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.     

聚对二氧杂环己酮─乙交酯无规共聚物缝合线热处理及体外降解性能研究

本文研究了热处理对聚对二氧杂环己酮-乙交酯无规共聚物合成缝合线力学性能和体外降解性能影响。结果表明：60～80℃温度范围内定长热定型对缝线原有力学性能影响较小；体外降解性能表明，随着热定型温度提高，缝线强度下降速率减缓。DSC测试结果表明，热定型后缝线样品结晶度提高，体外降解过程样品结晶度也逐渐提高，其中，无热定型样品提高幅度最大，说明热定型可使缝线样品聚集态结构紧密，水解速度减慢。     

氯磺酸磺化PE非织薄膜及表征

通过磺化反应改善聚乙烯(PE)非织薄膜的亲水性,考察了时间、温度、物料配比等条件对磺化反应的影响,并用红外光谱(FT-IR)、X射线能量色散谱(EDS)及扫描电镜(SEM)对产物进行了表征,同时对PE非织薄膜的亲水性和力学性能进行了测定。结果表明:通过氯磺酸磺化可以将—SO3H基团引入PE大分子,磺化后的PE链段互相聚集无序堆砌形成微小颗粒;PE非织薄膜的断裂强度随磺化反应程度的增加而下降。