Aliphatic polymers, degradation mechanisms

Kaspersma, J. Doumen, C. Munro, S. Prins, A. M. Fire retardant mechanism of aliphatic bromine compounds in polystyrene and polypropylene, Polymer Degradation and Stability, 2002, 77(2), 325-331. 

The study of the photochemistry of inorganic and organic compounds gives valuable information on their photolysis during which free radicals are formed (10-12). Extensive studies have especially been made in the field of photochemistry of aliphatic ketones,ethers and peroxides (12-14) All these compounds have been found to be good photoinitiators which initiate degradation and crosslinking of polymers. The mechanism of these reactions seems to be simples... 

What is the degradation mechanism for aliphatic-aromatic copolyesters, where aliphatic and aromatic structures are combined in one polymer chain ... 

Taniguchi I, Nakano S, Nakamura T, El-Salmawy A, Miyamoto M, Kimura Y (2002) Mechanism of enzymatic hydrolysis of poly(butylene succinate) and poly(butylene succinate-co-L-lactate) with a lipase from Pseudomonas cepacia. Macromol Biosci 2 447-455 Tomita K, Kuroki Y, Hayashi N, Komukai Y (2000) Isolation of a thermophile degrading poly(butylene succinate-co-butylene adipate). J Biosci Bioeng 90 350-352 Tserki V, Matzinos P, PavUdou E, Panayiotou C (2(X)6a) Biodegradable aliphatic polyesters. Part II. Synthesis and characterization of chain extended poly(butylene succinate-co-butylene adipate). Polym Degrad Stab 91 377-384... 

Bikiaris, D.N., Nianias, N.P., Karagiannidou, E.G., and Docoslis, A. (2012) Effect of different nanoparticles on the properties and enzymatic hydrolysis mechanism of aliphatic polyesters. Polym. Degrad. Stab., 97, 2077 -2089. 

Poly(ot-esters) are the earliest, most extensively studied, and commercially widely used bioresorbable polymers. Especially, the poly(a-hydroxy acids), including poly(glycolic acid) (PGA), stereoisomers of poly(lactic acid) (PLA) and their copolymers which have been extensively investigated for their degradation mechanisms and structure—property relationships [1—4]. Aliphatic polyesters based on poly(a-ester)s are discussed below. 

The comparison of the results obtained in this study for the LCP degradation imder processing temperatures with the peculiarities of some thermally stable polyheteroaiylenes degradation [14] brings to light some common features carbonization of the structure, H2 evolution, improvement in thermo-oxidative stability with transition metal compoimds. That is why we took into accoimt the stabilization of polysulfones, aiyl-aliphatic polyimides, polyamides etc. The approach to such stabilization is based on the following proposals on the mechanisms of the above said polymer degradation ... 

FTIR techniques in combination with or as complement to other measurement techniques have been used in a wide range of photochemistry studies on polymers. These include bisphenol-A polycarbonate [173], polycarbonate coatings on mirrors [174], PMMA [175], poly( -butyl acrylate) [176] and polypropylene [177]. DSC and FTIR studies have been used in conjunction to investigate the nature of y-radiation-induced degradation and its effect on the 19°C and 30°C phase transitions in PTFE [178]. IR studies of the hydrolysis of melamine-formaldehyde crosslinked acrylic copolymer films have shown that copolymer-melamine formaldehyde crosslinks are broken and that crosslinks between melamine molecules are formed [179]. The thermal and photo-degradation mechanisms in an IR study of cured epoxy resins were found to be related to the autoxidative degradation processes for aliphatic hydrocarbons [180]. 

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