摘要
采用热台偏光显微镜(POM)和差示扫描量热仪(DSC)研究了等规聚丙烯(iPP)和茂金属线性低密度聚乙烯(m-LLDPE,己烯共聚单体含量为24%)共混体系的等温结晶形态和结晶动力学。将组成分别为70/30,50/50,30/70(w/w)的iPP/m-LLDPE共混物从熔体状态冷却至结晶温度,使iPP可以结晶,而m-LLDPE处于熔体状态。POM的研究结果表明,当共混物中iPP的含量≥50%时,生长的iPP球晶可以包裹m-LLDPE的分散相,iPP球晶的生长速率与m-LLDPE的含量无关;当m-LLDPE的含量达到70%时,iPP作为分散相在m-LLDPE的基体相中结晶,iPP球晶的生长受到自身相区的限制,尺寸明显细化。DSC的研究发现共混物中iPP的半结晶时间与纯iPP相近,表明iPP与己烯共聚单体含量为24%的m-LLDPE熔体在实验温度下是不相容的。
The isothermal crystallization kinetics and morphology for the binary blends consisting of an isotactic polypro- pylene （iPP） and a metallocene - prepared linear low - density polyethylene （ m - LLDPE, containing 24% hexene comonomer） with three different weight ratios of 70/30, 50/50 and 30/70 were examined by using a differential scanning calorimeter （DSC） and a hot stage polarized optical microscope （POM） , respectively. The blends were cooled from the melt to room temperatures where PP could crystallize and grow around m - LLDPE. The results from POM showed that the growth rate of PP spherulites was independent of m - LLDPE content and m - LLDPE remained as droplets within the iPP spherulites in the iPP/m - LLDPE 70/30 and 50/50 blends. DSC studies showed that the half - crystallization time for iPP in the blend was very similar to that of pure iPP, suggesting that there was no miscibility between the two components in the molten state.
出处
《中国材料进展》
CAS
CSCD
2009年第1期60-64,共5页
Materials China
基金
国家基础研究专项经费资助(2005CB623800)
