ABSTRACT

Novel intralayer hybrid composites (IHC) based on a commercial polylactic acid (PLA) matrix reinforced with a hybrid plain-woven fabric, composed of PLA filaments and sisal fibers, were obtained by film stacking followed by compression molding. Two different stacking configurations were explored. In one configuration, weft and warp directions of all fabric layers were equally oriented whereas in the other configuration, weft and warp directions of fabric layers were alternately oriented. The effect of the stacking sequence on the materials morphology and thermal and tensile behavior was investigated. All obtained composites presented higher thermal stability than the matrix due to the presence of the natural fibers and PLA filaments and also, the existence of lignocellulosic compounds in the woven fabric led to a char yield residue, with the expected improvement of flame retardant properties. Although both IHCs exhibited highly anisotropic tensile behavior, the composite having an alternated fabric layers configuration, presented a good balance of stiffness and strength for the two main orthogonal loading directions.

摘要

新型层内混合复合材料 (IHC) 基于商用聚乳酸 (PLA) 基体，由混合平纹织物增强，由 PLA 长丝和剑麻纤维组成，通过薄膜堆叠和压缩成型获得。探索了两种不同的堆叠配置。在一种配置中，所有织物层的纬向和经向定向相同，而在另一种配置中，织物层的纬向和经向交替定向。研究了堆叠顺序对材料形态以及热和拉伸行为的影响。由于天然纤维和 PLA 长丝的存在，所有获得的复合材料都表现出比基体更高的热稳定性，而且机织织物中木质纤维素化合物的存在导致焦炭残留，随着阻燃性能的预期改善。尽管两种 IHC 都表现出高度各向异性的拉伸行为，但具有交替织物层配置的复合材料在两个主要正交加载方向上表现出良好的刚度和强度平衡。