Thermal degradation behaviour of poly(oxymethylene): 1. Degradation and stabilizer consumption

The influence of molecular weight on the properties of polyacetal/hydroxyapatite nanocomposites. Part 2. In vitro assessment

“…Generally, the POM thermal stability decreases with a decrease of molecular weight: this effect can be attributed to the higher concentration of end groups in the POM matrix with low molecular weight (especially in T4 copolymer). It is understood that POM degradation is initiated either by bond dissociation at the chain end (-OH groups), or by random main-chain scission for the end-capped polymer followed by unzipping [29,30]. If the hydroxylic groups of POM are not blocked, rapid depolymerization takes place at moderate temperatures by a zipper mechanism yielding the monomer again [31].…”

Review on the thermo-oxidative degradation of polymers during processing and in service

“…The long term heat degradation of polyacetals is a combined process of oxidation and acidolysis [144][145][146][147]. In first instance polyacetals oxidizes according to the mechanism shown in Scheme 1, with the oxidation taking place at the methylene groups.…”

Polyoxymethylene Additives

“…At moderate temperature, when evaporation plays a negligible role, SE is very close for all stabilizers under study. This militates in favor of a very close k S1 value for all the members of the hindered phenol family, as suggested by Gur'yanova et al [13] who calculated a rate constants ratio characterizing the stabilizer efficiency k S1 ²/k 6 . It seemed to us interesting to compare k S1 with k 3 , having in mind that:…”

“…During thermo-oxidative aging, stabilizers are continuously consumed as monitored for example by Differential Scanning Calorimetry (DSC) under oxygen [5,6]. When concentration becomes negligible, the oxidation mechanism occurs as in a pure polymer.…”