The difference between apparent grafting ratio and true grafting ratio in bulk graft copolymerization of styrene onto rubber and the change of rubber particle size during the overall polymerization processes were stud...The difference between apparent grafting ratio and true grafting ratio in bulk graft copolymerization of styrene onto rubber and the change of rubber particle size during the overall polymerization processes were studied. The results show that, the apparent grafting ratio increased mutationally at the phase inversion and trended to level off after the phase inversion, but the true grating ratio increased gradually with the increase of conversion. At the same time, the particle size of rubber phase in the original polymerizing mixtures almost kept constant after the phase inversion. On the contrary, the size increased with the increase of conversion when the samples were dealt with multi-solution-centrifugation.展开更多
采用种子乳液聚合技术在聚丁二烯(PB)乳胶粒子上接枝共聚苯乙烯(St)和丙烯腈(AN)合成了一系列PB质量分数为40%的PB g SAN弹性体·研究了共聚单体中叔 十二烷基硫醇(TDDM)质量分数对SAN共聚物接枝行为、弹性体粒子结构及其动态力学...采用种子乳液聚合技术在聚丁二烯(PB)乳胶粒子上接枝共聚苯乙烯(St)和丙烯腈(AN)合成了一系列PB质量分数为40%的PB g SAN弹性体·研究了共聚单体中叔 十二烷基硫醇(TDDM)质量分数对SAN共聚物接枝行为、弹性体粒子结构及其动态力学性能的影响·结果发现,随着单体中TDDM质量分数的增加,SAN在PB上的接枝率和接枝效率降低,弹性体粒子中SAN包容结构的尺寸增大,在低温区的动态剪切模量下降·将其与SAN树脂共混后发现在共聚单体中引入TDDM后提高了弹性体粒子的增韧效率·展开更多
文摘The difference between apparent grafting ratio and true grafting ratio in bulk graft copolymerization of styrene onto rubber and the change of rubber particle size during the overall polymerization processes were studied. The results show that, the apparent grafting ratio increased mutationally at the phase inversion and trended to level off after the phase inversion, but the true grating ratio increased gradually with the increase of conversion. At the same time, the particle size of rubber phase in the original polymerizing mixtures almost kept constant after the phase inversion. On the contrary, the size increased with the increase of conversion when the samples were dealt with multi-solution-centrifugation.
文摘采用种子乳液聚合技术在聚丁二烯(PB)乳胶粒子上接枝共聚苯乙烯(St)和丙烯腈(AN)合成了一系列PB质量分数为40%的PB g SAN弹性体·研究了共聚单体中叔 十二烷基硫醇(TDDM)质量分数对SAN共聚物接枝行为、弹性体粒子结构及其动态力学性能的影响·结果发现,随着单体中TDDM质量分数的增加,SAN在PB上的接枝率和接枝效率降低,弹性体粒子中SAN包容结构的尺寸增大,在低温区的动态剪切模量下降·将其与SAN树脂共混后发现在共聚单体中引入TDDM后提高了弹性体粒子的增韧效率·
