铸膜液结构对PVC/PMMA合金微滤膜性能的影响

通过高分子合金化,以L-S相转化法制备了PVC/PMMA非对称型合金微滤膜,考察了铸膜液结构对微滤膜结构与性能的影响.结果表明:随聚合物浓度、铸膜液温度升高合金膜水通量降低,平均孔径减小;增大PMMA含量,水通量上升,平均孔径增大;随添加剂量的增加,合金膜水通量上升,平均孔径减小.     

不同聚合物浓度对聚醚砜微滤膜性能的影响

研究了不同聚合物浓度对浸没沉淀相转化法制备聚醚砜(PES)微滤膜的形态结构、成膜厚度、孔隙率、过滤性能、亲水性的影响。实验结果表明:随聚合物浓度的增加,铸膜液黏度增大,导致铸膜液分相固化时间较短,表面孔隙率逐渐减少,且成膜孔隙率、纯水通量及膜亲水性均在聚合物浓度为14%时呈现最佳值。     

聚偏氟乙烯／蒙皂石超滤膜的制备及性能研究

以聚偏氟乙烯(PVDF)为原料,无机层状材料蒙皂石(MMT)为添加剂,通过溶胶-凝胶相转化法研制成PVDF/MMT超滤膜.考察了MMT质量分数在0%~9%范围内对铸膜液黏度、膜孔隙率、孔径、水通量、PEG20000截留率等性能的影响,以及相图和DSC曲线的变化.实验结果表明,MMT的加入使铸膜液的黏度增加,铸膜液呈现非牛顿流体中的假塑性流体的特性;当MMT加入质量分数为7%时,PVDF/MMT超滤膜水通量可达94.32 L·m-2·h-1,对PEG20000的截留率达95.2%.MMT的添加对成膜过程也有影响,从相图分析,加入MMT改变了液–固双节点的位置,铸膜液对非溶剂的容纳能力降低;而从DSC测试曲线得知PVDF/MMT膜的结晶度低于PVDF膜.     

铸膜条件对相转化法制备PVDF微滤膜性能的影响

研究了浸没沉淀相转化法制备聚偏氟乙烯(PVDF)微滤膜过程中挥发时间、凝胶浴温度、铸膜厚度和铸膜速度对成膜的形态结构、孔隙率、过滤性能以及污染性能的影响。结果表明,随挥发时间延长,成膜孔隙率变小,纯水通量先增加后减小,以10 s为挥发时间制得的膜抗污染性能最强;随凝胶浴温度的升高,孔隙率、纯水通量及抗污染性能先增大后减小,在45℃成膜污染速率最低;随铸膜厚度的增加,纯水通量逐渐减小,孔隙率呈现先增加后减小的规律,且铸膜厚度为0.25 mm时成膜抗污染性能最好。     

蚕蛹蛋白分离膜的探索研究

本研究以聚乙烯醇（PVA）为膜材料，以聚乙二醇（PEG）为致孔剂配制铸膜液，凝固浴为去离子水，利用相转化法制备超滤（UF）膜用于分离蚕蛹蛋白。实验中初步研究了不同分子量的PEG对成膜的影响：不同比例的PVA／PEG-1000条件下．不同PVA成型浓度所成膜对蚕蛹蛋白的截留情况。结果显示PEG-1000对PVA—PEG超滤膜的改性有较好的作用。得到无色透明、机械强度较高的膜。当PVA／PEG-1000≤9时。得到的是半透明膜，而在PVA／PEG-1000≥9时，得到的膜透明度高；当PVA浓度不同时成型，即使膜的成分相同，膜的性能也有很大的不同。在PVA的浓度为5％时，膜的截留率在PVA／PEG-1000=12时最好。达83．47％。在PVA的浓度为10％时，膜的截留率在PVA／PEG-1000=3时最好，达83．76％；在PVA的浓度为15％时，其截留率比较高，虽都没有超过80％。但比较稳定。     

PVC-溶剂-非溶剂相混合参数表征

<正>聚合物-溶剂-非溶剂(沉淀剂)三元相混合参数是影响浸没沉淀相转化法成膜的一个关键因素,溶剂/非溶剂的选择影响成膜机理:瞬时液-液分相和延时液-液分相。顺时液-液分相是指铸膜液浸入凝胶浴后迅速分相,有利于形成大孔结构;延时液-液分相是指铸膜液浸入凝胶浴后一定时间后才开始分相成膜倾向于形成海绵状结构[1]。这是由于当在铸     

