Microbial degradation of polymer solids: Effect of pretreatments on degradability of cellophane

Specimens of regenerated cellulose films (cellophane) have been subjected to a pretreatment followed by microbial degradation. Pretreatments included mechanical deformation, acid hydrolysis, and alkaline degradation, and the subsequent fungal deterioration process was monitored by x-ray diffraction, infrared spectroscopy, and tensile property tests. Longitudinal prestraining of films, which produces small surface cracks, caused accelerated weakening due to action of cellulase enzymes; transverse prestraining of films, which produces internal reorganization but no surface cracks did not lead to any significant change in degradation rate. Nonenzymatic hydrolysis appeared to cause recrystallization of cellulose chain segments cleaved in disordered regions, and subsequent fungal degradation was found to remove these recrystallized regions preferentially.