对氯/对甲基二苄叉山梨醇组合物对聚丙烯的成核作用

以摩尔比为1∶1∶1的对甲基苯甲醛、对氯苯甲醛和山梨醇为反应物,制备了含非对称型对氯/对甲基二苄叉山梨醇(DMCBS)的组合物;采用HPLC-MS技术表征了DMCBS组合物的组成;考察了DMCBS组合物、对称型1,3∶2,4-二(对甲基苄叉)山梨醇(DMBS)和对称型1,3∶2,4-二(对氯苄叉)山梨醇(DCBS)3种成核剂对聚丙烯(PP)的结晶温度、雾度和弯曲模量的影响。表征和实验结果表明,DMCBS组合物中含有24%(w)的DMBS、19%(w)的DCBS和57%(w)的DMCBS,在PP中DMCBS的各组分之间存在盐析效应;随PP中DMCBS组合物、DMBS和DCBS含量的增加,PP的结晶温度提高、雾度降低、弯曲模量增大。与纯PP相比,含0.40%(w)DMCBS组合物的PP的结晶温度提高了16.2℃,雾度从76.8%降低到17.9%,弯曲模量提高了43.5%。

Nucleation of Di-(p-Methyl/Chloro Benzylidene) Sorbitol Composition in Polypropylene

Di-(p-methyl/chloro benzylidene) sorbitol(DMCBS) composition was synthesized from p-methyl benzaldehyde,p-chloro benzaldehyde and sorbitol with mole ratio of 1 ∶ 1 ∶ 1 and was characterized by means of HPLC-MS.The effects of DMCBS composition,di-(p-methyl benzylidene) sorbitol(DMBS) and di-(p-chloro benzylidene) sorbitol(DCBS) as nucleating agents on crystallization temperature(tc),haze and flexural modulus of polypropylene(PP) were investigated.The results indicated that DMCBS composition comprised 24%(w) DMBS,19%(w) DCBS and 57%(w) DMCBS.There was salting out effect between the components of DMCBS composition in PP.The flexural modulus and tc of PP increased gradually and its haze decreased with the increase of the DMCBS composition dosage.The flexural modulus and tc of PP with 0.40%(w) DMCBS composition increased by 43.5% and 16.2 ℃ respectively,and the haze decreased from 76.8% to 17.9%.