超薄微注塑等规聚丙烯制品形态结构及注射速度的影响分析  

Influence of Injection Speed on Morphology and Structure of the Ultra-Thin Micro Injection Molded Isotactic Polypropylene Parts

作　　者：王利霞[1,2] 李爽[1] 王心超[1] 卞宁[1] 蒋林[1] 李倩[1,2] 申长雨[1] 

机构地区：[1]郑州大学橡塑模具国家工程研究中心,河南郑州450002 [2]郑州大学微纳成型技术国家级国际联合研究中心,河南郑州450001

出　　处：《高分子材料科学与工程》2015年第1期120-125,132,共7页Polymer Materials Science & Engineering

基　　金：国家自然科学基金资助项目(11372287);国家基础研究项目(2012CB626809)

摘　　要：针对100μm和200μm厚的2种超薄微制品,采用单因素实验,对等规聚丙烯微注塑制品的形态结构进行研究,并分析注射速度对超薄微注塑制品形态结构的影响。研究结果表明,超薄微注塑制品中呈现出2种典型的形态结构,200μm微制品厚度方向呈现出纯剪切层的无芯结构,剪切层内为明显的Shish-Kebab结构;100μm厚微制品内部形态为含大比例柱晶结构的皮芯结构;广角X射线衍射结果显示无芯结构内形态沿流动方向呈现高度取向,且β晶含量微弱。含柱晶层皮芯结构的取向也较明显,且结构中有明显β晶存在。注射速度对超薄微注塑制品的形态结构、结晶度和取向度都有重要的影响,存在临界注射速度,当注射速度小于该临界速度时,制品内部结晶度、取向度随着注射速度的提高而提高。The morphology and structure of the ultra-thin micro injection molded isotactic polypropylene parts were investigated by single-factor experiments methods for two kinds of the micro parts with the thickness of 100μm and 200μm,and influence of the injection speed on the morphology and structure was analyzed.The results indicate that two kinds of typical morphology were observed in the parts,the parts with the thickness of 200μm have a core-free shear layer structure with shish-kebab structure in the whole thickness direction,while the parts with the thickness of 100μm have a skin-core layer structure with large fraction of columnar crystal next to shear layer in the thickness direction.WAXD results indicate the crystalline morphology is high oriented along flow direction in core-free structure,and littleβ-phase crystals are observed;the orientation is also observed in the columnar crystal layer skin-core structure,and theβ-phase crystals are obvious.Injection speed has significant influence on the morphology and structure,crystallinity and orientation of the ultrathin micro injection molded isotactic polypropylene parts.There exists a critical injection speed,and the crystallinity and orientation both increase with the injection speed increasing when the injection speed is lower than the critical speed.

关 键 词：微注塑成型 形态结构 注射速度 串晶结构 柱晶结构 

分 类 号：TQ325.14[化学工程—合成树脂塑料工业]