Influence of diethyl zinc on ethylene-norbornene copolymerization
محل انتشار: فصلنامه پلی اولفین ها، دوره: 5، شماره: 1
سال انتشار: 1396
نوع سند: مقاله ژورنالی
زبان: انگلیسی
مشاهده: 382
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شناسه ملی سند علمی:
JR_POJ-5-1_007
تاریخ نمایه سازی: 15 اردیبهشت 1397
چکیده مقاله:
Ethylene-norbornene copolymers were synthesized with a homogeneous catalyst system based on bis(imino) pyridine iron with the addition of diethyl zinc (DEZ) as alkyd transfer agent to promote immortal copolymerization. The addition of DEZ did not influence the catalytic activity in copolymerization with 7.5 mmol of norbornene (NB), but in the reactions with 70 mmol, the comonomer promoted an increase of activity. We observed by thermal analysis that the norbornene inserted in the chains promoted an increase in thermal stability of the synthesized material with higher amounts of comonomer, since the temperature of initial degradation was much higher for these copolymers compared to polyethylene. In addition, for the copolymers with 7.5 mmol of norbornene, the DEZ served as alkyd transfer agent, as shown by the gel permeation chromatography analysis, leading to a decrease in both molar mass and polydispersity. The UV-Vis spectra showed that the diethyl zinc did not change the catalytically active center, but only acted as an alkyd transfer agent. Polyolefins J (2018) 5: 71-84
کلیدواژه ها:
نویسندگان
Leticia Quinello Pereira
Universidade Federal do Rio de Janeiro, Instituto de Macromoléculas Professora Eloisa Mano-IMA-UFRJ
Maria de Fátima Vieira Marques
Av. Horácio Macedo, ۲۰۳۰, Centro de Tecnologia Bloco J. Cidade Universitária. Rio de Janeiro, RJ, Brazil