What are the differences in thermal expansion coefficients between plastic types?

Thermal expansion coefficients vary significantly among different plastic types, influencing their suitability for specific applications. Generally, thermoplastics like polyethylene (PE) and polypropylene (PP) exhibit higher coefficients, meaning they expand more under heat compared to engineering plastics such as polycarbonate (PC) or acrylonitrile butadiene styrene (ABS). For instance, PE has a thermal expansion coefficient of around 200 x 10^-6 /°C, while ABS ranges between 60-100 x 10^-6 /°C.

Factors like polymer structure, crystallinity, and additives also play a role. Amorphous plastics (e.g., polystyrene) typically expand less than semi-crystalline ones (e.g., nylon). Understanding these differences is crucial for designing products that endure temperature fluctuations, ensuring dimensional stability and performance in industries like automotive, aerospace, and electronics.