PBT/EVA共混体系相容性、相态及结晶形态的考察

Compatibility, Morphology and Crystallization of PBT/EVA Blend

讨论了PBT/EVA共混体系的相容性、相态及结晶形态。实验发现,PBT/EVA共混具有一定程度的相容性。对于不同模式的共混方法,共混相态差别较大。以双螺杆挤出机挤出共混相态分散均匀,相域较小,而单螺杆挤出机挤出共混分散较差,相域大且有包藏结构。PBT/ENA共混呈海岛结构,且相域界面有一定程度的层过渡。对共混体系的结晶度及结晶形态考察发现,结晶温度对结晶形态影响较大,而温度和组份比的影响对结晶度较小(≤10％),有趣的是在高于EVA熔点温度下EVA组份有反常结晶现象。本工作对研究PBT的复合改性有一定的指导意义。

Compatibility, morphology and crystallization of PBT/EVA blend are discussed in this paper. It is found that PBT and EVA are compatible with each other to a certain degree and that the morphology of PBT/EVA blend is different with different mixing mode. The morphologies of PBT/EVA blend with single and twin screw extruder are revealed respectively. The dispersion of EVA in PBT with the latter is more uniform than with the former. The morphology of PBT/EVA blend appears 'sea-island' structure, and there are some layers between blend interface. Crystallinity and crystalling morphology of PBT/EVA are also discussed. The influence of crystallizing temperature on crystallizing morphology is greater, but that on crystallizing is less (≤10%) . An intersting phenomenum noticed was that above the melting point of EVA, unusual crystallization occurs.