Glycolic acid, radiation effect

Aliphatic Poly St rs. Over the past 10 years the linear aliphatic polyesters, the polyalkanoates, and the copolymers of lactic and glycolic acids have attracted enormous interest as a result of their widespread use as biomedical materials. The radiation stability of these materials is of importance because of the potential to effect sterilization through exposure to ionizing radiation (215-225). 

The results of Babanalbandi and co-workers (221), in which new aliphatic chains ends formed by cleavage of the main chain at the ester unit are observed, are in support of a mechanism in which chain scission dominates cross-linking. These authors reported G-values for the formation of chain end structures comparable with earlier study. Furthermore, the main volatile products of radiolysis of PLA and poly(glycolic acid) (GPA) are CO2 and CO, consistent with chain scission being the most important reaction. In addition, small amounts of hydrogen and ethane gas were observed on the radiolysis of PLA. Finally, Montanari and co-workers (226) have examined the effects of radiation sterilization on the stability of PLGA microparticles used for drug delivery. 

The indirect action of radiation on aqueous alcohol leads to changes which are broadly similar in pattern to the direct-action effects described for pure alcohols. Hydrogen, aldehydes, glycols, and acids are formed in general, although it has not been established that acids are primary products. ... 

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