Properties of Plastics

• Tensile strength : COmpare to same weight ratios , it has higher strength than most metals . Howevers , the elasticity is lower . 
• Fire /heat : Thermoplastic soften at high temperature . And all plastic are combustible . 
• No treatment can be done to prevent plastic become non-combustible . However , if fire-retardant additives is added , some plastic can be very difficult to ignite . e.g. PVC . 
• Thermal Conductivity : Almost same as timber , which is comparatively low if compare to materials such as metal .
• Electrical Properties : Plastic are excellent insulators but electrostatic charges attract dust . 
• Thermal expansion  Generally , most of the plastics have several times expansion ability (Compare to steel ) while heat applied .
• Moisture Movement : Most plastic are resistant to water absorption  , and therefore do not exhibit moisture movement  . 
• Durability : Mostl of the plastic do not rot or corrode . Generaally , they have good resistance on chemical substance in building works . Ultra-violet (UV) from sunlight is the chief factors that causing plastic product to deteriorate .