The chance of chain transfer reaction and the viscosity of solution increases with the increase of dosage of initiator, so efficiency of initiator and [ n] of copolymer decrease. 但活性中心浓度增加的同时相应增加了链转移的机会,也使得体系粘度迅速增加,因此造成催化效率及共聚物[η]下降。
The influential factors upon the title film appearance and properties are analyzed, including hydrophilic substance, crosslinking agent, chain extender, initiator, neutralized agent, and organic solvent, etc. 分析了亲水性物质、交联剂、扩链剂、引发剂、中和剂、有机溶剂等对水性聚氨酯涂膜外观及性能的影响。
In this paper, chain transfer constant of graft copolymerization of SBS and MMA was determined. The influence on chain transfer constant of initiator concentration, reaction temperatures and solvents was discussed. 测定了MMA与SBS接枝共聚合的链转移常数,讨论了引发剂浓度、温度及溶剂对链转移常数的影响。
There was chain degradation of PP with low content of LDPE in the system, whereas the crosslinkage plays a leading role when the content of LDPE is over 28%, and also the degree of crosslink-age increases with the increase of the content of the initiator. 当LDPE质量分数低时,体系以PP的降解为主,当LDPE质量分数超过28%时,交联占据主导地位;且随着引发剂DCP质量分数增加,体系交联程度增加。
It was also found that long chain branches can be formed at rather low initiator feed in the presence of styrene. 在苯乙烯存在下只需较低的引发剂用量,经历一定的反应时间就有长支链形成。
In our study, we control the length of the chain by changing the initiator amount in order to change the grafting ratio. With the increase of initiator amount, the grafting ratio decreases. 在实验过程中,我们通过改变引发剂量的加入来调节接枝链的长短,进而调节接枝率,引发剂加入量越多,接枝率越低。
The formation of long chain branches was affected by factors such as reaction temperature, feed ratio of initiator, styrene feed and reaction time. 反应温度、引发剂用量、单体用量以及反应时间等因素对长支链的形成也有影响。