【摘要】 本文以叔丁氧基钾-正丁基锂作引发剂,甲苯作溶剂及链转移剂,研究了丁二烯阴离子链转移反应若干影响因素。含不同反离子引发剂的聚合体系中,向甲苯的链转移常数C_?分别为:C_?（Li）=0.11×10^-3,C_?（Na）=0.40×10^-3,C_s（K）=1.43×10^3-（K/Li=1.1）,C_?（K）=1.26×10^-3（K/Li=0.5）。温度每升高10℃,增长速率常数增加1.7倍左右,而转移速率常数则增大2.1倍,表观转移活化能为62.8kJ/mol。随着K/Li的增大,链转移常数相应增大,当K/Li从0增加到0.5时,C_?增大约10倍,当K/Li从0.5增加到1.1时,C_s的变化很小。体系中可能存在向单体的链转移反应。更多还原

【Abstract】 The chain transfer of butadiene polymerization was studied with n-butyl lithium and potassium butoxide as catalyst, toluene as solvent and chain transfer agent. The chain transfer constants to toluene with different counterions were found to be:C_s（Li）=0.11x10^-3, C_s（Na）=0.40x10^-3, C_s（K）=1.43x10^-3, （K/Li=1.1）, C_s（K）)=1.26x10^-3K/Li=0.5) respectively. The propagation rate constant increased 1.7 times for every 10℃ increase in temperature, and the chain transfer rate constant increased 2.1 times. The apparent activation energy of chain transfer was 62.8 kJ/mol. When increeasing K/Li from 0 to 0.5, C_s increased about 10 times, but when K/Li increased from 0.5 to 1.1, C_s changed scantly. Probably there existed certain chain transfer to monomer in this system.更多还原