不同接枝率的增容剂对PA66/PP共混物结构与性能的影响

Influences of Compatibilizers with Different Graft Ratio on Structure and Mechanical Properties of PA66/PP Blends

用熔融接枝的方法以苯乙烯(St)作共单体将马来酸酐(MAH)接枝于乙丙共聚物VERSIFY(V)上,制得不同MAH相对接枝率的接枝物V-g-(MAH-co-St),用双螺杆挤出机制备了V-g-(MAH-co-St)增容的尼龙(PA)66/聚丙烯(PP)共混物。利用扫描电子显微镜、熔体流动速率(MFR)和力学性能等测试方法,研究了不同MAH相对接枝率的增容剂V-g-(MAH-co-St)对PA66/PP共混物形态结构和力学性能的影响。结果表明,提高St的含量可以得到高MAH相对接枝率的V-g-(MAH-co-St),当MAH/St质量比从2/1变为1/1时,接枝率显著提高,继续提高St含量,接枝率提高幅度减小。V-g-(MAH-co-St)可使共混物中PP分散相的尺寸减小、分散均匀。当增容剂质量分数从0%增加到10%时,共混物的力学性能在总体上得到提高,MFR迅速降低;增容剂中MAH相对接枝率越高,共混物的弯曲强度越高,MFR越低,而缺口冲击强度相差不大。当增容剂质量分数从10%增加到25%时,共混物的缺口冲击强度大幅提高,且MAH相对接枝率越高,其提高的幅度越大,但拉伸强度和弯曲强度均明显下降,MFR下降幅度变小。

Through melt-grafting maleic anhydride （MAH） onto ethylene-propylene copolymer [VERSIFY（V）] with taking styrene（St） as the co-monomer, the grafted materials [V-g-（MAH-co-St）] with different MAH relative grafting ratio were made. Then the PA66/PP blends which were compatibilized by the grafted materials were prepared via twin-screw extruder. Using SEM, MFR and mechanical properties testing methods, the influences of the grafted materials with different MAH relative grafting ratio on the structure and mechanical properties of the PA66/PP blends were studied. The results show that improving St content can obtain a high MAH relative grafting ratio of the graft materials, when the mass ratio of MAH / St changes from 2 / 1 to 1 / 1, the grafting ratio increases significantly but increase slightly when the St content is continued to improve. The graft materials V-g-（MAH-co-St） can reduce the size of PP dispersed phase in the blend and distribute it evenly. When the mass fraction of the compatibilizer increases from 0% to 10%, the mechanical properties of the blends improve generally, while MFR decreases rapidly. The MAH relative grafting ratio is higher, the flexural strength of the blend is higher, MFR is lower but the difference of the notched impact strength is little. When the mass fraction of the compatibilizer increases from 10% to 25%, the notched impact strength of the blend improves greatly, and the MAH relative grafting rate is higher, the increase is higher, while the tensile strength and bending strength both decrease obviously, MFR decreases slightly.