Photo-polymerizable, low shrinking modular construction kit with high efficiency based on vinylcyclopropanes

Abstract

The successful development of a universal hydrogen bond (H-bond) concept, specific for bi-functional vinylcyclopropane (VCP) ester–amide derivatives is reported here. Thereby, uniformity within the intermolecular hydrogen bond strength as investigated by variable temperature NMR and FT-IR measurements provides an excellent control of high reactivity, nearly regardless of the chosen spacer-unit, offering the system a possible application as a modular construction kit for cross-linked networks with varied properties. Two entirely diversified VCP ester–amide systems were prepared. The performance benchmark of a flexible, high molar mass macro-monomer VCPPPG₂₀₀₀, implementing a polypropyleneglycol Genamine D01/2000 macro-spacer, and two rigid, low molar mass monomers VCP-m-phenyl and VCP-p-phenyl outlined significantly the strength of the system. Extremely low volume shrinkages between 1.4–4.5% and a wide range of E-moduli could be achieved. An easy control of adjusting final characteristics by varying the co-monomer content in co-networks was shown, especially without obtaining any significant disadvantage in the curing behavior. The VCP ester–amides offer the possibility to replace some currently used dimethacrylate resins within several high-end applications, especially where low volume shrinkage and high polymerization efficiency are required.