Degradable Polyethylene Film... The Facts, 1990 Polymers, Laminations & Coatings Conference Proceedings

With all the attention and enthusiasm over the “solid waste crisis,” there has been a significant effort to develop effective biodegradable additives in order to improve the biodegradability of polyethylene film. As a result of the public enthusiasm and emotion, much misinformation and deception abounds. Valuable work has been conducted in the past few decades which answers many of these guestions and current research is aimed at bringing more definition to this debate. The purpose of this analysis is to summarize the findings of other researchers as well as to present the results of a study conducted by the author in order to understand more about the activity of pro-oxidants and starch fillers in polyethylene film products. Commercially available starch masterbatches and prodegradant systems were utilized in monolayer blown film and coextruded cast film in an effort to understand the effects of the starch filler and pro-oxidant systems on physical properties, optical properties and oxidative degradation. Results would indicate that the pro-oxidant system currently utilized by ADM which consists of a transition metal salt and unsaturated polymer has a very significant effect on oxidative degradation at 160 degrees Fahrenheit for approximately 24 days. The starch filler is a significant processing constraint and results in various processing problems as well as compromised film properties. Previous research has revealed that molecular weight, crystallinity and the presence or absence of degradable additives can have a significant effect on polyethylene biodegradation.