• Fibers and Polymers
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• v.5 no.4
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• pp.253-258
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• 2004

Living nature of photoinduced cationic polymerization of isobutyl vinyl ether (IBVE) in the presence of various combinations of diphenyliodonium halide (DPIX), a photocationic initiator and zinc halide $(ZnX_2)$ in methylene chloride has been investigated. Attainment of $100\%$ conversion and a linear relationship between $\%$conversion and number average molar mass of the resulting polymer, strongly suggests the living nature of this system. Livingness of the polymerization system was observed irrespective to the type of halide anion of the initiator and zinc salts unless the reaction temperature is not higher than $-30^{\circ}C$. The rate of polymerization decreases in the order of iodide > bromide > chloride when halide salt of DPIX and $ZnX_2$ are used. It is postulated that the cationic initiation is started by the insertion of weakly basic monomer in to the activated C-X terminal of the monomer adduct which is a reaction product of monomer and HX, a photolytic product of DPIX, formed in situ during the photo-irradiation process. It was concluded that polymerization is initiated by the insertion of weakly basic monomer into activated C- X terminal of monomer adduct due to the pulling action of$ZnX_2$, which successively producing a new polarized C-X terminal for the propagation in cationic nature. This led us to a conclusion that the living nature of this cationic polymerization is ascribable to the polarized C-X growing terminal, which is stable enough to depress the processes of chain transfer or termination process.

• Fibers and Polymers
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• v.1 no.1
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• pp.1-5
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• 2000

Poly(3-methyltetrahydrofuran)(3-MTHF) and poly(tetrahydrofuran-co-3-MTHF), having very narrow molecular weight distribution were successfully synthesized via photo-induced living cationic polymerization in the presence of diphenyliodonium hexafluorophosphate. Linear relationship between % conversion and number average molecular weight of resulting poly(3-MTHF) in the polymerization of 3-MTHF, carried out at -22$^{\circ}C$, indicates that the 5-membered cyclic oxonium ion, being responsible for the cationic propagation is stabilized by ion pall formation with hexafluorophosphate anion, supplied from the salt. The linear relationship between two parameters, mentioned above was also observed in the copolymerization of 3-MTHF with THF, carried out at 0 and -22$^{\circ}C$. The molecular structures including the copolymer composition and average molecular weight and its distribution is determined by reaction parameters such as monomer feed ratio and reaction temperature.

• Proceedings of the Korean Fiber Society Conference
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• 2001.04a
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• pp.31-34
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• 2001

• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.223-226
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• 2001

비닐에테르류의 비닐단량체는 ZnI$_2$ 존재하에서 HI와 같은 프로톤 산에 의해 양이온 리빙중합이 가능함이 보고된 바 있는데 이 때 프로톤산은 비닐에테르 단량체와 반응하여 adduct를 생성하고, ZnI$_2$는 adduct의 양이온중합 활성화제로 작용하는 것으로 알려져 있다. (중략)