Photocrosslinking of a novel α,ω‐unsaturated copolyamide: mass spectrometric study on model compounds with benzophenone as photoinitiator

Abstract

The aim of this work was to understand the reactions involved in the photocrosslinking processes of a alpha,omega-unsaturated copolyamide foreseen as a new UV-curable powder coating. The crosslinking reaction was photoinitiated with benzophenone. In this paper, the photochemical reaction between benzophenone and several model compounds was investigated. The model compounds contained functional groups which could be present in copolyamide. The products resulting from UV curing were identified using a combination of high-resolution mass spectrometry and MS(n) experiments. The characterization of the products allowed localization of the hydrogen abstraction by the type II photoinitiator during UV curing and, consequently, the determination of the reactive sites of the unsaturated polyamide chain which were involved in the photochemical reaction.

1H NMR Study of Hydrogen Abstraction in Model Compound Mimics of Polymers

“…To simplify interpretation of the 1 H NMR spectra, we have chosen to study a series of model compounds with structures that mimic the repeat units of a number of commonly used polymers. The manner in which the structures of the model compounds map onto those of commonly used polymers is shown in Table . For instance, caprolactam ( 1 ) was used as a small molecule substitute for polycaprolactam, and ε ‐caprolactone ( 3 ) was used for polycaprolactone.…”