聚乙烯醇纤维增强聚乳酸复合材料的制备及性能研究

Preparation and properties of polyvinyl alcohol fiber reinforced poly(lactic acid)composites

以聚乳酸(PLA)和高强高模聚乙烯醇(PVA)纤维为原料,通过熔融共混热压成型工艺制备了不同PVA纤维含量的PLA/PVA复合材料,研究了复合材料的相形态、玻璃化转变、结晶和熔融行为以及力学性能。结果表明:低含量的PVA纤维能均匀地分散在PLA基体中,当纤维质量分数达到20%时,纤维发生团聚。差示扫描量热仪测试结果表明PVA纤维在PLA结晶过程中起到了成核作用。随PVA纤维含量增加,PLA的结晶度增加。此外,动态力学行为表明PVA纤维含量的增加有助于提高复合材料储能模量和刚性。复合材料的拉伸和弯曲模量随PVA纤维含量的增加而增加,当PVA纤维质量分数为20%时,拉伸和弯曲模量达到最大,与纯PLA相比,复合材料的拉伸和弯曲模量分别提高了43.5%和38.6%。但是,PVA纤维的加入并没有使复合材料的拉伸和弯曲强度得到较大改善。

Poly(lactic acid)(PLA)and high strength,high modulus polyvinyl alcohol(PVA)fibers were used as raw materials to prepare PLA/PVA composites with different PVA fiber contents by melting blending hot pressing process.The phase morphology,glass transition,crystallization,melting behavior and mechanical properties of the composites were studied.The results showed that the low content of PVA fibers could be uniformly dispersed in the PLA matrix,and when the fiber mass fraction reached 20%,the fibers agglomerated.Differential scanning calorimeter test results demonstrated that PVA fibers played a nucleating role in the crystallization process of PLA.The crystallinity of PLA increased with the increase of PVA fiber content.Furthermore,the dynamic mechanical behavior indicated that the increase of PVA fiber content contributed to the improvement of the storage modulus and stiffness of the composites.The tensile and flexural modulus of the composites increased with the increase of PVA fiber content.When the mass fraction of PVA fibers was 20%,the tensile and flexural modulus reached the maximum.Compared with pure PLA,the tensile and flexural modulus of the composite increased by 43.5%and 38.6%,respectively.However,the addition of PVA fibers did not greatly improve the tensile and flexural strengths of the composites.