Radiation-induced reactions with cellulose. VIII. Effect of additives on copolymerization with styrene using the simultaneous technique

Abstract

The effect of additives upon the grafting of styrene to cellulose has been studied for the system cellulose-styrene-methanol irradiated in air at dose-rates ranging from 0.045-0.77 Mrad/hr in a cobalt-60 facility. The additives included glycol, acetic acid, ethyl acetate, chloroform, acetone, aniline, benzaldehyde, hydroquinone, thiourea, thiophen, pyridine, benzene, naphthalene, pyrene, phenanthrene, durene, hexamethylbenzene, stilbene, acridine, and fluoro-, chloro-and bromo-benzene. At a low concentration (10^-2M) of the non-aromatic additives, a reduction in grafting yields is observed whereas at a higher concentration (10^-1M) of the same additives sensitization is common. Radical scavengers such as hydroquinone and thiourea suppress grafting provided their concentration in the grafting solution is sufficiently high. With the aromatic additives, little change in grafting yields is observed except for anthracene and acridine. Possible reaction mechanisms are discussed. Preliminary studies are also reported for the effect on grafting of chemically bound lignin and non-cellulosic material present in the trunk polymer.