基于剪切蠕变回复测试的iPP/ABS共混物相容性评价

Compatibility Evaluation of iPP/ABS Blends Based on Shear Creep Recovery Test

相容性的表征是高分子共混改性的重要研究内容。常用的流变学表征方法主要基于动态频率扫描测试,而低频区的测试通常需要耗费较长的实验时间。以等规聚丙烯(iPP)/丙烯腈-丁二烯-苯乙烯接枝共聚物(ABS)共混物为研究对象,利用旋转流变仪的剪切蠕变回复模式评价高分子共混物的相容性,借助扫描电镜测试以进一步验证剪切蠕变回复测试得到的结论。结果表明:对于不同相形态的iPP/ABS不相容共混物,蠕变可回复柔量(Jr)显示出不同的现象。具有双连续相的共混物Jr值最大,而具有海-岛相结构的共混物的Jr值介于双连续相共混物与纯组分的Jr值之间。分别选用聚丙烯接枝马来酸酐(PP-g-MAH)和苯乙烯-乙烯-丁烯-苯乙烯嵌段共聚物(SEBS)为相容剂,增容后的iPP/ABS共混物的Jr值明显小于纯组分。该测试耗时相对较短,可以替代常见的表征方法来快速评价高分子共混物的相容性。

The characterization of compatibility is the key research content of polymer blending modification.The commonly used rheological characterization methods are mainly based on dynamic frequency scanning tests,while the tests in the low frequency region usually take long experimental time.Isotactic polypropylene(iPP)/acrylonitrile-butadiene-styrene graft copolymer(ABS)blends were investigated.The shear creep recovery mode of rotary rheometer was utilized to evaluate the compatibility of polymer blends.The obtained conclusions were further verified by using scanning electron microscopy.The results show that for incompatible iPP/ABS blends with different phase morphology,creep recoverable compliance(J r)exhibits different phenomena.The blends with co-continuous morphology show the highest creep recoverable compliance,while the J r values of the blends with sea-island morphology are between those of the blends with co-continuous morphology and the pure components.When maleic anhydride grafted polypropylene(PP-g-MAH)and styrene-ethylene-butylene-styrene block copolymer(SEBS)were selected as compatibilizers,respectively,the J r values of the compatibilized iPP/ABS blends are significantly lower than those of the pure components.This test is relatively short in time and could replace the common characterization methods to quickly evaluate the compatibility of polymer blends.