Comparison of photo degradation behavior of LDPE using accelerated weathering instruments

摘要

Samples of low-density polyethylene (LDPE) were photodegraded using accelerated weathering instruments and outdoor exposure. The physical properties and chemical structures of the photodegraded samples were studied through a tensile test, gel chromatography, and infrared spectroscopy. The molecular weight distribution of a photodegraded sample by using a fluorescent UV lamp at a high black panel temperature (80°C) was more similar to that of an outdoor-degraded sample than that of other artificially photodegraded samples by using a Xenon lamp at the standard black panel temperature (63°C). It is estimated that accelerated weathering tests at a high sample temperature could accelerate cross-linking than chain scission, consequently recreating moleculeenlargement similar to the outdoor-degraded sample.