Mg（ClO4）2填充聚丙烯晴微滤膜的制备及性能研究

以高氯酸镁(Mg(ClO4)2)为添加剂,采用浸没沉淀相转化法制备了聚丙烯晴(PAN)微滤平板膜。考察了Mg(ClO4)2含量对PAN微滤平板膜纯水通量、膜污染速率、孔隙率、接触角和膜表面形态的影响;并根据相关结论探讨了PAN微滤平板膜抗膜污染主要物质SMP的特性试验。结果表明,PAN微滤平板膜中添加Mg(ClO4)2可改变成膜性能,当Mg(ClO4)2的质量分数为1.5%时,PAN微滤平板膜的成膜性能最优,抵抗强疏水性有机物组分污染的能力增强。     

聚合物孔隙率的研究

膜的应用在当今引起了广泛的关注。本文用L-S相转化法制备了PAN/PVC、PAN/PVA体系的非对称性膜和用PVP做成孔剂的PVC膜。以L-S相转化法成膜可以制得非对称型结构膜，这种膜结构具有极薄而致密的表层，有助于同时提高膜的选择性、渗透性及抗污染性。同时，探讨了孔隙率对膜结构和膜性能的影响。实验结果表明，用高分子来做膜材料，可以利用高分子的相容性的变化来控制膜的孔隙率，而调控制膜的势力学因素和动力学因素可以改变高分子的相容性，从而影响膜的结构和性能。实验结果证实了可以制备出PAN/PVC膜，PAN/PVA膜和用PVP做成孔剂的PVC膜。这里我们主要研究了这些膜的孔隙率。     

PVA/EC合金膜材料的制备及其界面性能表征

采用溶液共混和液-固相转变法制备出聚乙烯醇/乙基纤维素(PVA/EC)合金和EC均质膜材料作为高效液相色谱柱填料. 采用 HPLC法探讨了合金化前后PVA膜材料的界面性能及亲水性变化,并以粘度法、折光指数法、红外光谱法及热重分析法研究了EC与PVA的相容性和热稳定性. 实验结果表明,两者之间具有很好的相容性;PVA/EC合金对不离解的极性有机物的分离性能优于EC均质膜材料.     

制取聚苯胺-聚乙烯醇导电共混膜的条件研究

用共混浇铸法制备PAN-PVA共混膜,探讨了制膜液中PAN与PVA的质量比、成膜干燥温度和制膜液浓度对共混膜性能的影响,测定了膜的拉伸断裂强度和断裂伸长率。结果表明,制取电导率高、力学性能较好的适合作电磁屏蔽材料的PAN-PVA共混膜的条件为:制膜液内PVA的质量百分数为40%,成膜干燥温度为80℃,制膜液浓度为17.0 mg/mL。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料，介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比，介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序，对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

Inorganic/organic nanocomposite coatings: The next step in coating performance

Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Some Large Wood-Boring Beetles in Southeastern USA

Ethanol and α-pinene were tested as attractants for large wood-boring pine beetles in Alabama, Florida, Georgia, North Carolina, and South Carolina in 2002–2004. Multiple-funnel traps baited with (−)-α-pinene (released at about 2 g/d at 25–28°C) were attractive to the following Cerambycidae: Acanthocinus nodosus, A. obsoletus, Arhopalus rusticus nubilus, Asemum striatum, Monochamus titillator, Prionus pocularis, Xylotrechus integer, and X. sagittatus sagittatus. Buprestis lineata (Buprestidae), Alaus myops (Elateridae), and Hylobius pales and Pachylobius picivorus (Curculionidae) were also attracted to traps baited with (−)-α-pinene. In many locations, ethanol synergized attraction of the cerambycids Acanthocinus nodosus, A. obsoletus, Arhopalus r. nubilus, Monochamus titillator, and Xylotrechus s. sagittatus (but not Asemum striatum, Prionus pocularis, or Xylotrechus integer) to traps baited with (−)-α-pinene. Similarly, attraction of Alaus myops, Hylobius pales, and Pachylobius picivorus (but not Buprestis lineata) to traps baited with (−)-α-pinene was synergized by ethanol. These results provide support for the use of traps baited with ethanol and (−)-α-pinene to detect and monitor common large wood-boring beetles from the southeastern region of the USA at ports-of-entry in other countries, as well as forested areas in the USA.