Frontal polymerization (FP) is a mode converting a monomer into a polymer via a localized reaction zone that propagates through the monomer. Frontal polymerization is a novel polymerization means, rapid reaction speed, high energy efficiency, less pollution and easier reaction process controllability are its remarkable advantages.There are three types of frontal polymerization:first, thermal frontal polymerization (TFP), which uses an external energy source to initiate the front; second, photofrontal polymerization, in which the localized reaction is driven by an external UV source; third, isothermal frontal polymerization, which relies on the Norrish-Trommsdorff or gel effect, which occurs when the monomer and initiator diffuse into a polymer seed (small piece of polymer).In this study, we used TDI and PPG to prepare PU via frontal polymerization. Through the study of polyurethane reaction, we found the relationship between frontal polymerization velocity and Tmax with the amount of catalysts. And the effect of proportion of DBTDL/TDI on frontal polymerization velocity with the molecule weight of PPG was also studied.Using DBTDL with TDI in 0.010-0.014 mole rate between front polymerization, there will not to be have tradition polymerization. When DBTDL with TDI over 0.014 proportion than the reaction rate will rise sharply, so, tradition polymerization has happened since the polymerization reaction.The increasing use of solvent will reduce the monomer and catalyst concentration, the activity of reaction system will reduce too. At the same time, surrounding heat dissipating increased, thus Tmax will reduce, and frontal polymerization velocity decreases.FT-IR demonstrated that, PU synthesized by frontal polymerization shares the same characteristic peak with PU which was synthesized by batch polymerization. Good PU dispersion was observed in SEM pictures. Comparing thermal and mechanical properties of batch polymerization and frontal polymerization, we found that the latter has a superior performance. |