Synthesis of novel methacrylic polymers by group transfer polymerization

Abstract

In the first thesis, cyclopolymerization of bis(2-carbomethoxyallyl) methylamine(DCMA) by group transfer polymerization(GTP) was investigated. A new difunctional methacrylate monomer. DCMA was synthesied from the reaction of methyl 2-chloromethylacrylate and methylamine. the polymerization of DCMA could be initiated by a silyl ketene acetal in the presence of a nucleophilic catalyst, and yielded a cyclopolymer without any cross-linked product. Poly(DCMA) prepared by GTP was soluble in organic solvent, and the 1H-NMR, 13C-NMR, and IR spectra of poly (DCMA) showed no vinyl peaks. Thus the complete cyclopolymerization was proved. From the 13C-NMR spectra of poly(DCMA), it was proved that the polymer had tacticity of syndiotactic(rr) and heterotactic(mr) component. The mechanism of cyclopolymerization by GTP was proposed using nondissosiative mechanistic rationale, as intermolecularintramolecular mechanisms. The polymerization proceede at room temperature and the polymerization yield was quantitative. The polydispersities of poly(DCMA) obtained by GTP were estimated to be in 1.31 to 1.32 range. On the other hand, radical polymerization of DCMA gave the polymer of broad molecular weighf distribution($\underline{M}$w/$\underline{M}$n=3.70). This fact indicates that GTP of DCMA is a living cyclopolymerization which has not been investigated yet. By using living characters of this cyclopolymerization, the block copolymers consisting of cyclopolymer and poly(alkyl methacrylate) segment could be prepared. The polydispersities of these AB and ABA block copolymers were in 1.40 to 1.52 range. By 1H-NMR, GPC and solvent extraction experiment, formation of the block copolymers were confirmed. In a TGA experiment of poly(DCMA) obtained by GTP, 95\% of initial weight remained at 310$^\circ$C, which reduced to 15\% at 420$^\circ$C. The DSC of poly(DCMA) showed a Tg at 140$^\circ$C It is expected that poly(DCMA) can be used as a reactive polymer capable of introducing functional ...