메탈로센 촉매를 이용한 poly(ethylene-ter-high α-olefin-ter-divinylbenzene) TPE 중합에 관한 연구

Abstract

Researches on polymerization using metallocene catalysts began with the identification of the structure of ferrocene by Wilkins and Fischer in 1952, and was further developed by Kaminsky in the 1980s.1-3 Polymerization using metallocene catalyst, possible to synthesis the copolymers which have narrow molecular weight distributions, high stereo-regularity, and uniform comonomer incorporation.4-6 In this study, we prepared poly(ethylene-ter-1-hexene-ter-divinylbenzene) using various metallocene catalyst such as rac-Et(Ind)2ZrCl2 (C1), rac-SiMe2(Ind)2ZrCl2 (C2), and rac-SiMe2(2-Me-Ind)2ZrCl2 (C3) with trityl tetrakis(pentafluorophenyl)borate/triisobutylaluminium cocatalysts system. Consequently, C1 and cocatalyst system showed the highest catalytic activity and weight averaged molecular weight around 143,000 g/mol. After then we investigated characteristic changes according to input of high α-olefin which has different chain length and the divinylbenzene (DVB) input. Each of prepared sample named to poly(ethylene-ter-1-hexene-ter-divinylbenzene), poly(ethylene-ter-1-octene-ter-divinylbenzene), poly(ethylene-ter-1-decene-ter-divinylbenzene, poly(ethylene-ter-1-dodecene-ter-divinylbenzene). Each of the synthesized terpolymer were named to PHEV, PEOV, PEDV, and PEDDV. "Comonomer effect", catalytic activity, molecular weight, and molecular weight distribution of the terpolymers were investigated. For the supplementary study, we optimized polymerization system for PEDV with varying polymerization parameters such as polymerization temperature, polymerization time, Al/Ti input ratio, B/Ti input ratio, and catalyst content. The optimized conditions of copolymer were investigated with Al/Ti, B/Ti, catalyst amount, polymerization temperature, and polymerization time were 500, 1.5, 2.5 µmol, 50℃, and 20 min, respectively. Additionally, we prepared PEDV-g-styrenic monomers) by graft copolymerization of styrenic monomers to PEDV. And we confirmed the structure and thermal property of prepared polymer by 1H-NMR and DSC.