摘要
以单丙烯酸酯液晶单体(RLC)为成核剂,通过共混反应法对等规聚丙烯(iPP)进行改性,制备含β晶型的聚丙烯产品(β-iPP)。首先介绍了β-iPP的制备工艺,然后通过偏光显微镜、广角X射线衍射对纯iPP、iPP/RLC共混物的球晶结构进行了分析;最后通过X射线衍射、差示扫描量热分析等测试方法研究共混物的结晶结构、结晶行为和热性能。结果表明,液晶成核剂RLC能够诱导iPP生成β晶型;制备β-iPP的最佳工艺条件是RLC含量为0.5%(质量分数,下同),结晶温度为110℃;β晶型相比于α晶型处于热力学亚稳态,在升温过程中,会发生β晶向α晶的转变,但较高的升温速率会抑制这一转变。
β-form containing polypropylene was prepared using a liquid crystal monoacrylate monomer(RLC) as a nucleating agent.Polarized light microscope was adopted to study the nucleation process,crystallization behavior,and spherulites morphology of the polypropylene.The crystal structure was also investigated by X-ray diffraction and differential scanning calorimeter(DSC).When the mass fraction of RLC was 0.5 wt% and the crystallization temperature was 110 'C.Compared with crform,β-form was thermodynamically metastable and could be affected by the temperature fluctuation.The metalstable β-form could transform into crcrystal form,while a higher heating rate would inhibit this transformation.
出处
《中国塑料》
CAS
CSCD
北大核心
2015年第3期26-32,共7页
China Plastics
关键词
等规聚丙烯
Β晶型
液晶成核剂
共混改性
isotactic polypropylene
β-polymorph
liquid crystal nucleating agent
blending modification
