乙烯-醋酸乙烯酯/聚甲醛共混改性的研究

Study on the Blending Modification of Ethylene Vinyl Acetate and Polyoxymethylene

本文通过熔融共混法制备了醋酸乙烯(VA)含量不同的乙烯-醋酸乙烯酯(EVA)/聚甲醛(POM)复合材料.研究表明,VA含量对POM/EVA共混体系的结构与性能有显著地影响.扫描电子显微镜(SEM)的观察结果表明,POM/EVA体系为相分离形态,其形态分布受到VA含量的影响.力学性能研究表明,POM/EVA50共混体系与纯的POM相比断裂伸长率增加了360%,但与EVA28,EVA70熔融共混时,却没有明显的改变.同时红外光谱分析与X射线衍射分析表明,通过简单的熔融共混在不改变聚合物基体结晶性能的情况下,仍能够有效地改善POM基体的力学性能,达到增韧的效果.

Ethylene vinyl acetate copolymers （EVA） with various vinyl acetate （VA） contents have been used to modify polyoxymethylene （POM） by simply melt blending. The VA content effects in EVA on the structure and properties of the prepared POM/EVA blends have been investigated systematically. The scanning electron microsco- py （SEM） results show the phase separated morphologies of the POM/EVA blends which dependent on the VA con- tents in EVA. Study on mechanical properties of POM/EVAS0 blends showed that compared with the pure POM e- longation increased by 360%, in contrast no drastic improvements are observed when using EVA 28 and EVA 70 as the modifier for POM. At the same time, infrared spectrum and X ray diffraction analysis shows that a simple melt blending does not change in the crystallization performance of matrix polymer, but still can improve the mechanical properties of POM matrix.