Stability and Degradation

The degradation reactions of polymers have been widely reviewed 525). In the absence of air, thermal reactions are the important degradation route. They may involve reactions of functional groups on the chain without chain scission, typified for example by the dehydrochlorination of PVC, or reactions involving chain scission, often followed by depropagation and chain-transfer reactions to yield complex mixtures of products. This latter route would be typical of the degradation of poly(methyl methacrylate), which depolymerizes smoothly to its monomer, and of polystyrene, which produces a wide range of tarry products. 

In spite of the obvious importance of polymer stability in any potential applications of conducting polymers, there have been remarkably few systematic studies of degradation of polymers other than polyacetylene. Partly this may be due to an understandable reluctance of those involved in research on these materials to find that they are not stable and partly it is due to the difficulty of preparing samples in appropriate film forms for study. Another problem of discussing stability in conducting polymers is that there is no absolute standard for a stable material. For some applications an 

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Kyker GS, Valaitis JK (1978) In Allara DL, Hawkins WL (eds) Stabilization and degradation of polymers. Advances in chemistry series, USA, chap 24,169 293... 

Considering the high hydrophobicity of the palmitoyl side chain and the rigidity of the polymer backbone, we assumed that poly(N-palmitoylhydroxyproline ester) would degrade somewhat more slowly than poly (lactic acid) or polycaprolactone. In order to confirm this hypothesis, a series of long-term stability and degradation studies have been performed over the last 2 years at MIT (22). 

Kyker, G. S. and Valaitis, J. K., in "Stabilization and Degradation of Polymers," Advances in Chemistry Series 169, American Chemistry Society, Washington, D.C., 1978. 

R. D. Shupe and T. D. Baugh. Thermal stability and degradation mechanism of alkylbenzene sulfonates in alkaline media. J Colloid Interface Sci, 145(l) 235-254, August 1991. 

R.L. Gray and C. Neri, Proceedings 19th Ann. Inti. Conference on Advances in the Stabilization and Degradation of Polymers, Luzern (1997), pp. 63-79. 

PP Klemchuk (ed.), Polymer Stabilization and Degradation. ACS Symposium Series 280. Washington, D.C. American Chemical Society, 1985. 

Y. Nabuchi, E. Fujiwara, H. Kuboniwa, Y. Asoh, H. Ushio, The Stability and Degradation Pathway of Recombinant Human Parathyroid Hormone Deamidation of Asparaginyl Residue and Peptide Bond Cleavage at Aspartyl and Asparaginyl Residues , Pharm. Res. 1997, 14, 1685-1690. 

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