改性水溶性聚氨酯的固沙促生性能及其机理  

Performances and mechanism of sand fixation and growth promotion based on modified hydrophilic polyurethane

作　　者：梁止水[1] 吴智仁[2] 

机构地区：[1]东南大学土木工程学院,南京210096 [2]江苏大学环境与安全学院,镇江212013

出　　处：《农业工程学报》2016年第22期171-177,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：十二五科技支撑计划项目(2013BAC05B02);江苏省普通高校研究生科研创新计划资助项目(KYLX15_0083)

摘　　要：为探明改性水溶性聚氨酯(W-OHC)固沙促生机理,采用室内试验,研究其固沙的渗透性能、抗压性能、表面硬度、抗风蚀性、抗冻融性、保水性能等基本性能,并开展室外试验进行验证。结果表明,W-OHC在沙表面具有良好的渗透性,当W-OHC浓度为3%时,渗透厚度可达到14 mm。固沙层抗压强度随着浓度增加逐渐增大,最大可达到1.27 MPa,表面硬度随着W-OHC浓度增加呈增大趋势,可达到23.2 mm以上,且抗风蚀效果良好,浓度为3%、喷洒量为3 L/m2时,固沙层可抵抗25 m/s的风速侵蚀而7 min内表面基本不发生变化,在50次冻融循环条件下,抗压强度和表面硬度的损失率10.2%和6.5%。W-OHC溶液固化后形成空间网状结构,可以起到很好的保水促生作用,相同条件下的水蒸发率降低50%以上,可大大延长干旱条件下植被的生长周期,提高植被恢复的效率。室外验证表明,3%W-OHC喷洒的试验区2 a后的植被覆盖率可达85%。研究为W-OHC在防风固沙方面的规模化应用提供理论和技术支撑。In order to study the mechanism of sand fixation and growth promotion by modified hydrophilic polyurethane （W-OHC）, experiments both in laboratory and in field were conducted. In the laboratory experiment, the sand was taken from flowing sand dunes around Qinghai Lake. The permeability of W-OHC on sand was tested through the free infiltration method and the penetration thickness was gauged by a plastic ruler （precision accuracy of 2 mm）. The performance of compressive strength of the sand-fixing layer was assessed in accordance with GB/T50123-1999 and the specimen was tested on a AG-X plus universal testing machine. As an important indication of vegetation germination and growth, the surface hardness was measured using a Yamanaka soil hardness tester. The wind tunnel test for wind erosion resistance evaluation was conducted in the Key Laboratory of Desert and Desertification in Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences. The spraying concentration of W-OHC was 3% and the wind with velocity of 10, 15, 20, 25 m/s lasted for 20, 15, 10, and 7 min, respectively. The property of freezing-thawing of the sand-fixing layer was evaluated. The freezing-thawing cycles was 50 times under -25℃ for 22 h and 25℃ for 2 h. Both the wind erosion resistance and freezing-thawing performances were assessed by compressive strength and surface hardness. Then the experiment of water retention was carried out in different spraying amounts and concentrations of W-OHC solution, and the rate of water content in sand-fixing layer was obtained. Finally, a field test in the flowing sand dunes around Qinghai Lake was carried out. The 2% and 3% W-OHC with spraying amount of 3 L/m2were compared. The results showed that： 1） W-OHC solution had good permeability on sand and a flexible sand fixation layer with porosity was formed when different concentrations of W-OHC solution were used. The penetration thickness decreased with the increase of W-OHC concentrations. When the conce

关 键 词：聚氨酯 力学性能 风洞 渗透性能 抗风蚀 固沙促生 

分 类 号：S156.49[农业科学—土壤学]