| Bamboo is an important ecological and industrial resource in China,which has the advantage of light color,high strength and hardness,and strong toughness.At the same time,starch and sugar substances in the bamboo are rich in content,which are prone to mildew and decay during use,and bamboo has poor weather resistance durability,these disadvantages seriously restrict the high added-value utilization of bamboo resources.In this paper,alcohol-based resin was used to modify the bamboo bundles.The concentration of alcohol-based resin,catalyst type,impregnation pressure and time,curing time and temperature were studied systematically,and the effects of mildew resistance and mechanical strength were obtained.The optimized bamboo alcohol-based resin modification treatment process was obtained,and high-strength anti-corrosion reconstituted bamboo was prepared.The modification mechanism was revealed,in order to provide reference to utilize high value-added industrialization of bamboo.The main conclusions of this paper are as follows:(1)The influence of alcohol-based resin modification treatment process on the weight percent gain(WPG),color and mildew resistance of bamboo bundles was revealed,and an optimized modification treatment process was obtained.Studies have shown that the concentration of alcohol-based resin,the type of catalyst and the impregnation pressure have significant effects on the WPG and color of bamboo bundles,but the factors such as impregnation and curing time,curing temperature and medium type have little effects.Compared with the control material,the WPG of the modified bamboo bundles can reach 25.16%,the chromatic aberration(CA)can reach 67.29,the mildew resistance can be improved by 4 grades.20%concentration of the alcohol-based resin,the catalyst C,0.1 MPa impregnation pressure,1 h impregnation time,air curing medium,105? curing temperature and 3 h curing time were proposed as the optimization process parameters.(2)The effects of modification treatment of alcohol-based resin on the color,mechanical strength and mildew resistance of recombinant bamboo were determined,and high-strength anti-corrosion reconstituted bamboo was prepared.The results showed that the modification can significantly deepen the color and improve the mildew resistance.Compared with the natural reconstituted bamboo,the CA can reach 47.93,and the mildew resistance is improved by 3 grades.Compared with carbonized reconstituted bamboo,the internal bending strength,static bending strength and horizontal shear strength can be increased by 82.03%,164.25%and 36.72%,respectively.The mechanical strength can meet the requirements of the national standard superior products,and the control efficiency of mold can reach 100%.(3)The modification mechanism of bamboo alcohol-based resin was preliminarily described by means of infrared spectroscopy(FTIR)and X-ray photoelectron spectroscopy(XPS).The preliminary research results showed that the modification mechanism of bamboo alcohol-based resin was mainly reflected in two aspects:physical cover isolation and esterification acid degradation.On the one hand,the alcohol-based resin was formed a uniformly distributed film on the surface of the bamboo cell wall,which formed a covering effect on the bamboo substrate,and effectively separated the nutrients in the bamboo from the bacteria outside.On the other hand,in the modified esterification reaction,the starch and sugar substances in the bamboo were degraded under acidic conditions,and the source of nutrients of bacteria and mold was greatly reduced or cut off.It was the combination of these two aspects that the anti-mildew properties of the modified bamboo bundles and the reconstituted bamboo were significantly improved. |
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