STUDY ON THE COURSE OF BIODEGRADATION OF PVC/CELLULOSE COMPOSITES

摘要

On the basis of literature data the effects of external factors(oxygen presence,pH of environment,temperature)and internal ones(chemical structures of macromolecules,crystallization degree,physical state of material)on the course of biodegradation process of polymer in natural conditions were discussed.Poly(vinyl chloride)/cellulose composites,with cellulose part 25,50 or 75 wt.%(Table 1),were obtained by pouring out from solutions.The samples obtained were stored in forest soil for 6 months.During biodegradation,pH of soil was measured(Table 2)and samples'biodegradation degree(B)was evaluated(Fig.4)on the basis of respiration analysis.Thermal stability change(Fig.3,6-8,Table 3)caused by biodegradation was studied by thermogravimetric method.The sample structures were observed using optical microscopy(Fig.1 and 2)and by atomic force microscopy(AFM)(Fig.5).It was found that biodegradation of PVC/cellulose composites depended on polysaccharide content and was more effective than PVC itself while dehydrochlorination,characteristic for PVC,was inhibited in the presence of natural polymer.Probable crosslinking among the molecules of both polymeric components in the composites improved thermal stability of the samples degraded.