Study On Physical And Mechanical Properties Of Bamboo Scrimber Improved By Si-Al Sol-Gel

The bamboo scrimber is a new bamboo product with independent intellectual property rights.It makes full use of the advantages of the abundances bamboo resources in China.This material shows good properties in heat insulation and superior seismic,and is a remarkable renewable and recycling material.The applications are widely,not only as floor boards used in the indoor and outdoor,but can be applied in the bridge construction area as engineering material.Just because bamboo fibers contain lots of carbohydrates,starch and protein substances,causing the material's water resistance is poor,resulting in bad performance of the material's size stability,which finally reduces the application of bamboo scrimber greatly.Therefore,aiming at solving the problem of poor dimensional stability of bamboo scrimber,the inorganic fillers of aluminum sulfate and sodium silicate were used to synthetize composite which prepared by sol-gel.Comprehensive research was mained on the preparation process,the distribution of silicon and aluminum inorganic substances in the bamboo scrimber materials,the interface combination and performance modification of them.The preparation process of the modified silica sol-gel was discussed by a single factor test design.The influence of two factors is the Si/Al mole ratio and the pH value,which were mainly investigated.The preparation process for optimizing the silicon aluminum sol-gel for the bamboo scrimber is:Si/Al mole ratio is 11.5:1 and the pH value of is 6.0.The sample's shearing strength is 15.1 MPa,MOR is 120.7 MPa,MOE is 13.8 GPa.By using the response surface method,the optimized process parameters of organic-inorganic compound bamboo scrimber material are:Si/Al mole ratio is 11.5:1,hot pressing time 1.33 min/mm and hot pressing temperature 165 ?.Through this way,the thickness swelling rate of the plate is 1.53 ± 0.20%,MOR is 125 MPa,MOE is 14.3GPa.For explaining the mechanism of combination between bamboo material and the silicon aluminum sol-gel,and for understanding the functional group of the bamboo scrimber material,the microstructure and the distribution of inorganic elements on the surface of bamboo scrimber was measured by SEM,XPS,FTIR and the thermal analysis respectively.The results showed that:the bamboo scrimber material contained Si-O-C and Al-O-C chemical bonds,and because of their reaction,the Si-Al inorganic compound would form in the bamboo fiber's surface and inside.Through the SEM,we could find that the surface of bamboo fiber was covered by the film and because of the influence of it,bamboo fibers could adhesive tough and formed an efficient network structure.Three coalescent modes between bamboo fibers and sol-gel In conclusion were found.One was hydrogen bonding,another was Si-Al sol-gel filled in the bamboo fibers cell and the last is through covalent bonding,like Si-O-C and Al-O-C.Si-Al inorganic phrase can build effective interaction with bamboo fiber organic phrase.