Terpene-based semi-interpenetrating polymer networks initiated by p-nitrobenzyl triphenyl phosphonium ylide: synthesis and characterization

Abstract

A series of semi-interpenetrating polymer networks (IPNs) based on poly(α-terpineol-costyrene) and ethylacrylate cross-linked with divinyl benzene have been synthesized at 80 • C for 80 min in dioxane, initiated by p-nitrobenzyl triphenyl phosphonium ylide, under an inert atmosphere of nitrogen. The Fourier transform infrared spectrum attributes structural evidences for IPNs, indicating characteristic frequencies of the ester group of ethyl acrylate at 1727 cm −1 and alcoholic group of α-terpineol at 3390 cm −1 . The percentage swelling and average molecular weight between crosslinks (m c ) are a direct function of α-terpineol-co-styrene and p-nitrobenzyl triphenyl phosphonium ylide and inverse function of ethyl acrylate and divinylbenzene. The semi-IPN system is confirmed by two T g values from the differential scanning calorimetry scan at 15 and 59 • C. SEM micrographs show phase separation. The thermogravimetric analysis (TGA) curve shows the IPN to be thermally stable. From the TGA curve the activation energy is calculated using the Coats and Redfern equation to be 23 kJ/mol.