PBT, also known as polybutylene terephthalate, is a polyester in the series, synthesized from 1.4-pbt butylene glycol (1.4-Butyleneglycol) and terephthalic acid (PTA) or dimethyl terephthalate (DMT) through condensation polymerization. It is then processed into a milky, translucent to opaque, crystalline thermoplastic polyester resin through blending. Together with PET, it is collectively referred to as thermoplastic polyester or saturated polyester.PBT, also known as thermoplastic polyester plastic, is suitable for various industries. It typically contains additives or is blended with other plastics, allowing for the production of different specifications based on the proportion of additives. Due to its heat resistance, pharmaceutical properties, excellent electrical characteristics, low water absorption, and good luster, PBT is widely used in electronics, automotive parts, machinery, household goods, and more. PBT products are also collectively referred to as the "Five Major General-Purpose Engineering Plastics" along with PPE, PC, POM, and PA.
| Physical Properties | Rated Value | Unit system | Testing Method |
Specific Gravity | 1.53 | g/cm³ | ASTM D792 |
Specific volume | 0.658 | cm³/g | ASTM D792 |
Shrinkage rate | Internal Method | ||
Flowing 3 | 0.30 to 0.50 | % | |
Flowing 4 | $0.50 to $0.80 | % | |
Lateral Flow 3 | 0.40 to 0.60 | % | |
Horizontal Flow 5 | $0.60 to $0.90 | % | |
Absorption rate (24 hr) | 0.060 | % | ASTM D570 |
| Hardness | Rated Value | Unit system | Testing Method |
Rockwell Hardness (R Scale) | 118 | ASTM D785 |
| Mechanical properties | Rated Value | Unit System | Testing Method |
Tensile strength 6 (Break) | 119 | MPa | ASTM D638 |
Elongation 6 (Break) | 3.0 | % | ASTM D638 |
Bend Modulus 7 (50.0 mm Span) | 7580 | MPa | ASTM D790 |
Bend Strength 7 (Break, 50.0 mm Span) | 190 | MPa | ASTM D790 |
| Impact Resistance | Rated value | Unit system | Testing Method |
Overhanging beam notch impact strength (23°C) | 85 | J/m | ASTM D256 |
Gap-free cantilever beam impact (23°C) | 800 | J/m | ASTM D4812 |
| Thermal performance | Rated Value | Unit System | Testing Method |
Hot Deformation Temperature | ASTM D648 | ||
0.45 MPa, annealed, 6.40 mm | 216 | °C | |
1.8 MPa, as-annealed, 6.40 mm | 207 | °C | |
Linear Coefficient of Thermal Expansion - Flow | ASTM E831 | ||
-40 to 40°C | 2.5E-5 | cm/cm/°C | |
60 to 138°C | 2.5E-5 | cm/cm/°C | |
RTI Elec | 140 | °C | UL 746 |
RTI Imp | 140 | °C | UL 746 |
RTI Str | 140 | °C | UL 746 |
