ESR determination of rate constants for the radical polymerization of methyl phenethyl itaconate
ESR determination of rate constants for the radical polymerization of methyl phenethyl itaconate
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ESR 测定衣康酸甲酯苯乙酯自由基聚合速率常数
DOI：
10.1002/macp.1987.021881216
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发表时间：
1987
影响因子：
2.5
通讯作者：
T. Ota
中科院分区：
文献类型：
--
作者：
Tsuneyuki Sato;K. Morino;Hitoshi Tanaka;T. Ota
Phenethyl 2-(methoxycarbonylmethyl)acrylate (methyl penethyl itaconate) (1) was prepared and its polymerization with dimethyl 2,2′-azoisobutyrate (2) was investigated kinetically in benzene. The polymerization rate (Rp) was found to be expressed by Rp = k·[2]0,5·[1]1,8 (at 50°C). Further, a higher dependence of Rp (2nd order) on the concentration of 1 was observed at 61°C. The overall activation energy of the polymerization was calculated to be a low value of 50,3 kJ/mol. The initiator efficiency (f) of 2 was determined to be 0,48 to 0,22 at 50°Cand 0,50 to 0,28 at 61°C. f decreases with increasing monomer concentration due to the high viscosity of 1. The poly(1) radical is stable enough to be observable by ESR at high temperatures (50–60°C). Rate constants of propagation (kp) and termination (kt) were estimated using the poly(1) radical concentration determined by ESR. kp [6,0 to 121/(mol·s) at 50°Cand 7,1 to 15 1/(mol·s) at 61°C] shows a trend to increase with the concentration of 1. On the other hand, kt [2,9·104 to 17·1041/(mol·s) at 50°Cand 6,9·104 to 45·1041/(mol. s) at 61°C] decreases with increasing MPI concentration. This behavior is responsible for the high order with respect to monomer concentration. Copolymerization of 1 (M1) with styrene (M2) at 50°Cgave the following results: r1 = 0,36, r2 = 0,40, Q1 = 0,82 and e1 = + 0,59. Using the above results, the rate constants of the cross-propagations were estimated to be k12 = 22 1/(mol·s) and k21 = 308 1/(mol·s) at 50°C.
