Synthesis and Evaluation of Bifunctional Monomers Derived from Post-Industrial PET as Crosslinking Agents for Acrylic Monomers

Abstract

Two bifunctional monomers, bis (acryloxyethyl) terephthalate (BAOET) and bis (allyloxycarboniloxyethyl) terephthalate (BAOCOET), derived from PET waste were tested as crosslinking agents for acrylic and methacrylic acids (AA and MA, respectively). BAOET and BAOCOET were obtained from the reactions of acryloyl chloride and allyl chloroformate, respectively, with bis (hydroxyethyl) terephthalate (BHET). This was obtained from the glycolysis of postindustrial PET with ethyleneglycol (EG). Both bifunctional monomers were characterized by NMR 1H. Polymerizations of BAOET and BAOCOET with the acrylic monomers were performed using bifunctional monomer to acrylic monomer weight ratios of 1:10, 1:2 and 1:1, for each of the four combinations, using 2 wt % of benzoyl peroxide (BPO) as thermal initiator. The obtained gel proportions of the crosslinked polymers were above 90% for most of the cases, requiring times from 10 to 60 min. For all of the experiments, complete double bond conversion was observed by FT-IR. Polymers showed thermal stabilities higher than 200°C.