摘要
根据聚乙烯醇（PVA）∶水∶甲醛的不同配比制备出9种聚乙烯醇缩甲醛（PVFM）泡沫塑料管,通过考察其密度、吸水倍率、发泡点、渗水速率、孔隙结构等指标,综合分析其负压渗水性能。结果表明,当水比例为8.75时表观密度最小、吸水倍率最大;甲醛比例在0.50~1.00间的变化对两者无明显影响。9种不同配比的PVFM产品发泡点值在26.7~73.3kPa之间变化,且在水比例7.50或者甲醛比例0.75时会达到较高水平,比例过低或过高都会使发泡点下降。在-5kPa与-10kPa下,水比例≥7.50的PVFM产品,渗水速率相对较快。PVA∶水∶甲醛为1∶7.50∶0.75的5号PVFM产品的平均孔径小,泡孔较均匀,发泡点值为65.3kPa,饱和导水率可达7.45×10-4 cm/s,理论上可以作为高性能负压渗水材料在负压灌溉中使用。
In order to explore new negative pressure seepage materials,a series of polyvinyl formal（PVFM）with 9mixture ratios of polyvinyl alcohol（PVA）：H2O：formaldehyde were chemical combined,and their density,water absorption,bubble point,water exudation rate,pore structure were tested,the appropriate mixture ratio was discussed and screened.The results show that,the apparent density reaches the minimum and water absorbency reaches the maximum when H2 O ratio is 8.75,while both of the apparent density and water absorbency are not evidently changed within the range of formaldehyde ratio of 0.50~1.00.Bubble point is largely different between,the maximum of 73.3kPa when the ratio is 1∶7.50∶0.50 and the minimum of 26.7kPa when the ratio is 1∶8.75∶0.50.Generally,the bubble point could reach a high level at H2 O ratio of 7.50 or formaldehyde ratio of 0.75.Under-5kPa and-10 kPa,water exudation rate is higher when H2 O ratio is larger than 7.50.In theory,the PVFM with PVA∶H2O∶formaldehyde ratio of 1∶7.50∶0.75,of which the mean pore size is small,bubble point is 65.3kPa,saturated hydraulic conductivity is 7.45×10-4 cm/s,could be used as a novel negative pressure seepage material in negative pressure irrigation.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2015年第10期133-139,共7页
Polymer Materials Science & Engineering
基金
国家高技术研究发展计划(863计划)(2013AA102901)
关键词
聚乙烯醇缩甲醛
配比
负压渗水材料
发泡点
渗水性能
孔径
负压灌溉
polyvinyl formal
mixture ratio
negative pressure seepage material
bubble point
water exudation performance
pore size
negative pressure irrigation
