PP/EVA复合发泡材料的制备与性能研究

Preparation and Performance of PP/EVA Foamed Composite Materials

以高熔体强度聚丙烯(PP)和乙烯-醋酸乙烯共聚物(EVA)为主要原料,通过化学-模压发泡法制备聚丙烯/乙烯-醋酸乙烯酯(PP/EVA)发泡复合材料并采用差示扫描量热仪(DSC)、扫描电子显微镜(SEM)、旋转流变仪等设备对复合材料测试分析,研究了不同含量EVA对PP发泡性能及力学性能的影响。结果表明,EVA的加入对PP的结晶度影响不大;当EVA添加量为5%时,复合发泡材料的弯曲强度明显提高,从10.8 MPa提高到了15.5 MPa,但对拉伸强度影响不大;同时,复合材料泡孔孔径从68.36μm减小到33.58μm,孔径分布更均匀;在EVA添加量为5%时,泡孔平均直径达到最小值,泡孔密度达到最大值,泡孔孔径分布最集中。

PP/EVA foamed composite materials were prepared by a chemical‑mold foaming method using high‑melt strength polypropylene(PP)and ethylene‑vinyl acetate(EVA)as raw materials,and their structure and performance were characterized by using differential scanning calorimeter,scanning electron microscope,rotational rheometer,and other equipment.The effect of EVA content on their foaming performance and mechanical properties were also investigated.The results indicated that there was no significant change in the crystallinity of PP with the addition of EVA.The formed composite materials at an EVA content of 5 wt%achieved a significant improvement in flexural strength from 10.8 to 15.5 MPa compared to pure PP forming material.However,there is little effect on tensile strength.The formed composite materials also presented a decrease in cell pore size from 68.36 to 33.58μm in the presence of EVA,and their pore size distribution became more uniform.In addition,the formed composite materials containing 5 wt%EVA achieved a maximum cell density and a minimum average cell diameter with the most concentrated size distribution.