演題概要

オーラルセッション

第3日 5月20日(金) 10:00~10:20 B会場(星雲1)

A full analytical strategy for the characterization of ethylene vinyl acetate copolymers and their degradation products under thermal and hydrolytic ageing

(AIST)
oFouquet, ThierrySato, Hiroaki

Ethylene vinyl acetate copolymers (EVA) are first class industrial polymers whose applications range from adhesives to padding and packaging to photovoltaics as encapsulants for solar cells. Numerous articles deal with thermal analyses, NMR or FTIR spectroscopies for EVA while mass spectrometry (MS) with soft ionization – a valuable analytical tool for polymers – has surprisingly not been used so far.
Here is proposed a complete analytical strategy relying on the use of size exclusion chromatography coupled with matrix assisted laser desorption ionization (MALDI) high resolution mass spectrometry to thoroughly characterize intact EVA oligomers. In particular, the nature of the end-groups and the VA content of commercial samples are successfully evaluated for the shortest chains (found to be representative of the whole sample according to NMR) from both the raw SEC-MS data and after a Kendrick mass defect analysis (KMD). Based on this satisfactory background, a similar strategy is applied to gain further insights into the composition of Soxhlet-extracted chains from crosslinked EVA sheets as well as partially hydrolyzed EVA (formed upon an in-vial hydrolytic degradation of SEC-fractionated EVA producing ethylene vinyl acetate vinyl alcohol terpolymers) and thermally degraded EVA - both constituting meaningful models for the degradation routes undergone by technical products.