Mechanical and Morphological Properties of Wood Plastic Biocomposites Prepared from Toughened Poly（lactic acid） and Rubber Wood Sawdust （Hevea brasiliensis）

The present research aims to utilize the acrylic Core-Shell Rubber （CSR） particles to reduce the brittleness in Wood Plastic Composites （WPC） prepared from poly（lactic acid） （PLA） and rubber wood sawdust （Hevea brasiliensis）. Experimental works consisted of two major parts. The first part concentrated on toughening PLA by using CSR particles. Mechanical tests revealed that PLA had become tougher with a more than five times increment in the impact strength when the CSR was added at only 5 wt%. The modified PLA was less stiff with the significant reductions of both elastic and flexural moduli and strengths. The second part focused on producing WPC from the toughened PLA and rubber wood sawdust. The tensile moduli and the strengths of the PLA composites increased with rubber wood content. The composites turned out to be more brittle with reductions of both the impact strength and the tensile elongation at break at all the sawdust contents. Toughening PLA/wood flour with 5 wt% CSR improved both the impact strength and the tensile elongation at break. The toughness enhancement was also depicted by the plastic deformation observed on the surfaces of fractured PLA/CSR/wood sawdust composites.

桑枝与橡胶木屑栽培白背木耳配方筛选

通过不同配比的桑枝、橡胶木屑、麸皮及玉米粉的配方筛选,比较各配方对白背木耳菌丝生长状况、鲜重和生物学效率的影响。结果表明,桑枝务39.5%、橡胶木屑38.5%、麸皮10%、玉米粉10%、石膏0.5%、石灰0.5%、白糖1%为最佳的配方,鲜重达1.04kg生物学效率达103.88%,且菌丝生长势旺、洁白、粗壮、整齐,生物学效率较高。因此生产上运用此配方栽培白背木耳可行。

橡胶木屑基活性炭—聚氨酯复合材料的制备及其微波吸收性能（英文）

采用ZnCl2对橡胶木屑进行化学活化制备出活性炭。ZnCl2与橡胶木屑的浸渍质量比为1.0-2.0,活化温度为500℃,时间为60min。通过扫描电镜、X射线衍射和BET比表面分析仪探讨浸渍比例对活性炭孔结构的影响。结果表明,当浸渍比为1.5∶1时,样品的比表面积和孔径分别为1301m2/g和0.37cm3/g。通过化学发泡工艺将不同质量分数(1%,2%,3%,5%,8%)的活性炭填充至聚氨酯中制备出聚氨酯复合材料。在1-5GHz频率范围内,复合材料吸收微波。随着活性炭含量增加,在1-3GHz范围内,介电常数(ε’)和回波损耗增加。活性炭含量为8%时复合材料的介电常数达到最大值3.0。在1.8GHz时,复合材料的回波损耗为10dB。在-2.5GHz,电磁屏蔽效率大于3dB。与传统聚合物材料如填加金属的聚氨酯和聚酯相比,所制复合材料呈微波段吸收,可作为电磁屏蔽材料。