COMPOSTABILITY OF CELLULOSE-ACETATE FILMS

Composting is an accelerated biological decay process viewed by many t o be a potential solution to the solid-waste management crisis existin g in many parts of the world. As part of a program to develop environm entally nonpersistent polymers that are compatible with a composting e nvironment, we have developed a bench-scale compost methodology that e mulates a high efficiency municipal windrow composting operation. A se ries of cellulose acetate films, differing in degree of substitution, were evaluated in this bench-scale system. In addition, commercially a vailable biodegradable polymers such as poly (hydroxybutyrate-co-valer ate) (PHBV) and polycaprolactone (PCL) were included as points of refe rence. 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 remo ved preferentially from the more highly substituted and slower degradi ng cellulose acetates. (C) 1994 John Wiley & Sons, Inc.