【作者】 胡玉安；

【导师】 于文吉；

【作者基本信息】 中国林业科学研究院 ， 木基复合材料科学与工程， 2014， 博士

【摘要】 竹基纤维复合材料是以纤维化竹单板为基本结构单元按不同纹理方向经热压或者冷压胶合而成的竹质人造板材，因其具有优良的物理力学性能，可控的密度，在户外地板、家居装修材料上已得到了广泛的应用。目前，随着国际市场上对于竹质材料环保性能的认可，以及我国在竹基纤维复合材料制备技术上的突破，室外用重组类竹质材料的需求量与日俱增。开展重组竹质材料染色性能以及耐候性能的系统研究，对于扩展竹基纤维复合材料的应用领域具有极大的促进作用，对提升我国竹基纤维复合材料在市场上的整体竞争力、推广户外用竹基重组类产品、提高其产品的附加值具有重要意义。本论文主要以毛竹（Phyflostachys pubescens）为研究对象，以水、醇为介质，采用不同工艺对纤维化竹单板进行染色处理后，以浸渍型酚醛树脂为胶黏剂制备重组竹板材，并分析染色处理对竹基纤维复合材料的表观颜色指标及物理力学性能的影响。通过对染色处理后纤维化竹单板制备的竹基纤维复合材料进行室外自然老化的研究，探讨了室外自然老化与材料表面颜色及尺寸稳定性的关系，揭示了在室外老化环境下竹基纤维复合材料性能随时间变化的规律。主要研究结论如下：（1）对采用90℃水染、漂白后75℃醇染与20℃水染三种工艺手段，利用酸性黑2染料染色制备竹基纤维复合材料的物理力学性能研究发现，染色处理工艺采用醇类作为环境介质时，黑色竹基纤维复合材料的静曲强度、弹性模量、水平剪切强度降低，采用升温染色处理工艺方法制备的竹基纤维复合材料的静曲强度、弹性模量小幅降低。剪切强度减小幅度较大。此外，将采用染色处理工艺与未染色工艺制备的竹基纤维复合材料相比较，材料的耐水性能得到了提高。从竹基纤维复合材料的表观颜色来看，随着染色处理采用升温染色与醇溶剂媒介染色，竹基纤维复合材料的表面黑色泽明显加深。与未染色处理材料相比较，材料的明度指数L*值明显减小，表面由亮变暗，总色差值ΔE*ab明显增加。（2）对采用90℃水染、漂白后75℃醇染与20℃水染三种工艺手段，利用碱性棕G染料染色制备竹基纤维复合材料的物理力学性能研究发现，染色处理工艺采用醇类作为环境介质时，黑色竹基纤维复合材料的静曲强度、弹性模量与水平剪切强度出现降低，不同处理工艺对它们的影响差异显著。采用升温染色处理工艺方法制备的竹基纤维复合材料的静曲强度有所降低。染色处理工艺方法的改变对弹性模量造成的影响与对静曲强度的影响规律基本一致。此外，将采用染色处理工艺与未染色工艺制备的竹基纤维复合材料相比较，材料的耐水性能减弱。从竹基纤维复合材料的表观颜色来看，随着染色处理采用升温染色与醇溶剂媒介染色，竹基纤维复合材料的表面红色泽都明显加深。与未染色处理材料相比较，材料的明度指数出现减小。总色差值ΔE*ab明显增加。（3）竹基纤维复合材料经过3个月的室外自然老化试验过程后，从材料表面的颜色指标变化情况可以看出，随着气候条件的变化，材料表面色泽出现缓慢衰减趋势，随着染色处理温度的增加与室外放置时间时间的延长，L*值与a*、b*值的变化趋势放缓。另外，醇染制备的竹基纤维复合材料表面颜色变化趋势与水染制备的竹基纤维复合材料变化趋势一致规律，变化幅度也与水染竹基纤维复合材料无明显差距。不同染色方法制备的竹基纤维复合材料的宽度损失率、厚度损失率、质量损失率随着气候变化而具有一致的增减趋势，染色处理温度的升高有利于改善竹基纤维复合材料稳定性与耐候性。醇染竹基纤维复合材料的宽度、厚度、质量损失率均高于水染竹基纤维复合材料。（4）根据物理力学及耐久性能的研究结果，染色处理后竹基纤维复合材料物理力学性能未发生严重损失，材料的室外耐老化性能增强，表观色泽明显改善，具有较高的室外应用潜力。其中采用有机溶剂醇类作为染色环境介质是形成良好的色泽，提高产品尺寸稳定性耐久性能的关键因素。（5）在使用酸性黑2与碱性棕G对竹材进行染色时,通过对染色试件的光学显微镜可以清楚的观察到染色竹材横切面与径切面的维管束与薄壁组织细胞的染料上色情况，可以看出，，当采用醇类作为染色环境介质时，由于有机溶剂醇类的染料选择吸着较弱，从光学显微镜拍摄照片中可以观察到染色色泽优于采用水作为染色环境介质时制得的样品色泽。这说明了醇染对于提高竹材细胞的染色强度有着促进作用。通过对染色试件的扫描电镜观察，可以清晰地观察到染料分子竹材组织上出现不同程度的聚集分布现象，并且均呈小球状颗粒状附着在细胞腔的内壁以及纤维壁上。用扫描电镜还直观的观察到细胞纹孔与附近染料颗粒的的尺寸及其分布情况，电镜图可以说明酸性染料酸性黑2与碱性染料碱性棕G的颗粒或分子团束通过细胞纹孔进入竹材细胞壁对细胞壁形成上染是可的。更多还原

