The effects of carbon black (CB) content on the mechanical properties, hydrophobicity, electrical conductivity, morphology, and thermodynamic properties of the poly(lactic acid) (PLA/CB) composites were studied. The results showed that adding an appropriate amount of CB improved both the mechanical properties and hydrophobicity of PLA, but an excessive addition of CB reduced the mechanical properties of PLA/CB composites. The conductivity test results showed that when CB content was exceeded than12 wt%, there was no significant changes. The results of analyzing the barrier performance showed that less CB content helped to extend the path of water molecules; thus, the water barrier performance was slightly improved. However, CB and PLA had no chemical bonding reaction, thus, the oxygen permeability was greatly increased with increase of the CB content. The XRD results showed that an appropriate amount of CB could improve the crystallinity of PLA. It was shown by scanning electron microscopy (SEM) inspection that when the filler content increased from 4 to 12 wt%, the cross-sections of the PLA/CB composites became wavy and coarser, indicating that the morphology of the PLA/CB composites was gradually changed and became more and more brittle. Thermogravimetric analysis showed that thermal stability of PLA could be improved when CB ≤ 8 wt%. Differential scanning calorimetry (DSC) analysis showed that the glass transition temperature of PLA/CB composites was slightly higher than that of the pure PLA, whereas the melting temperature was slightly lower than that of the pure PLA. This new composite material with optimized CB content showed excellent properties.

研究了炭黑 (CB) 含量对聚乳酸 (PLA/CB) 复合材料的机械性能、疏水性、导电性、形态和热力学性能的影响。结果表明，加入适量的CB可以提高PLA的力学性能和疏水性，但过量加入CB会降低PLA/CB复合材料的力学性能。电导率测试结果表明，当CB含量超过12wt%时，无明显变化。阻隔性能分析结果表明，较少的CB含量有助于延长水分子的路径；因此，防水性能略有提高。然而，CB和PLA没有化学键合反应，因此，随着CB含量的增加，透氧性大大增加。XRD结果表明适量的CB可以提高PLA的结晶度。扫描电子显微镜（SEM）观察表明，当填料含量从 4% 增加到 12 wt% 时，PLA/CB 复合材料的横截面变得波状和粗糙，表明 PLA/CB 复合材料的形貌是渐渐地变了，变得越来越脆。热重分析表明，当 CB ≤ 8 wt% 时，可以提高 PLA 的热稳定性。差示扫描量热法 (DSC) 分析表明，PLA/CB 复合材料的玻璃化转变温度略高于纯 PLA，而熔化温度略低于纯 PLA。