How to improve mechanical properties of polylactic acid with bamboo fibers
How to improve mechanical properties of polylactic acid with bamboo fibers
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DOI：
10.1007/s10853-007-1994-y
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发表时间：
2008-01-01
影响因子：
4.5
通讯作者：
Fujiura, Takayasu
中科院分区：
文献类型：
--
作者：
Tokoro, Ryoko;Vu, Duc Minh;Fujiura, Takayasu
将竹纤维（BF）与聚乳酸（PLA）共混，以提高PLA的冲击强度和耐热性。采用氢氧化钠（NaOH）处理和蒸汽爆破结合机械加工的方法从竹材中提取三种不同类型的BF。它们分别被命名为“短纤维束”、“碱处理长丝”和“蒸汽爆破长丝”。采用双螺杆挤出机制备PLA/BF复合材料，通过注射成型制备复合材料。其中，蒸汽爆破丝加入聚乳酸基体中的弯曲强度最高。加入短纤维束和两种长丝对PLA的冲击强度没有明显的改善。为了提高PLA/BF复合材料的冲击强度，采用中长竹纤维束（MFB）交替热压制备PLA/BF复合材料试样，以避免纤维长度在制备过程中的下降。PLA/MFB复合材料的冲击强度显著提高，其中长纤维束从基体中拔出。BF的加入改善了PLA/BF复合材料的热性能和耐热性，这是由于PLA的变形受到限制以及退火（在110 ℃下5 h）促进的结晶度。
Bamboo fibers (BF) were mixed in polylactic acid (PLA) to improve its mechanical properties: impact strength and heat resistance. Three different types of BF were extracted from raw bamboo by either sodium hydroxide (NaOH) treatment or steam explosion in conjunction with mechanical processing. They were designated as "short fiber bundle," "alkali-treated filament" and "steam-exploded filament," respectively. Composite samples were fabricated by injection molding using PLA/BF pellets prepared by a twin-screw extruding machine. Among them, the highest bending strength was obtained when steam-exploded filaments were put into PLA matrix. Impact strength of PLA was not greatly improved by addition of short fiber bundles as well as both filaments. In order to improve the impact strength of PLA/BF composites, PLA composite samples were alternatively fabricated by hot pressing using medium length bamboo fiber bundles (MFB) to avoid the decrease in fiber length at fabrication. Impact strength of PLA/MFB composite significantly increased, in which long fiber bundles were pulled out from the matrix. The addition of BF improves thermal properties and heat resistance of PLA/BF composites due to the constraint of deformation of PLA in conjunction with crystallinity promoted by anneal (at 110 degrees C for 5 h).