PMDI-PVAc用于无醛刨花板制备研究

Study on Preparation of the Aldehyde-Free Particleboard with PMDI-Polyvinyl Acetate Emulsion

采用多亚甲基多苯基多异氰酸酯(PMDI)和聚醋酸乙烯酯(PVAc,俗称白乳胶)作为无醛胶黏剂、乳化石蜡作为防水剂制备无醛刨花板,探讨了添加白乳胶、施胶配比、石蜡添加量对刨花板性能的影响。结果表明,生产无醛刨花板时,在表芯层采用PMDI和白乳胶复合施胶的方案可以提高板材的板面质量和耐水性;表层的施胶量为PMDI 5 kg/m^(3)、白乳胶30 kg/m^(3)、石蜡添加量为绝干刨花质量的1%,芯层施胶量为PMDI 10 kg/m^(3)、白乳胶5 kg/m^(3)、石蜡添加量为1%时的刨花板综合性能相对较优;在一定范围内,提高石蜡添加量可以适当提高板材的耐水性。

In this study,the aldehyde-free particleboard was reported by utilizing PMDI and polyvinyl acetate emulsion(PVAc)as aldehyde-free adhesives,and emulsified paraffin as waterproofing agent.The effects of PVAc amounts,adhesives ratios and paraffin additions on physical and chemical properties of the particleboard were analyzed.The results indicated that the surface quality and water resistance of the particleboard could be enhanced by combining PVAc and PMDI in both the surface and core layer.When the sizing amount of the surface layer was 5 kg/m^(3) PMDI,30 kg/m^(3)PVAc and wt 1%paraffin(relative to oven-dried wood shavings),and the sizing amount of the core layer was 10 kg/m^(3) PMDI,5 kg/m^(3)PVAc and wt 1%paraffin(relative to oven-dried wood shavings),the particleboard exhibited relatively high comprehensive performance.In addition,the water resistance of the particleboard could be improved by increasing paraffin additions within a certain range.