It is frequently observed that bamboo particle composites (BPCs) do not show higher mechanical performances than the corresponding wood particles composites (WPCs), although bulk bamboo is much stronger than wood in mechanical performances. Herein this phenomenon was demonstrated from the cell compositions in the applied bamboo particles. To address that, a simple method to physically separate bamboo fibers (BFs) and bamboo parenchyma cells (BPs) from a bamboo particle mixture was developed. Polypropylene (PP) composites with pure BFs, BPs, a mixture of BFs and BPs (BFs + BPs), wood particles (WPs) as fillers were prepared. The flexural and dynamic mechanical properties, water absorption, and thermal properties were determined. The BF/PP composites showed the best mechanical performances (MOR at 35 MPa, MOE at 2.4 GPa), followed by WP/PP, (BF + BP)/PP, and BP/PP. They also exhibited the lowest water absorption and thickness swelling. Little difference was found for the thermal decomposition properties. However, a lower activation energy of BF/PP compared with BP/PP implied an uneven dispersion of BFs and weaker interfacial interaction between BF and PP. The results suggest that the mechanical performances and water resistance of bamboo particle/polymer composites can be significantly improved through cell separation. However, interface modification should be applied if higher performances of BF/PP composites are required.

中文翻译：

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通过细胞分离提高竹颗粒增强聚丙烯复合材料的机械和耐水性能

经常观察到，尽管散装竹的机械性能比木材强得多，但竹颗粒复合材料（BPC）的机械性能却不比相应的木颗粒复合材料（WPC）高。在此，从涂布的竹粒子中的细胞组成证明了这一现象。为了解决这个问题，开发了一种从竹颗粒混合物中物理分离竹纤维（BFs）和竹实质细胞（BPs）的简单方法。制备了具有纯BF，BP，BF与BP的混合物（BF + BP），木材颗粒（WP）作为填料的聚丙烯（PP）复合材料。确定了挠曲和动态力学性能，吸水率和热性能。BF / PP复合材料表现出最佳的机械性能（35 MPa时的MOR，2.4 GPa时的MOE），其次是WP / PP，（BF + BP）/ PP和BP / PP。它们还表现出最低的吸水率和厚度溶胀。发现热分解性质几乎没有差异。但是，与BP / PP相比，BF / PP的活化能较低，这意味着BFs的分散不均匀，并且BF和PP之间的界面相互作用较弱。结果表明，通过细胞分离可以显着改善竹颗粒/聚合物复合材料的机械性能和耐水性。但是，如果需要更高性能的BF / PP复合材料，则应进行界面改性。与BP / PP相比，BF / PP的活化能较低，这意味着BFs的分散不均匀，并且BF和PP之间的界面相互作用较弱。结果表明，通过细胞分离可以显着改善竹颗粒/聚合物复合材料的机械性能和耐水性。但是，如果需要更高性能的BF / PP复合材料，则应进行界面改性。与BP / PP相比，BF / PP的活化能较低，这意味着BFs的分散不均匀，并且BF和PP之间的界面相互作用较弱。结果表明，通过细胞分离可以显着改善竹颗粒/聚合物复合材料的机械性能和耐水性。但是，如果需要更高性能的BF / PP复合材料，则应进行界面改性。