双单体接枝物增容PP／EVOH共混物形态结构及性能

Effect of Graft Copolymer of Polypropylene on the Properties of PP/EVOH Blend

采用反应型双螺杆挤出机制备了双单体接枝物聚丙烯(PP)接枝马来酸酐(MAH)和三烯丙基异氰脲酸酯(TAIC)[PP-g-(MAH-co-TAIC)],并以此增容PP/乙烯-乙烯醇共聚物(EVOH)共混物。研究了共混增容体系的相容性、流变性能、结晶性能、力学性能和阻透性能。红外光谱分析表明,接枝物加入后,在EVOH的羟基和接枝物的酸酐基团之间发生了反应,体系的相容性因此得以改观;TAIC的加入使PP的接枝率提高了13%;扫描电子显微镜观察证实,接枝物的加入促进了EVOH和PP之间的界面结合,减小了分散相的尺寸;流变性能测试表明,TAIC的加入抑制了PP的降解;差示扫描量热仪分析表明,接枝物的加入使得PP和EVOH的结晶温度得到了提高。双单体接枝物的共混体系与单一单体接枝物的共混体系相比,对力学性能影响不大,但阻透性能有所提高,当共单体添加量为0.4份(质量份,下同)时,体系的阻透性能提高了28%。

Polypropylene was grafted with maleic anhydride （MA） and triallyl isocyanurate （TALC） in a twin-screw extruder and used as a compatibilizer for PP/EVOH blends. The compatibility, theological behavior, crystallization behavior, mechanical properties, and barrier performance of the blends were studied. The grafting degree was increased by 13% through the grafting of TAIC. Infrared spectra analysis indicated that the compatibility was improved by the esterification between compatilizers and EVOH. Scanning electron microscopy observation revealed the smaller size of the dispersed phase. Rheological experiments indicated that the TAIC grafting suppressed the degradation of PP. Differential scanning calorimetry analysis showed that the crystallization temperatures of PP and EVOH in the compatibilized blend were higher than those in the uneompatibilized blends. The incorporation of TAIC had little effect on the mechanical properties, however, showed major effect on the barrier property. When the loading of TAIC was 0. 4 phr, the barrier performance was increased by 28 %.