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用于乙醇-水分离的SA-PVA/PSF中空纤维渗透汽化复合膜 总被引：1，自引：1，他引：0
Using polysulfone (PSF) hollow fiber ultrafiltration membranes as the substrate, sodium alginate (SA) and polyvinyl alcohol (PVA) blend solutions as the coating solution, and maleic anhydride (MAC) as the cross-linked agent, SAPVA/PSF hollow fiber composite membranes were prepared for the dehydration of ethanol-water. The effects of different sodium alginate concentration in the coating solutions and different operating temperatures on pervaporation performance were investigated. The experimental results showed that pervaporation performance of the SA-PVA/PSF composite membranes for ethanol-water solution exhibited a high separation factor although they had a relatively low permeation flux. As SA concentration in SA-PVA coating solution was 66.7% and the operating temperature was 40 ℃, SA-PVA/PSF hollow fiber composite membrane (PS4) had a separation factor of 886 and flux of 12.6 g/(m2·h). Besides, SA-PVA/PSF hollow fiber composite membranes (PS3 and PS4) were used for the investigation of the effect of ethanol concentration in the feed solution on pervaporation performance. 相似文献
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聚乙烯醇的分子量及醇解度对其生物降解性的影响 总被引：5，自引：0，他引：5
从四川维尼纶厂生产车间下水道和污泥中分离出了可降解聚乙烯醇（PVA）的微生物Bacillus sp. 和Curtobacterium sp.，并建立了相应的PVA生物降解环境。采用吸光度分析方法考察了分子量及醇解度对PVA生物降解性的影响。结果表明：分离的微生物和以此为基础建立的生物降解环境可用于PVA生物降解性研究；在较短时间内，就可使PVA发生较高程度的降解；在所建立的降解环境中，PVA的分子量和醇解度对其降解性有一定的影响。降解前后FT-IR及1H NMR分析表明，在降解过程中PVA分子链发生了断裂。 相似文献
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The main thrust of this research was to determine the effectiveness of polyvinyl alcohol (PVA) powder in enhancing the durability of short GFRC materials. Accelerated aging of the materials was achieved through low-pressure steam curing in a moist chamber. The strength and ductility of GFRC were measured by the direct tension test, which showed that incorporation of PVA powder into GFRC could improve its mechanical behaviour and turn it from brittle to ductile. To investigate the mechanism of the tensile strength enhancement, the fiber-matrix interface was examined by polarizing optical microscopy and scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDAX). It was found that PVA powder tended to migrate to the fiber-matrix interfacial zone and thus prevented the accumulation of calcium hydroxide in this area. PVA film around the fiber resulted in a more ductile interfacial microstructure and better bonding between fiber and matrix, which should be responsible for enhancing the tensile property and preventing the aging of GFRC. Furthermore, PVA powder reduced the microhardness and brittleness at the interface. 相似文献
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采用静电纺丝法制备聚乙烯醇（PVA）超细纤维膜,利用扫描电子显微镜（SEM）观察溶液浓度、纺丝电压、纺丝距离对纤维微观形貌的影响,并采用正交设计对纺丝工艺参数进行优化。实验结果表明:纺丝电压是影响纤维平均直径的最重要的参数。经过优化,纺制出最小直径为0.27μm的PVA超细纤维。 相似文献
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The intrinsic viscosity and viscometric interaction parameters of perfluorosulfonic acid(PFSA) and poly(vinyl alcohol)(PVA) were measured by dilute solution viscometry.The miscibility between PFSA and PVA was estimated by the criteria of △B and μ.The results indicated that PFSA and PVA were completely miscible for any weight fraction in aqueous solution. 相似文献
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用拉伸PVA膜法研究了属于D_(2h)、D_(3h)点群纳米级分子的取向行为,并用Tanizaki Y的解析理论给出了取向分布函数和取向角,指出可以利用取向角讨论单个纳米粒子的形状。 相似文献
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三聚氰胺改性脲醛树脂胶粘剂的性能研究 总被引：4，自引：0，他引：4
探讨了反应温度、pH值、甲醛尿素摩尔比、PVA的用量、三聚氰胺的用量等对脲醛树脂胶液的粘度、稳定性、耐水性、胶合质量的影响．结果表明：控制反应温度80℃,PVA用量为尿素与甲醛溶液总质量的1%,pH值为5.0,甲醛与尿素摩尔比为1.6,三聚氰胺用量为10%时合成的胶粘荆游离甲醛含量为0.052%,耐沸水时间为163min,胶粘剂稳定性好． 相似文献
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发泡聚乙烯醇是一种环保型的泡沫塑料,广泛应用于在清洁材料、过滤材料、医用材料等领域,但尚未见在包装领域应用的报道.本文详细讨论了发泡聚乙烯醇的3种发泡方法(机械发泡法、化学发泡法、成孔剂发泡法)、制备技术以及性能(耐热性、耐化学药品性、力学性能、吸液性能等)方面的研究进展,并对其在液态产品缓冲吸液包装上的应用可行性进行了分析,提出进一步研究的主要思路. 相似文献
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The raw canvas paintings of Morris Louis and similar color field works, with their extreme vulnerability to staining and structural damage, present a challenge for safe and successful treatment design, often testing the bounds of our abilities as conservators and stimulating expansion of treatment methodologies. The ability to draw from specialized textile and painting conservation techniques, and to understand their long-term implications and impact on aesthetic perception, is essential for the conservator of these modern paintings. A large Morris Louis, Untitled (Floral), held as a non-accessioned work at the Museum of Fine Arts, Houston, provided an ideal example to explore the intersection of minimally interventive treatments with the need for aesthetic perfection. 相似文献