氢氧化镁/LLDPE/聚硅氧烷侧链液晶聚合物复合材料的流变、结晶、力学性能研究  

Rheological,Crystallization and Mechanical Properties of Magnesium Hydroxide/Linear Low Density Polyethylene/Polysiloxane Side Chain Liquid Crystal Polymer Composites

作　　者：管啸晓 赵建青[1] 王世茹 何奕迅 刘述梅[1] GUAN Xiao-xiao;ZHAO Jian-qing;WANG Shi-ru;HE Yi-xun;LIU Shu-mei(School of Materials Science and Engineering,South China University of Technology,Guangzhou 510640,China)

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

出　　处：《塑料工业》2020年第8期131-135,38,共6页China Plastics Industry

摘　　要：采用熔融共混挤出制备氢氧化镁(MH)/线型低密度聚乙烯(LLDPE)/聚硅氧烷侧链液晶聚合物(PSCTLCP),探讨了PSCTLCP用量对MH/LLDPE复合材料流变性能、结晶性能、力学性能的影响。研究发现,添加PSCTLCP可以降低复合材料的储能模量、损耗模量、复数黏度,改善复合材料的加工性能。同时,随着PSCTLCP含量的逐渐增加,复合材料的熔融焓由7.57 J/g上升到12.33 J/g,结晶度由6.65%逐渐增加到11.24%,过冷度由4.1℃下降至2.7℃,表明PSCTLCP可提高复合材料的结晶度和结晶速度,降低复合材料的结晶温度。此外,研究发现PSCTLCP虽可以在MH/LLDPE复合材料中原位形成“微纤”,且随着PSCTLCP含量的增加,微纤逐渐增加。但微纤容易从复合材料中剥离,表明PSCTLCP与MH/LLDEP复合材料的相容性较差,导致材料的刚性并未增强,但随着PSCTLCP含量的增加,复合材料缺口冲击强度由92.6 J/m增强至119.5 J/m,表明PSCTLCP可明显增强复合材料的韧性。Magnesium hydroxide(MH)/linear low density polyethylene(LLDPE)/polysiloxane side chain liquid crystal polymer(PSCTLCP)composites were prepared by melt blending extrusion.The effect of PSCTLCP contents on the rheological,crystallization and mechanical properties of MH/LLDPE/PSCTLCP composites were investigated.It is found that the storage modulus(G′),loss modulus(G″),and complex viscosity(η)of MH/LLDPE composites are reduced and the processability of the composites is enhanced by the addition of PSCTLCP.At the same time,with the increase of PSCTLCP,the melting enthalpy(ΔH m)of MH/LLDPE/PSCTLCP composites increases from 7.57 J/g to 12.33 J/g,the crystallinity(X c)of the composites increases from 6.65%to 11.24%,and the supercooling(△T)of the composites decreases from 4.1℃to 2.7℃,which indicates that the crystallinity and the crystallization rate of the composites are improved and the crystallization temperature of the composites is reduced.In addition,it is found that PSCTLCP is easily oriented into microfibers in the composites.With the increase of PSCTLCP contents,the number of liquid crystal fibers are gradually increased.However,the liquid crystal fibers are easy to peel out from the composites,which means that the compatibilities of PSCTLCP and MH/LLDPE composites are poor,resulting in the rigidity of the materials is not enhanced.However,with the increase of PSCTLCP content,the impact strength of the composites increases from 92.6 J/m to 119.5 J/m,indicating that the toughness of the composites is significantly enhanced by the addition of PSCTLCP.

关 键 词：侧链液晶 复合材料 流变性能 力学性能 结晶性能 

分 类 号：TQ320.4[化学工程—合成树脂塑料工业]