【Abstract】 As a bamboo-based panel made from bamboo fibrosis veneer, bamboo-based fiber composite is an economic wood-substitution and can utilize the small-diameter bamboo efficiently. Because of its controllable density and other excellent physical/mechanical properties， bamboo-based fiber composite products have been widely used as indoor flooring furniture and decoration materials. However, with the breakthrough of bamboo-based fiber composite manufacturing technology, the demand for outdoor reconstituted bamboo lumber wasalso increasing and thus the lumber’s durability has become a research focus. Systematic research on the dyeing properties, weather resistance properties of bamboo-based fiber composite will be important for satisfying the demand for product diversification and providing the reference for research and production of bamboo-based fiber composites, and promoting its outdoor application and increase its added value.In this paper, Phyflostachys pubescens bamboo fibrosis veneer were chosen as basic raw materials. They are dye-treated with different method, and then reconstituted with phenol-formaldehyde adhesive and hot pressing process. The effect of dye-treatment on the physical, mechanical properties and surface color of bamboo-based fiber composite were studied. The properties of dye-treated bamboo-based fiber composite after outdoor aging test were analysed, the relationship between of outdoor aging test time and surface color, dimensional stability, weight loss rate were also discussed. The main results were summarized asfollows:（1） The surface color turned from light to dark as the dye-treated temperature and time increase. After applying the dye-treated method, the MOR and shear strength (parallelloading) are slightly reduced compared with the untreated specimens. The thickness swelling rate and water absorption rate of bamboo-based fiber composites were also increased by the dye treatment. According to the study, we also found that the bamboo fibrosis venee r dyed in alcohol at75°C and those dyed in water at90°C had a higher exhaustion rate than those dyed in water at20°C.（2）After3months’ outdoor aging test, the change of color, ΔL*、Δa*、Δb*valuewas declined gradually with the increase of the outdoor aging test time. The changes in dimensional stability and weight loss rate have shown similar trends with the time under different climate conditions.（3） According to the study, the physical, mechanical, and color properties of bamboo-based fiber composites (Phyflostachys pubescens) are all influenced by the presence of dyeing treatment. Remarkable colour changes were observed after dye treatment when the bamboo was dyed in alcohol source at75°C, while the MOR, MOE and shear strength (parallel loading) didn’t change much after the dye treatment. Therefore, we think that it is the optimum selection when the bamboo was dyed in alcohol source at75°C.（4） According to the study, a remarkable increase in color was observed in the bamboo’s transverse section and radial sections. We can observe that the vascular bundleof bamboo in the transverse section was nearly completely red. From the radial section,We can also observed that the color of fibers was nearly completely redder than the color of bamboo parenchymatous cells. In addition, the color of treated in alcohol was slight redder than the color of bamboo treated in water. This result shows that the method of dyeing in alcohol was helpful for improving the color strength.（5）The images of dyed raw bamboo culm and untreated raw bamboo culm withbasic grown G and acid black2by SEM are depicted in chapter6. The untreated rawbamboo culm sample had a comparably smooth surface, and the image of the dyed raw bamboo culm sample indicate that dye accumulate on the surface of fiber cell as afine spherical particle. The result indicate that dye particle size not larger than1μm. We can also observe the pit diameters in cells of approximately3to10μm, These results can be regarded as indicating that there was a favorable factors for the water-solublebasic dye molecules removed into the cell wall bamboo from pit.更多还原