Free-radical cross-linking copolymerization of methyl methacrylate and ethylene glycol dimethacrylate in the presence of trimethoxyvinylsilane

Abstract

Free-radical cross-linking copolymerization of methyl methacrylate (MMA), ethylene glycol dimethacrylate (EGDM), and trimethoxyvinylsilane (TMVS) has been investigated in toluene at a total monomer concentration of 4 mol L −1 and at 70 °C. Conversion of monomer, volume swelling ratio, weight fraction, and gel point were measured as a function of the reaction time, TMVS concentration, toluene content, temperature, and chain transfer agents up to the onset of macrogelation. Structural characteristics of the gels were examined by using equilibrium swelling in toluene, gel fraction, and Fourier transform infrared (FTIR) analysis. The morphology of the copolymers was also investigated by scanning electron microscopy (SEM). Based on the obtained results, it was concluded that the FTIR data did not have the capacity to show the presence of the TMVS moiety in these kinds of copolymers. On the other hand, the variation of weight fraction of gel, W g , and its equilibrium volume swelling ratio in toluene, q v , exhibited the same behaviors as that of MMA/EGDM copolymers. Also, the dilution of the monomer mixture resulted in an increase in the gel point and swelling degree and a decrease in the percent of conversion and gel fraction. Finally, TMVS is a suitable silicone co-monomer for this system and it has been proved useful.