关键词: 剑麻, 聚乳酸, 转矩流变仪, 流变性能, 长径比

Abstract:

Rheological properties of polylactic acid/sisal fiber composites with different sisal fiber mass fraction were evaluated by the method of torque rheometer rheological properties testing.The lengths and widths of sisal fibers in the composites and the molecular weights of polylactic acid, including the processed materials and unprocessed PLA were measured.The effect of sisal fiber mass fraction and rotor speed on the length of sisal fiber in the composites were analysed.The degradation status of polylactic acid was also analyzed.The results showed that the non-Newtonian index of composites presented a peak at the sisal fiber mass fraction about 10%, then decreased with further increasing mass fraction.In the composites, because of the forces that were applied on the rigid sisal fiber by rotor, polylactic acid melt and interaction among fibers, the sisal fibers were snipped and the length-diameter ratio decreased.In addition, polyactic acid degraded due to the effect of rotor speed and sisal fiber content.These factors affected the rheological properties of polylactic acid/sisal fiber composites.

Key words: 剑麻, 聚乳酸, 转矩流变仪, 流变性能, 长径比