重组竹流体渗透性机理研究

Bamboo scrimber is a novel bamboo based composite made from bamboo bundles compressed, modified and bonded in parallel direction. It becomes one of the main commercial bamboo products in Jiangxi. Physical and chemical and colour changes of bamboo cells such as compressing, bonding and densifying take place during the forming process of bamboo scrimber, which influence directly the performances of bamboo scrimber such as density, mechanical strength and water swelling rate. The existent study mainly focus on the forming technology, however, it would restrict the further development of industry for bamboo scrimber owing to the lack of systematic theoretical study. The response mechanism of bamboo cell wall and the formation mechanism of adsorbion are the key scientific problems during bamboo scrimber forming process. Therefore, in this proposal, the bamboo scrimbers are fabricated via both dyeing process and carbonization processes. In addition, several analytical techniques such as small-angle X-ray scattering (SAXS), micro computed tomography (Micro CT) and transmission electron microscopy (TEM) are employed to investigate the cell structural changes as well as chemical, physical and mechanical properties, and to study the penetration, wettability and curing phenomenon of phenolic resin on the bamboo bundles, and then to explore the compatibility, interaction and adsorbion properties between bamboo cell and dye or water. Finally, the response mechanism of cell wall and the adsorbion formation mechanism of two methods will be revealed and then their effects on the physical and mechanical properties of bamboo scrimber will be also studied. The results of this fundamental work have a promise to provide a theoretical basis for solving the common problems in the industry of bamboo scrimber such as dimensional stability and performance modulation.

重组竹是将竹材疏解成竹束再经改性处理，铺装组坯，热压后通过胶黏剂胶合制成的竹基纤维复合材料，是江西省竹材利用的首要产品。在重组竹生产过程中，竹材细胞在改性处理时发生颜色、性能改变等物理化学变化，直接影响产品的密度、强度、吸水膨胀率性能，目前的研究主要集中在生产工艺技术，缺乏系统的理论研究，制约了产业的再发展。两种预处理的核心科学问题是湿热作用下细胞壁响应机制及吸附界面形成机理。本项目以染色和炭化两种改性方法制备的重组竹为研究对象，采用SAXS、Micro CT、TEM 等先进设备，研究重组竹细胞壁的构造、化学组分和物理力学性能及变化规律；研究染液与水蒸气两种流体在竹束中的渗透、润湿、附着及与细胞壁的相容性、吸附界面结构。阐明两种预处理方法细胞壁的响应机制，揭示细胞壁与吸附界面形成机理，探索其对重组竹物理力学性能的影响机制，为解决重组竹尺寸稳定性和性能调控等制约产业发展的共性问题提供理论依据。

本项目以毛竹（Phyllostachy spubescens）、寿竹（Phyllostachys bambusoides f.shouzhu Yi）两种竹种和低分子量酚醛树脂为主要研究对象，采取染色处理和碳化处理两种处理方法，对纤维化竹单板进行处理，再利用施胶、热压后的处理竹束制备不同密度的重组竹，以不同的组坯方式与施胶量为主要研究对象，研究施胶量、组坯方式对寿竹竹基纤维复合材料的静曲强度、弹性模量、吸水厚度膨胀率与水平剪切强度等性能的影响。研究纤维化竹单板处理前后细胞壁的微观构造、化学组分、胶合界面和物理力学性能变化规律，揭示了重组竹材料在染色及碳化改性过程中竹材微观结构对渗透效应的差异响应作用机制，建立了新型竹基纤维复合材料流体渗透性适用研究方法，为解决重组竹尺寸稳定性和性能调控等制约产业发展的共性问题提供理论依据，为竹重组材材料的合理推广应用提供理论参考。