二氯二茂钛催化丙烯腈溶液聚合的动力学研究

二氯二茂钛催化丙烯腈溶液聚合的动力学研究 KINETIC STUDIES ON SOLUTION POLYMERIZATION OF ACRYLONITRILE IN THE PRESENCE OF TITANOCENE DICHLORIDE 刘道玉 first-author 叶大铿 李贵华 刘德海 秦金贵 在光照射下,以苯、四氯化碳、二氧六环和二甲亚砜为溶剂,研究了二氯二茂钛催化丙烯腈和甲基丙烯酸甲酯的溶液聚合动力学。结果表明,当温度升高时,聚合速度增大,而过量的二甲亚砜会使二氯二茂钛失活。测定和计算了丙烯腈在二甲亚砜中溶液聚合速度与二氯二茂钛用量和丙烯腈浓度的关系,其关系式是: R p =k[C p2 TiCl 2 ] 1/2 [M] 3/2 这是自由基聚合所应遵循的关系式。测定了相应于不同二氯二茂钛和单体浓度的聚丙烯腈分子量,以及在50℃下,丙烯腈于二甲亚砜中聚合的链转移常数是:C 2 =1.07×10 -4 . The kinetics of solution polymerization of acrylonitrile（AN） and methyl methacrylate in benzene, carbon tetrachloride, dioxane and dimethyl solfoxide （DMSO） in the presence of titanocene dichloride（Cp 2 TiCl 2 ） under the irradia tion of visible light were studied. The results show that the polymerization rates in the four solvents increase with increasing temperature, and the rate decreases after about twenty minutes in DMSO, activity of the catalyst may be partly losed since reaction between Cp 2 TiCl 2 and exceed DMSO exists. Analysis of the results show that the polymerization rate of AN in DMSO is proportional to [Cp 2 TiCl 2 ]and[M] and the rate equation is as. R p =k[Cp 2 TiCl 2 ] 1/2 [M] 3/2 The equation indicates a free-radical mechanism of the polymerization. the molecular weights of polyacrylonitrile obtained at various concentrations of Cp 2 TiCl 2 and monomer were measured. The chain trasfor constant, C 8 , of AN polymerization in DMSO In the presence ef Cp 2 TiCl 2 at 50℃ and under the irradiation of light was obtained as 1.07×10 -4 . 1983-04-01 2021-04-01 4