长链支化制备高熔体强度PP的研究

Research of High-Melt-Strength Polypropylene Preparared by Long Chain Branching

通过长链支化来改性PP ,从而得到高熔体强度的PP。实验以丙烯酸酯类单体为接枝单体 ,过氧化物为引发剂 ,对PP进行了熔融接枝 ,重点考察了二官能团单体的改性情况。实验结果表明 ,二三官能团单体的改性效果较为明显 ;熔体流动速率随单体加入量增加而降低 ,随过氧化物浓度增加而升高 ;拉伸粘度谱图显示有明显的应变硬化现象 ;改性后产物的熔体强度变化明显 ;纯化后的产物经红外、差示扫描量热分析表明接枝反应的发生 ;

High-melt-strength polypropylene is achieved with modified PP through long chain branching.The melt grafing of acrylate onto PP using peroxide as a radical initiator has been studied;and the bifunctional monomer is studied in detail. The result shows that bifunctional and trifunctional monomers are preferable for enhancing the melt strength of PP;the melt flow rate decreases with increasing monomer concentration and decreasing peroxide concentration;the modified PP seems to have significant effect on its MS;the elongational viscosity graph shows the strain harden phenomena.The FTIR and DSC of the purified sols shows the occurrence of the grafting reaction;there is no macrogel in the materials produced using Soxhlet extraction.