Emulsion Polymerization Of Methyl Methacrylate Initiated By Novel Initiator

The copolymer of a-methyl styrene (AMS) and maleic anhydride (MAn) was synthesized by self-stable precipitation polymerization. The resulting AMS-MAn oligomer was saponified and then served as macroinitiator and emulsifier for the further surfactant-free polymerization of methyl methacrylate (MMA). Surfactant-free emulsion polymerization of MMA was carried at 90℃. The results showed that the surfactant-free polymerization of MMA can be carried out by using saponified AMS-MAn oligomer, without any other initiator and emulsifier. Based on FTIR and 1H-NMR, the emulsion polymerization product was block copolymer of PMMA and AMS-MAn oligomer. During the process of surfactant-free polymerization of MMA, the polymerization rate increased along with the increasing of the concentration of macroinitiator. In addition, the intrinsic viscosity numbers of copolymers increased linearly with the rising of polymerization conversion. Based on the research results, the possible reaction mechanism has been proposed. This novel method is expected to be applied to kinds of other monomers.A novel initiator(TX-TX) was synthesized by the reductive coupling of carbonyl compounds:thioxanthone.The emulsion polymerization of MMA initiated by the novel initiator was carried out. The effects of temperature, initiator concentration and reaction time on monomer conversion, polymer molecular weight, microsphere size and size distribution were studied.