Epoxide-functionalized hyperbranched polyethylene and its applications in functional polymer synthesis and hot lithography photopolymer toughening

Abstract

The copolymerization behaviour of four epoxide-containing ene-functionalized monomers with ethene using palladium α-diimine catalyst was investigated. The linker separating oxirane and double bond played a crucial role in the process. High molar mass copolymers of ethene rich in glycidyl 10-undecenoate were obtained without a significant loss of catalyst activity. Allyl glycidyl ether was able to form copolymers with high comonomer incorporation as well, however, the copolymer molar mass and catalyst activity decreased severely. Therefore, we tuned the reaction conditions in order to achieve a better compromise between comonomer incorporation and product molar mass. Adjustments of reaction temperature, ethene pressure and used solvent were shown to impact the copolymer properties. Furthermore, the prepared copolymers were used in subsequent post-polymerization modifications. We have demonstrated that despite the steric hinderance of the polymer chain, pendent epoxide rings can be reacted with acids, O, C, N and Snucleophiles quantitatively to prepare hyperbranched molecules with a diverse range of functional groups. Finally, the prepared epoxide-functionalized hyperbranched polyethylene was tested as rubber toughening agent of brittle photopolymers revealing its potential for hot lithography 3D printing.