Dual-Cure Coatings: Spiroorthoesters as Volume-Controlling Additives in Thiol–Ene Reactions

Philipp Marx, Angelo Romano, Roland Fischer, Ignazio Roppolo, Marco Sangermano, Frank Wiesbrock

Publikation: Beitrag in FachzeitschriftArtikelForschungBegutachtung

6 Zitate (Scopus)


Most thiol–ene systems exhibit shrinkage during cross-linking, potentially resulting in micro-cracks and delamination. Oligocyclic monomers like spiroorthoesters (SOEs), on the contrary, show expansion during the ring-opening polymerization. In this communication, a photocurable thiol–ene system composed of a trifunctional thiol, a bisfunctional allyl-bisphenol A compound, and an SOE compound bearing one olefin function shows expansion in the range from −3.07 to +1.70 vol% if the SOE content is increased from 0–30 wt%. Network formation can be accomplished under visible light if a radical as well as a cationic photoinitiator (dual-cure mechanism) and a sensitizer are used. The elasticity of the cured resin increases upon the addition of the SOE; correspondingly, the glass-transition temperature shows a (minor) decrease from 16 to 3 °C. A tailor-made combination of the allyl-bisphenol A compound (90 wt%) and the SOE (10 wt%) yields networks that are volume-neutral during curing.
FachzeitschriftMacromolecular materials and engineering
Frühes Online-Datum18 Jan. 2019
PublikationsstatusVeröffentlicht - Apr. 2019

Bibliographische Notiz

Funding Information:
P.M. and A.R. share the first authorship. The research work was performed within the K-Project PolyTherm at the Polymer Competence Center Leoben GmbH (PCCL, Austria) within the framework of the COMET-program of the Federal Ministry for Transport, Innovation and Technology and the Federal Ministry for Digital and Economic Affairs in collaboration with the Politecnico di Torino, the Montanuniversitaet Leoben, and the Graz University of Technology. Funding was provided by the Austrian Government and the State Government of Styria.

Publisher Copyright:
© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

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