Molecular weights and molecular-weight distributions of cellulose and cellulose nitrates during ultrasonic and mechanical degradation

摘要

Cellulose and cellulose nitrate were subjected to depolymerization by ultrasonication and high-speed mechanical agitation (stirring). Both treatments resulted in significant, but different, depolymerization with the resulting degradation products having considerably narrower molecular weight distributions than the parent substrates. In all cases a level-off degree of polymerization was reached which was different for unsubstituted cellulose and the derivatives. The results obtained with unsubstituted cellulose are explained with the existence of "weak links" in cellulose backbones.