羟基偶氮酯合成双端羟基聚苯乙烯动力学研究

采用偶氮二异丁腈、乙二醇为原料合成2,2-偶氮二异丁酸二(2-羟乙基)酯,并以此作为引发剂,合成双端羟基聚苯乙烯。利用死端聚合法测定了引发剂的引发效率,研究了聚合反应动力学,确定了在60℃下甲苯溶液中聚合反应的各种链转移常数值。结果表明,引发效率为0.76,引发活性较高;聚合速率Rp与单体浓度[M]和引发剂浓度[I]0.43成正比。计算出聚合反应表观活化能为75.3kJ/mol;引发剂链转移常数CI为0,溶剂链转移常数CS为1.94×10-3,60、80℃的Kp/Kt1/2值分别为2.26×10-2　(L/mol·s)1/2和3.78×10-2　(L/mol·s)1/2。

Kinetics Study of Dihydroxy- Terminal Polystyrene Using Hydroxy - Containing Azoester as an Initiator

The di(2-hydroxyethyl)2, 2′-azobisisobutyate was prepared from 2,2′-azobisobutyronitrile(AIBN) and glycol. It was used as an initiator for synthesis of the dihydroxy-terminal polystyrene in toluene. A kinetic study of styrene polymerization has been carried out. From the kinetic data measured in toluene at 60　℃, the polymerization rate Rp is direct ratio to concentration of monomer([M]) and concentration of initiator([I])0.43. The appearance activation energy of the polymerization is 75.3 kJ/mol and the efficiency of the initiator, which is determined by dead-end polymerization technique is 0.76. The chain transfer constants to solvent (CS) is 1.94×10-3. The chain transfer constants to initiator (CI) is 0. The value of Kp/Kt1/2 at 60, 80　℃ is 2.26×10-2 (L/mol·s)1/2 and 3.78×10-2 (L/mol·s)1/2 respectively.