Preparation And Properties Of Copper Anchored By Silica Gel Anti-mold Chemical Used For Bamboo

With timber resource becoming increasingly scarce in our country, bamboo materials of abundant, short production cycle, and renewable is becoming the important wood raw material. However, bamboo are more prone to mildew, bluestain, worm-eaten and rotten in the storing, transportation and use of the process due to abundant nutrients, such as carbohydrate, starch, protein, fat and so on. These had badly affected the processing and utilization of bamboo, and even caused great economic loss. Therefore, the research progress and advance manufacture methods in this field at home and abroad were summed up. Based on this, Moso bamboo (Phyllostachys pubescens), which is abundant in China, was used as experimental materials in this thesis. For the first time, copper anchored by silica gel anti-mold chemical was prepared in this study, and the bamboo treatment process of anti-mold chemical was explored and the mold-resistant performance of anti-mold chemical treated bamboo was evaluated. Moreover, the anti-mold chemical distributed in bamboo was characterized by SEM-EDS, variation binding ways and functional groups among the treated samples were detected through FTIR and XRD. Micro structure of the anti-mold chemical treated samples were characterized by SEM. Meanwhile, variation functional groups in the treated and untreated bamboo mildewed before and after were investigated by FTIR. The fixation mechanism, protection, and approach for formulation optimization of anti-mold chemical have been proposed. The main research findings were summarized as follows:(1) Inhibition circle test was used to evaluate antibacterial properties for anti-mold chemicals and its single component. The results showed that the type and the concentration of chemicals, as well as the variety of strains greatly influenced on diameter of the inhibition circle, which is growing with the increasing of chemicals concentration and proportion. The best formulation is3:5:10, which are TEOS, anhydrous ethanol, and pure water, respectively.(2) The best processing condition was confirmed by anti-mold chemicals treating. The pressing time was90min, the pressing temperature was125℃(corresponding pressure was0.185MPa), and anti-mold chemical concentration was3.00%. After the anti-loss experiments, leaching formulation (LF) of bamboo treated with copper anchored by silica gel anti-mold chemical was CCA’s1/3and ACQ’s1/5. Silicone gel improves the fixation performance of copper in bamboo.(3) SEM-EDS analysis showed that the first path of fungicide into the bamboo is pipe, cell gap, then the other organizational structures of bamboo, such as screens, bamboo fiber cells. FTIR analysis showed that copper fungicide and carboxyl groups which come from bamboo cellulose, hemicelluloses can react and generate carboxylic acid with copper. It is also form hydrogen bonds between the bamboo and fungicide. Copper fungicide can be setted by the way of physical adsorption, such as van der waals force. XRD analysis showed that compared with the untreated bamboo, the position of the diffraction peak of anti-mold chemical treated samples have not changed but the intensity reduced and the anti-mold chemical dipped in bamboo have not changed the structure and interplanar spacing of cellulose while affecting the crystallinity of bamboo.(4) The evaluation results of anti-mildew performance showed that all the mold damaged value of bamboo were less than1after treated by chemicals concentration of1.00%,3.00%, and5.00%; The anti-fungal effectiveness of bamboo was100.00%treated with copper anchored by silica gel, when the concentration reached3.00%. However, when the concentration of ACQ or CCA reached5.00%, the same anti-fungal effectiveness was achieved. It means that the anti-fungal effectiveness of copper anchored by silica gel was better than that of ACQ and CCA to some extent; The effectiveness of same kind of mildew on different strains were various; The strains used in this study had the best effectiveness on the orange penicillium and the worst effectiveness on the blue stain fungi.(5) The catheter was the main passageway of fungal hyphae spreading in bamboo. The mildews were first emerged in the catheter, then the other organizational structures, such as bamboo parenchyma cells and screens, etc. The small parts of lignins, hemicelluloses and other components were decomposed gradually after the mold got into the bamboo. The silica gel fixed with copper fungicide can effectively prevent the components of bamboo from mold eroding during the course of bamboo mildew.