, and nitric acid of 50 – 60% at room temperature. Generally stable to acids, but corroded by strong oxidizing acids such as concentrated sulfuric acid | / |
| Alkali Resistance | Stable to caustic soda solution below 20% at room temperature | / | |
| Resistance to Organic Solvents | Insoluble in water, alcohol, gasoline, etc. Difficult to dissolve in common solvents, but can dissolve in ether, ketone, chlorinated aliphatic hydrocarbons, and aromatic hydrocarbons, and will swell in some organic solvents | / | |
| Chemical Stability | Good, quite stable to salts | / | |
| Oxidation Resistance | Has certain antioxidant properties, but relatively weak | / | |
| Light Resistance | Poor, easily discolored, degraded in flexibility, and finally brittle after long-term exposure to light | / | |
| Flame Retardancy | Has flame retardancy with a flame retardant value of above 40, but releases hydrogen chloride and other toxic gases such as dioxin during combustion | / | |
| Decomposition Characteristics | Decomposes to produce hydrogen chloride above 100℃ or after long-term exposure to sunlight, and may further autocatalytically decompose. It starts to decompose significantly around 170℃. The decomposition due to heat causes discoloration, from white to light yellow, red, brown, and finally black | / | |
| Reaction Activity | Relatively low, chemically inactive under general conditions, but can undergo substitution, addition, and other reactions under specific conditions | / |
20. SA styrene-acrylonitrile copolymer
SA is a hard, transparent material. The styrene component makes SA hard, transparent and easy to process; the acrylonitrile component makes SA chemically and thermally stable. SA has strong load bearing capacity, chemical reaction resistance, thermal deformation resistance and geometric stability.
Adding glass fiber additives to SA can increase strength and thermal deformation resistance, and reduce thermal expansion coefficient. The Vicat softening temperature of SA is about 110 °C. The deflection temperature under load is about 100 °C. The shrinkage rate of SA is about 0.3~0.7%.
Properties of SA
| Performance Classification | Specific Performance | Numerical Value or Description | Unit |
|---|---|---|---|
| Physical Properties | Appearance | Hard, transparent material | / |
| Vicat Softening Temperature | Approximately 110°C | °C | |
| Deflection Temperature under Load | Approximately 100°C | °C | |
| Shrinkage Rate | Approximately 0.3 – 0.7% | / | |
| Transparency | Very high, higher than PS | / | |
| Density | No definite standard value, between that of polystyrene and polyacrylonitrile | g/cm³ | |
| Hardness | Relatively high, the styrene component makes it hard | / | |
| Mechanical Strength | Has a strong load-bearing capacity | / | |
| Coefficient of Thermal Expansion | Can be reduced by adding glass fiber additives | / | |
| Chemical Properties | Chemical Stability | The acrylonitrile component gives it good chemical stability, enabling it to resist the erosion of many chemicals | / |
| Thermal Stability | The acrylonitrile component gives it better thermal stability, with a higher softening temperature and impact strength than PS | / | |
| Solvent Resistance | Has good tolerance to common organic solvents, but can be dissolved in certain specific organic solvents | / | |
| Reaction Activity | Relatively stable, with low chemical reactivity under general conditions, but can react under specific conditions | / |