Earticle

N-Methacryloyl-L-histidine and N-methacryloyl-L-histidine methyl ester were synthesized and polymerized to obtain polymeric catalysts with different functions. In the presence of each of these polymers the solvolytic reactions of p-nitrophenyl acetate (PNPA), 3-nitro-4-acetoxybenzoic acid(NABA), 3-acetoxy-N-trimethylanilinium iodide(ANTI) and 3-nitro-4-decanoyloxybenzoic acid(NDBA) were performed in 20% aqueous ethanol. For the purpose of comparison the low molecular weight analogs(LMWA's), L-histidine, L-histidine methyl ester and N-acetyl-L-histidine were also subjected to catalyze the solvolyses of above substrates. In the solvolysis of PNPA the polymeric catalysts exhibited lower activities than the LMWA's. However the ionic substrates, NABA and ANTI were solvolyzed at anomalous rate by polymeric catalyst, indicating that electrostatic effects are operative in the catalysis by polymers. Furthermore in the solvolysis of hydrophobic monomer NDBA, polymeric catalysts exhibited highly enhanced activities compared with the LMWA's implying that hydrophobic interaction can be the most important contribution to the high catalytic activity of imidazole-containing polymers.

이소시아네이트기를 말단기로 가진 SBR 프리폴리마를 금속 나트륨을 촉매로 사용하여 ${\varepsilon}$-카프로락탐과 함께 음이온 중합시켜 나일론 6-SBR-나일론 6 블록공중합체를 합성하였다. 촉매 농도의 변화는 반응에 큰 영향을 주지 않았으나 개시제인 SBR 프리폴리마의 농도는 0.5몰%일 때 가장 좋은 결과를 얻었다. 반응온도는 $150^{\circ}C$일 때에 비하여 $185^{\circ}C$일 때가 수득률과 분자량의 증가를 보였다. 합성된 중합체의 적외선 스펙트럼에서 $1,730 cm^{-1}$의 우레탄 카르보닐 흡수띠로부터 블록 공중합체임을 확인하였고 프리폴리마와 나일론의 특성 흡수띠에서의 흡광도비로부터 공중합체의 조성을 추정하였다.

Isocyanate-terminated SBR-prepolymers were prepared from SBR-diol and excess toluene diisocyanate. These prepolymers were then used as initiators for the sodium-catalyzed polymerization of ${\varepsilon}$-caprolactam. The resulting block copolymers, presumably the structure of nylon 6-SBR-nylon 6, were confirmed from their IR spectra. The viscosities of these polymers were measured in phenol/tetrachloroethane and the molecular weights were estimated. The polymerization reaction was not affected by the change in concentration of catalyst, but significantly faster at $185^{\circ}C$ than at $150^{\circ}C$. And the initiator concentration of 0.5 mole % gave good results.