SOLAR UV DEGRADATION PATTERNS IN PHOTODEGRADABLE LDPE

“Degradable” polymers have been proposed as an alternative to traditional polymers as a means to potentially reduce the amount and impacts of plastic marine debris, yet the degradation of these materials in seawater is typically unknown. The light-induced degradation of a copolymer of ethylene – carbon monoxide {1%} was studied under accelerated laboratory exposure conditions. The copolymer, used as a substitute for LDPE in some applications where rapid photodegradation is desirable, loses mechanical integrity and embrittles rapidly under outdoor exposure. A laboratory weathering study of these laminates was carried out to compare the kinetics of degradation on sand to those in seawater at ambient temperature, based on the rate of change in tensile properties of the material. Virgin resin pellets of the copolymer were also exposed to laboratory weathering to detect the generation of microparticles at their surface during extensive degradation. Microparticle generation, detected by laser light scattering, as a function of the exposure duration will also be discussed.