Study On The Process And Performance Of Acetic Acid Combined With Hydrogen Peroxide Softening Treatment Of Moso Bamboo Material

Bamboo wood is not suitable for direct application in the production of pencil boards due to its large hardness and other performance indicators.Therefore,softening of moso bamboo timber is carried out to replace the existing linden wood and other timber for pencil manufacturing in order to alleviate the problem of wood resource tension and promote the development of bamboo industry.In this thesis,we used the full-factor experimental method to analyze the influence of softening factors on the properties of moso bamboo timber,explore the softening process of bamboo pencil boards,study the changes of flexural modulus of elasticity,smooth grain tensile strength and hardness of moso bamboo timber before and after softening,compare its dimensional stability and surface material color;explore the microscopic morphological changes of moso bamboo timber before and after softening,use XRD and FTIR to analyze the cellulose crystallization properties and lignin,cellulose and The dynamic viscoelasticity and nanomechanical properties of thin-walled cells were investigated by XRD and FTIR.The main conclusions are as follows:(1)The softening process of moso bamboo with acetic acid and hydrogen peroxide showed that the flexural modulus of moso bamboo decreased by 39.84%,44.42% and 48.88% at 60%,70% and 80%of acetic acid concentration,respectively,compared with the control group,which increased and then decreased with the increase of hydrogen peroxide concentration and decreased with the increase of softening temperature.The softening process was preferred: FM: softening at 70°C for 24 h,acetic acid concentration 80%,hydrogen peroxide concentration 0%;SM: softening at 80°C for 36 h,acetic acid concentration 70%,hydrogen peroxide concentration 3%;TM: softening at 60°C for 48 h,acetic acid concentration 60%,hydrogen peroxide concentration 6%.hydrogen peroxide concentration 6%.(2)The study of different moso bamboo parts treated with the above three preferred softening processes showed that the physical and mechanical properties of the moso bamboo material showed an increasing trend from the root to the tip;the change of mechanical properties of the moso bamboo material was more obvious in SM,and the flexural modulus of elasticity,smooth tensile strength and hardness decreased by 22.67%,38.01% and 38.97%,respectively;the dimensional stability of the moso bamboo material in the root part decreased the least after softening The softening process was preferred for the middle part of the moso bamboo material SM,while the softening process was preferred for the root and tip parts TM.(3)Microstructural and compositional analysis of moso bamboo timber before and after softening showed that the hardness and elastic modulus of thin-walled cells of moso bamboo timber decreased after softening,and the decrease was gradually reduced from the root to the tip;the cell walls of thinwalled cells of moso bamboo timber were partially discrete and swollen to a greater extent,and starch disappeared,but the overall microscopic morphology was well maintained;storage and loss modulus decreased with the increase of moso bamboo timber parts,and decreased with the increase of testing temperature;from the root to the tip The Tg of the softened moso bamboo lumber decreased from root to tip,indicating a good softening effect;the three major elements of moso bamboo lumber were partially degraded and the relative crystallinity decreased after softening.