PP/EVOH共混物结构与性能研究

Structure and Properties of PP/EVOH Blends

采用丙烯酸接枝聚丙烯(PP-g-AA)、衣康酸接枝聚丙烯(PP-g-ITA)、马来酸酐接枝聚丙烯(PP-g-MAH)3种相容剂增容聚丙烯(PP)/乙烯-乙烯醇共聚物(EVOH)共混体系,研究了共混体系的相容性、热性能、力学性能和阻透性能。红外光谱分析表明,相容性的改善源于相容剂与EVOH之间形成的酯键和氢键。扫描电镜显示,PP-g-AA、PP-g-ITA、PP-g-MAH的增容作用依次增强,共混体系中相容剂增容作用越强,分散相尺寸越小,界面结合越牢固。差示扫描量热分析发现,PP/EVOH增容共混体系中EVOH组分的结晶温度低于不含相容剂的共混体系EVOH组分的结晶温度,PP组分的结晶温度变化则相反。增容共混体系与不含相容剂的共混体系相比,拉伸强度提高了10MPa,吸油率降幅达0.8%。

The compatibility, thermal behavior, mechanical properties and barrier performance of the blends of PP/poly （ethylene-co-vinyl alcohol） （EVOH） containing three kinds of compatibilizers（PP-g- AA, PP-g-ITA and PP-g-MAH） were investigated. Infrared spectra analysis indicated that the improvement of compatibility resulted from the formation of ester bonds and hydrogen bonds between com- patibilizers and EVOH. Scanning Electron Microscopy observations showed that the presence of compatibilizers in the PP/EVOH blends reduced the size of the dispersed phase. Differential scanning calorimetry analysis showed that the compatibilizers lowered the crystallization temperature of dispersed EVOH phase, but increased that of PP phase. Compared with the uncompatibilized blends, the tensile strength of the compatibilized blends was increased by 10 MPa, and the oil absorption rate was decreased by0.8 %.