ABIOTIC DEGRADATION PRODUCTS FROM ENHANCED ENVIRONMENTALLY DEGRADABLE POLYETHYLENE

Abiotic degradation products from LDPE with starch + pro-oxidant, LDPE with starch only and pure LDPE were determined as a step towards establishing products resulting from environmental degradation. The samples were subjected to thermal ageing in water at 95-degrees-C for 6 weeks or alternatively pre-heated and subsequently immersed in aqueous environments at ambient temperature for 10 months whereafter the water phase was analyzed for degradation products.Altogether over 50 degradation products were identified by GC-MS, mainly ketones, alcohols, aldehydes, lactones and carboxylic acids, the last being most represented. The amount of degradation products formed from the different samples correlated to their molecular weight reductions as measured by SEC but was also dependent on the permeability of the sample, i.e. its ability to allow formed degradation products to diffuse out to the surrounding environment. The addition of both starch and pro-oxidant significantly increased the susceptibility to degradation, while the addition of starch alone gave a noticeable but smaller increase.