Research on Flax Fiber Reinforced Polylactide Environmental Friendly Composite

Biodegradable polylactide acid （PLA） resin can be combined with flax fibers to produce biodegradable composite materials. In our study, commercial PLA fibers were mixed with flax fibers by a non-woven method so as to make non- woven pre-forms, which can be generated into flax fiber reinforced PLA environmental friendly composites by heat pressing technology. The tensile, flexural and impact properties are tested in order to evaluate the basic physical properties of the composites, and the influenced factors listed as making technology of the pre-forms, weight ratio of flax fibers and heat pressing technology are discussed and optimized, which can be described as weight ratio of flax fibers and PLA fibers is 50/50, heating temperature, time and pressure are respectively 195℃, 20 rain and 12.5 Mpa. Preliminary results show that mechanical properties of the flax/PLA composites are quite promising compared with flax/PP composites in coclrnon commercial automotive use. Scanning electron microscope （SEM） is used to analyze the tensile specimen fracture surfaces, which shows voids and gaps occurring between flax fibers and PLA matrix and sign of fiber pull.out, the strength of flax/PLA interface can be further improved.     

聚对二氧环己酮医用可吸收缝合线纺丝工艺研究

以聚对二氧环己酮为原料熔融纺制缝合线,研究了纺丝工艺对缝线的性能影响,结果表明,在室温和80℃进行两次拉伸所得缝线力学性能比较理想;70～100℃进行定长热定型,可在非晶区形成明显的微晶结构;在理想的工艺条件下纺制的缝线力学性能达到美国药典第22版要求.