Photopolymerization of vinyl-containing liquid silizane preceramic monomers copolymerized with thiol monomers, based on a step-growth radical polymerization mechanism, is a novel, rapid, inexpensive and simple technique for producing preceramic structures from liquid precursors. The kinetics of alkyl 3-mercptopropionate-vinyl silizane under UV irradiation is investigated by using realtime Fourier transform infrared (FT-IR) and photo-differential scanning calorimetry (photo-DSC). The experimental results show preliminarily that: (1) about 80% conversion of vinyl group has been achieved in the presence of a low concentration photoinitiator under UV irradiation; (2) by increasing the functionalities of the thiol group, the peak rate of copolymerization increases and the final conversion of the vinyl group decreases; (3) the copolymerization is primarily a bimolecular radical termination process; (4) the copolymerization is first-order, i.e., its rate is proportional to the vinyl group concentration and independent of the concentration of thiol group.

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Abstract. The curing reaction characteristics of modified amine-epoxy and epoxy asphalt system under different heating rates were analyzed by differential scanning calorimetry (DSC). The relationship between curing degree and activation energy during the curing reaction is studied. The Kissinger equation was used to calculate the apparent activation energy of the reaction, and the rate constant and the reaction order of the curing reaction were fitted by Kamal equation. The results showed that the curing reaction was a typical self-catalytic reaction, the apparent activation energy of epoxy system and epoxy asphalt system were 34.95 kJ/mol and 42.02 kJ/mol, respectively. Meanwhile the curing reaction rate constant and order of the epoxy asphalt system were less than those of the epoxy system. The curing reaction rate of epoxy curing system was contracted by introduced asphalt. Furthermore, the late of curing reaction was dominated by diffusion control.