• 공업화학
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• 제2권3호
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• pp.199-208
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• 1991

양이온 중합은 electron이 풍부한 단량체들을 중합하는데 널리 이용되나 많은 부 반응과 빠른 중합속도 때문에 반응을 제어하기가 어렵다. 최근에 이러한 반응 제어에 많은 연구가 되고 있는데 특히 living 중합에 의하여 중합반응을 제어하는 방법에 대한 연구가 활발하다. 본고에서는 종합활성점의 해리상태를 조절하여 중합반응을 제어하고 living 중합을 도모하는 방법에 대하여 기술하였다. 그리고 현재까지 알려진 여러 방법들을 이러한 기본원리하에서 설명하였다.

• 폴리머
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• 제32권4호
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• pp.366-371
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• 2008

The controlled/living cationic polymerization of $\alpha$-methylstyrene (${\alpha}MeSt$) and sequential block copolymerization of isobutylene (IB) with ${\alpha}MeSt$ were achieved using 2-chloro-2,4,4-trimethylpentane (TMPCl)/titanium tetrachloride ($TiCl_4$)/titanium isopropoxide ($Ti(OiPr)_4$)/2,6-ditert-butylpyridine (DtBP) initiating system in $CH_3Cl$/hexane(50/50 v/v) solvent mixture at $-80^{\circ}C$. The polymerization rate decreased with increasing $[Ti(OiPr)_4]/[TiCl_4]$ ratio in the homopolymerization of ${\alpha}MeSt$. The effects of $[Ti(OiPr)_4]/[TiCl_4]$ ratios and $PIB^+$ molecular weight on the polymerization rate and blocking efficiency were also investigated. Well-defined poly(isobutylene-b-$\alpha$-methylstyrene)s were demonstrated by $^1H$-NMR and triple detection SEC; refractive index (RI), multiangle laser light scattering (MALLS) and ultraviolet (UV) detectors. Blocking efficiencies for the poly(isobutylene-b-$\alpha$-methylstyrene)s of almost 100% were obtained when ${\alpha}MeSt$ was induced by PIB's of $M_n\;{\geq}\;41000$ at $[Ti(OiPr)_4]/[TiCl_4]=1$. Differential scanning calorimetry (DSC) of the block copolymers showed two glass transition temperatures, thereby demonstrating microphase separation.