Effect of alkoxysilane treatment on dimensional stability of poplar
As well known,methyltrimethoxysilane(MTMS)is effective to improve decay resistance and dimensional instability.However,its treatment process and suitable dosage have not been studied thoroughly.The aim of this ex-periment was aimed at exploring the effect of solvent systems on the dimensional stability of poplar after treatment with alkoxy silanes.Using 5,10 and 15 g propyltrimethoxysilane(PTMS)compounded with 15,10 and 5 g MTMS,respectively,poplar samples were treated by the gas-assisted migration method,and the changes of density,mass in-crease rate,contact angle and dimensional change were investigated.The results showed that,with 50％PTMS,the water absorption of the treated wood was 27.3％after 7 d of immersion in water at room temperature.The water con-tact angle of the treated wood was(125.3±1.3)°.Moreover,the higher the mass ratio of PTMS and the lower the mass ratio of MTMS in the solution system,the smaller the mass increase rate and density growth,and the better the hydrophobicity.The PTMS mass ratio was positively correlated with the increase in hydrophobicity of the treated wood,while the dimensional stability was reduced when the PTMS mass ratio was too high or too low.The possible reason was that MTMS and PTMS had different mechanisms to improve wood properties,of which the higher the mass fraction of small molecules of MTMS,the easier it was to penetrate wood cell walls,thus forming a crosslinked network to support the cell wall structure,which was conducive to the improvement of the modified wood properties such as decay resistance and dimensional stability.PTMS and its modified alkoxysilane formed by the low surface energy of the crosslinked network to penetrate through the cell wall resistance,partially existed outside the cell walls,which had a greater impact on water exchange.The low surface energy crosslinked network formed by PTMS and its modified alkoxysilanes had a higher resistance to penetrate cell walls,and part of it existed outside the cell walls,which had a greater effect on water exchange.This study showed that the properties of wood modified by PTMS/MT-MS gas-assisted migration were related to the solution system.According to the data,the use of 1∶1 PTMS and MT-MS compounding was a more suitable mixed solution system.It was appropriate to customize the dosage of the modi-fier to the volume,mass and moisture content of the wood.
国家科技期刊平台
NSTL
万方数据
维普
