Study On The Change Of Structure And Chemical Composition Of Bamboo During Softening And Flattening

The softening and flattening technology can effectively increase the utilization rate of bamboo,but the basic theory still needs to be studied.The paper is to study on the changes of bamboo components,Macro-and Micro-Structural during the process of softening and flattening.The dynamic mechanical analyzer(DMA)was used to study the glass transition temperature(Tg),storage modulus and loss modulus of Phyllostachys edulis bamboo.Research showed that :(1)It is very obvious that the main chemical components were affected by the softening.compared with bamboo softened board,there was no obvious influence on the chemical composition after flattening.After the softening process,the content of lignin was increased,and the content of holocellulose and α-cellulose was reduced.(2)Softening and flattening treatment have different effects on the internal structure of bamboo.After the softening,the distance between the crystal layers of the crystalline region of the bamboo was not changed,and the cell shape change was small.The density of the bamboo material decreased,the porosity increased,and the pore size of the mesopores increased,but the change was not obvious.(3)The thickness of the bamboo wall was reduced to varying degrees during the process of softening and flattening.The more reduction of the bamboo wall after the softening,the less flat crack rate and the higher success rate.There is a certain relationship between the change of wall thickness and the ratio of wall to cavity in bamboo.The flat plate crack rate increases as the ratio of wall to cavity increases.Removal of bamboo-green treatment had no significant effect on the change of bamboo wall thickness.The removal of bamboo green treatment can reduce the crack rate of bamboo flattening board and improve the quality of the panel.(4)The softening and flattening have a great influence on the glass transition temperature,storage modulus and loss modulus of bamboo.At room temperature,the storage modulus of bamboo and bamboo flat plates is significantly greater than that of untreated bamboos.The loss modulus showed softened bamboo> bamboo panel> Untreated bamboo raw bamboo.Tg of softening and flattening bamboo were lower than the Untreated bamboo.