蔗糖与二羟甲基二乙烯脲浸渍压缩杨木单板的性能评价

Properties of Compressed Poplar Veneer Impregnated with Mixing Solutions of Sucrose and DMDHEU

以蔗糖为细胞壁充胀剂,二羟甲基二乙烯脲(DMDHEU)为交联剂对速生软质杨木单板进行浸渍处理和热压固化定型,通过细胞壁化学改性和细胞腔物理压缩协同作用,实现低载药量下单板的密实增强。系统评价了蔗糖和DMDHEU浸渍压缩对所制备单板的回弹率、密度、硬度、表面颜色和力学强度等物理力学性能的影响。结果表明:5%蔗糖和10%DMDHEU浸渍压缩的杨木单板经5个水饱和—干燥循环和1次水煮测试后压缩回弹率为23%,表面密度提高至0.71 g/cm3,达到硬质阔叶材水平,表面硬度比素材增加2倍,单板颜色从暗灰色变为明亮的金褐色,水性涂料在浸渍压缩表面的漆膜附着力显著提高。综上所述,低质量分数蔗糖和DMDHEU浸渍压缩后的杨木单板具备作为复合地板优质表板的潜能。

We used the solutions containing both sucrose acting as cell wall bulking agent and 1,3-dimethylol-4,5-dihydroxyethyleneurea（DMDHEU） as cross-linking agent to impregnate veneers of poplar wood（Populus adenopoda Maxim） veneer that was hot-pressed thereafter to fix the deformation.The properties of the veneers were enhanced at low chemical loadings by chemical modification of cell walls and physical compression of cell lumens.We determined the effects of impregnation /compression on the properties of the resulting veneers,such as spring ratio,density,hardness,color,and mechanical strength.The compressed veneers treated with 5% sucrose and 10% DMDHEU exhibited 23% recovery ratio after five water saturation / oven drying cycles and one water boiling step.The density at the surface of compressed veneer reached 0.71 g /cm3 with high dense hardwoods.The treated and compressed veneers had a surface hardness as much as two times of the untreated / uncompressed control.The color changed from initial dark grey to golden brown.The adhesion of two waterborne coatings on the treated / compressed veneers was considerably improved compared to that on the untreated / uncompressed control.Therefore,there is a potential application of the treated / compressed poplar veneers at low chemical loading for the qualified surface layer of laminated floor.