论文部分内容阅读
在环己烷溶剂中,以自制的叔丁基二甲基硅氧基丙基锂为引发剂,丁二烯为单体,四氢呋喃为结构调节剂,采用活性负离子聚合法合成了线形端羟基聚丁二烯(L-HTPB).在此基础上,以甲基三氯硅烷为偶联剂合成了星形端羟基聚丁二烯(S-HTPB).采用GPC和1H-NMR对L-HTPB和S-HTPB结构进行了表征,结果表明,采用负离子聚合法合成的2种聚合物具有相同的微观结构,且线形端羟基聚丁二烯的平均官能度大于1.9,星形端羟基聚丁二烯的平均支化度和平均官能度大于2.8,与理论设计值基本相符.另外,实验中通过调节溶剂中环己烷和四氢呋喃的比例来控制聚合物主链的微观结构.实验结果证实,随复配溶剂中环己烷用量的增加,聚合物1,4-结构相对含量逐渐增大,特别是顺式1,4-结构相对含量增大的趋势比较明显;当聚合溶剂采用单一的环己烷时,聚合物主链1,4-结构相对含量大于90%,顺式1,4-结构相对含量高达70%以上,聚合物主链中1,2-结构相对含量约为5.70%;相反,当聚合溶剂采用单一的四氢呋喃时,聚合物主链1,2-结构相对含量大于90%,而顺式1,4-结构相对含量趋于0,样品的外观表现为塑料.
In the cyclohexane solvent, home-made t-butyldimethylsiloxypropyl lithium as initiator, butadiene monomer, tetrahydrofuran as a structural modifier, the use of living anionic polymerization of linear hydroxyl terminated poly Butadiene (L-HTPB) .At the same time, the star-terminated hydroxyl polybutadiene (S-HTPB) was synthesized by using methyltrichlorosilane as coupling agent.L-HTPB And S-HTPB structures were characterized. The results show that the two polymers synthesized by anionic polymerization have the same microstructure and the average functionality of linear hydroxyl-terminated polybutadiene is more than 1.9. The average degree of branching and average functionality of the olefins is greater than 2.8, which is consistent with the theoretical design value.In addition, the microstructure of the main chain of the polymer is controlled by adjusting the ratio of cyclohexane and tetrahydrofuran in the solvent. The experimental results show that, With the increase of the amount of cyclohexane in the solvent, the relative content of the 1,4-structure of the polymer gradually increases, especially the relative content of the cis-1,4-structure tends to increase. When a single cyclohexane is used as the polymerization solvent , The relative content of 1,4-structure of the polymer main chain is more than 90%, and the cis 1,4-structure phase The relative content of 1,2-structure in the main chain of the polymer is about 5.70%. On the other hand, when a single tetrahydrofuran is used as the polymerization solvent, the relative content of 1,2-structure in the main chain of the polymer is more than 90% The relative content of cis-1,4-structure tends to zero, and the appearance of the sample is plastic.