Synthesis and properties of benzalmalonate polymer

Abstract

In this work, poly (diethylbenzal malonate vinyl ether) was synthesized from diethylbenzal malonate vinyl ether monomer via free radical polymerization. The diethylbenzal malonate vinyl ether monomer was obtained from dehydrobromination of 4-((2-bromo) ethoxy) benzaldehyde which was the product from nucleophilic substitution reaction between 4-hydroxybenzaldehyde and 1,2-dibromoethane. The synthesized oligomer possesses UVB absorption property and showed excellent solubilities in most organic solvents. Photostability test indicated that the oligomer was more photostable than the commonly used UVB filter, octyl methoxycinnamte. In addition to the preparation of poly (diethylbenzal malonate vinyl ether), in this work, grafting of the UVA-B chromophore 2,4,5-trimethoxycinnamic acid onto polyvinyl alcohol (PVA) was also done. The poly [(vinyl 2,4,5-trimethoxycinnamate) (vinyl alcohol)] copolymer showed UVA-B absorption property. Its UV absorption spectrum was similar to that of the grafted chromophore. Moreover, the grafted polymer showed better solubility in organic solvents comparing to PVA. However, the poly [(vinyl 2,4,5-trimethoxycinnamate) (vinyl alcohol)] copolymer showed less photostability comparing to the free chromophore.