COMPOSTABILITY OF CELLULOSE-ACETATE FILMS

Composting is an accelerated biological decay process viewed by many to be a potential solution to the solid-waste management crisis existing in many parts of the world. As part of a program to develop environmentally nonpersistent polymers that are compatible with a composting environment, we have developed a bench-scale compost methodology that emulates a high efficiency municipal windrow composting operation. A series of cellulose acetate films, differing in degree of substitution, were evaluated in this bench-scale system. In addition, commercially available biodegradable polymers such as poly (hydroxybutyrate-co-valerate) (PHBV) and polycaprolactone (PCL) were included as points of reference. Based on film disintegration and on film weight loss, cellulose acetates, having degrees of substitution less than approximately 2.20, compost at rates comparable to that of PHBV. NMR and GPC analyses of composted films indicate that low molecular weight fractions are removed preferentially from the more highly substituted and slower degrading cellulose acetates. (C) 1994 John Wiley & Sons, Inc.