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首页> 外文学位 >VAPOR TRANSPORT IN POLYMERIC MEMBRANES - DESIGN AND DEVELOPMENT OF A SEMIPERMEABLE BARRIER FABRIC.
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VAPOR TRANSPORT IN POLYMERIC MEMBRANES - DESIGN AND DEVELOPMENT OF A SEMIPERMEABLE BARRIER FABRIC.

机译：聚合物膜中的蒸气运输-半渗透性屏障织物的设计和开发。

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摘要

The diffusion of selected organophosphorous vapors, carbon tetrachloride vapor and oxygen through polymeric membranes and composite fabrics was studied. The organophosphorous compounds employed were dimethyl methyl phosphonate and 2,2-dichlorovinyl methyl phosphate. Polyethylene teraphthalate (PET), polyvinyl chloride (PVC), cellulose acetate and polytetrafluoroethylene (PTFE) membranes were used. Composite fabrics included an active carbon impregnated polyurethane foam fabric, bi-membrane composites of PET and PVC and bi-membranes with an encapsulated active carbon layer. Diffusion parameters were evaluated by breakthrough time, diffusion rate and diffusion coefficients. Diffusion properties were measured using flame ionization and thermal conductivity detectors with a gas chromatograph.; Oxygen diffusion rates and coefficients did not vary significantly among the membranes and composites tested. Breakthrough times for the organophosphorous and carbon tetrachloride vapors varied greatly. Additions of a second membrane and a carbon layer for the membrane composites were observed to at least double the measured breakthrough times. Diffusion rates were affected more by vapor pressure than by the construction of the barrier. Diffusion coefficients were significantly reduced by composite construction. Membrane bilayer composites reduced the calculated diffusion coefficients by as much as an order of magnitude.; Vapor absorption by single membranes and the polyurethane foam fabric was measured using a static gravimetric technique and was evaluated in terms of a change in weight with time. It was determined that PET membranes had the greatest sorption capacity per unit volume ranging from 0.576 to 17.77 mg/cm('2)/cm('3). The low values obtained for the polyurethane foam, in the range of 0.068 to 1.513 mg/cm('2)/cm('3), were attributed to water poisoning of the active carbon which provided the absorption system for the fabric.; Membrane stability to vapor exposure was evaluated by effect on tensile properties, surface degradation and decrease in percent crystallinity. Thermal analysis indicated significant, greater than 70 percent, reduction in crystallinity for PET after vapor exposure. Scanning electron micrographs did not show any detectable surface effects.
机译：研究了选定的有机磷蒸气，四氯化碳蒸气和氧气在聚合物膜和复合织物中的扩散。所使用的有机磷化合物是膦酸二甲酯甲酯和磷酸2，2-二氯乙烯基甲酯。使用了聚对苯二甲酸乙二酯（PET），聚氯乙烯（PVC），醋酸纤维素和聚四氟乙烯（PTFE）膜。复合织物包括活性炭浸渍的聚氨酯泡沫织物，PET和PVC的双膜复合材料以及具有包封活性碳层的双膜。通过穿透时间，扩散速率和扩散系数评估扩散参数。扩散特性是使用火焰离子化和热导检测器以及气相色谱仪测量的。在测试的膜和复合材料中，氧气的扩散速率和系数没有显着变化。有机磷和四氯化碳蒸气的穿透时间变化很大。观察到第二膜和用于膜复合物的碳层的添加至少使测得的穿透时间增加了一倍。蒸汽压力对扩散速率的影响比屏障的构造要大。复合结构大大降低了扩散系数。膜双层复合材料将计算得出的扩散系数降低了一个数量级。使用静态重量技术测量单层膜和聚氨酯泡沫织物的蒸气吸收，并根据重量随时间的变化进行评估。可以确定，PET膜的单位体积最大吸附容量为0.576至17.77 mg / cm（'2）/ cm（'3）。聚氨酯泡沫的低值在0.068至1.513 mg / cm（'2）/ cm（'3）范围内，这归因于活性炭的水中毒，为织物提供了吸收系统。通过对拉伸性能，表面降解和结晶百分率降低的影响来评估膜对蒸气暴露的稳定性。热分析表明，蒸气暴露后，PET的结晶度明显降低了70％以上。扫描电子显微照片未显示任何可检测的表面效应。

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  • 作者

    KIMMITT, DEBORAH ALYCE.;

  • 作者单位

    Clemson University.;

  • 授予单位 Clemson University.;
  • 学科 Textile Technology.
  • 学位 Ph.D.
  • 年度 1982
  • 页码 119 p.
  • 总页数 119
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 轻工业、手工业;
  • 关键词

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