METHOD FOR ACCELERATED DEGRADATION OF THERMOPLASTICS

摘要

A method of determining degradation of a thermoplastic when exposed to light and heat includes illuminating the thermoplastic with a desired wavelength of light at a desired irradiance while maintaining the thermoplastic at a desired temperature. The method is useful to measure the discoloration rate of transparent, translucent and opaque thermoplastics such as polycarbonates, the discoloration rate being determined by transmission or reflectance spectra of transmitted or reflected white light through or from the thermoplastic.

主权项

1. A method for determining degradation of a thermoplastic, the method comprising:
illuminating the thermoplastic, for a period of time, with light having a peak intensity centered at a wavelength from about 400 nm to about 500 nm and an irradiance from about 400 W/m2 to about 150,000 W/m2; maintaining the average temperature of the thermoplastic at a temperature from about 23° C. to about 175° C. during the period of time; and repeating the illuminating and maintaining steps for a plurality of successive periods of time.