β成核剂改性PPR/iPP共混物的力学性能与结晶结构的关系  

Relationship Between Mechanical Properties and Crystalline Structure of PPR/iPP Blends Modified with β-Nucleator

作　　者：朱亚明[1] 刘述梅[1] 蒋文真 周延辉[1] 赵建青[1] 

机构地区：[1]华南理工大学材料科学与工程学院,广东广州510640 [2]广州市合诚化学有限公司,广东广州510620

出　　处：《华南理工大学学报（自然科学版）》2011年第6期77-83,共7页Journal of South China University of Technology(Natural Science Edition)

基　　金：广东省教育部产学研结合项目-基地建设专项(2009B090200025);广东省教育部产学研结合项目(2010B090400150)

摘　　要：利用差示扫描量热法和X射线衍射法研究了稀土配合物(β成核剂)改性无规共聚聚丙烯(PPR)/等规聚丙烯(iPP)共混物的力学性能和结晶结构的关系.结果表明:添加0.05%的β成核剂能够大幅度地提高PPR、PPR/iPP(质量比分别为70/30、50/50、30/70)共混物、iPP的冲击韧性,缺口冲击强度分别从42.7、33.7、14.5、8.3、5.1 kJ/m2上升至87.8、63.4、29.3、13.9、8.2 kJ/m2,而拉伸强度下降幅度均在10%以内;加入0.05%成核剂后,PPR/iPP(质量比70/30)共混物的熔融峰温从161.9℃降至149.8℃,β晶相对含量从45.3%增至53.1%,有明显的β晶成核促进作用;冲击断面的扫描电镜照片显示,该体系呈现明显的韧性断裂特征;成核剂用量增至0.20%时,共混物熔融峰温为159.8℃,β晶相对含量为45.1%,成核剂对共混物β晶的成核作用减弱,增韧作用降低.In this paper,the relationship between the mechanical properties and the crystalline structure of propy-lene random copolymer（PPR）/isotactic polypropylene（iPP） blends modified by a rare earth complex（β-nucleator） was investigated by means of DSC and XRD.When the dosage of β-nucleator is kept at 0.05%,it is found that（1） the impact strengths of PPR,PPR/iPP（70/30,50/50 and 30/70 in mass ratio,respectively） blends and iPP increase from 42.7,33.7,14.5,8.3 and 5.1kJ/m2 to 87.8,63.4,29.3,13.9 and 8.2kJ/m2,respectively,while the tensile strengths all decrease by less than 10%;（2） the melting temperature of PPR/iPP（70/30 in mass ratio） blend decreases from 161.9℃ to 149.8℃ and the relative content of β-form crystal increases from 45.3% to 53.1%,which reveals a remarkable nucleating promotion to β-form crystal;and（3） there exist typical ductile fractures in the impact-fractured sections of the blend,which is verified by the SEM photographs.More-over,when the dosage of β-nucleator increases to 0.20%,the melting temperature of the blend and the relative content of β-form crystal respectively reach 159.8℃ and 45.1%,and the nucleation to β-form crystal of the blend weakens,thus resulting in a decrease in the impact toughness.

关 键 词：聚丙烯 共混 增韧 成核 晶型 

分 类 号：TB324[一般工业技术—材料科学与工程]