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1.
甲苯二异氰酸酯和硼砂交联改性聚乙烯醇胶水的研究   总被引:6,自引:0,他引:6  
探讨了硼砂和甲苯二异氰酸酯 ( TDI)对聚乙稀醇 ( PVA)胶水进行交联改性。采用正交实验法研究硼砂和 TDI的加入量对 PVA粘合剂的耐水性能和剥离强度的影响。利用硼砂、TDI与 PVA反应产物的水不溶性判断该交联反应的进程。研究结果表明 ,少量硼砂和 TDI能较大程度地提高 PVA胶水的耐水性能和粘结性能  相似文献   

2.
十二烷基硫酸钠对水基中TDI交联PVA反应的影响   总被引:2,自引:0,他引:2  
探讨典型的阴离子表面活性剂十二烷基硫酸钠(SDS)对甲苯二异氰酸酯(TDI)在水基中交联聚乙烯醇(PVA)反应的影响。利用该交联反应所形成的粘胶体系胶膜的水不溶性和压缩剪切强度检测结果来判断反应的交联程度。采用正交实验法,研究十二烷基硫酸钠的加入量、TDI的加入量、催化剂—D的加入量,以及交联反应的温度等因素对该交联反应程度的影响。  相似文献   

3.
对三异氰酸三苯基硫代磷酸酯交联聚乙烯醇乳胶   总被引:1,自引:1,他引:1  
采用正交实验法,研究在水基中,对三异氰酸三苯基硫代磷酸酯(TTPI)交联聚乙烯醇(PVA)的反应。利用其与PVA交联反应产物的不溶性和所形成的乳胶的压缩剪切强度检测结果来判断该反应的进程。结果表明,TTPI的加入较大幅度地提高PVA胶水的粘结性能和耐水性能。  相似文献   

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甲苯二异氰酸酯和硼砂交联聚乙烯醇环保乳胶的研究夏赤丹等.新型建筑材料,2002,(3):12采用甲苯二异氰酸酯(TDI)和硼砂共同交联改性聚乙烯醇(PVA),在表面活性剂的作用下形成乳胶。反应原理和交联反应后残存的游离TDI的检测结果说明,其对环境和人体健康都无明显影响。采用正交试验法,探讨了反应物质的组成对乳胶的黏结性能和胶膜的耐水性能的影响。研究结果表明,少量TDI和硼砂的加入能较大程度地提高该乳胶的黏结性能和胶膜的耐水性能,可用于内墙乳胶漆的生产、建筑装饰装修和木材加工的黏结,现已完成中试生产。海泡石用作建筑涂料增稠流…  相似文献   

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以甲苯二异氰酸酯(TDI)为交联剂,制备了TDI交联改性羧甲基纤维素(CMC)和聚乙烯醇(PVA)混合胶粘剂体系,并在交联反应完成后,用硼砂消乳增稠。采用正交试验法探讨了主要原材料配比、交联反应温度和交联反应时间等工艺条件对改性PVA胶粘剂性能的影响。研究结果表明:当PVA为12 g/100 m L、CMC为1.6 g/100 m L、TDI为4.00 m L/100 m L、硼砂为0.8 g/100 m L、交联反应温度为40℃和交联反应时间为90 min时,改性PVA胶粘剂具有良好的综合性能,其颜色稳定性及储存稳定性较佳,对木制品的粘接强度相对最好。  相似文献   

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TDI(甲苯二异氰酸酯)交联改性PVA(聚乙烯醇)能明显提高PVA胶粘剂的耐水性和粘接性能。以PVA掺量、羧甲基纤维素(CMC)掺量、交联剂TDI掺量、催化剂-X掺量、交联温度和交联时间为试验因素,压缩剪切强度为考核指标,采用正交试验法优选出合成该改性PVA胶粘剂的最佳工艺条件。研究结果表明:当PVA为12 g/100 m L、CMC为3.2 g/100 m L、φ(TDI)=3%、φ(催化剂-X)=0.4%(均相对于胶粘剂体积而言)、交联温度为30℃和交联时间为45 min时,所合成的单组分TDI改性PVA胶粘剂具有良好的环保性、粘接性,可广泛应用于林产工业、纸品工业以及建筑行业等领域。  相似文献   

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采用正交实验法探讨己二异氰酸酯(HDI)和泡花碱共同对聚乙烯醇(PVA)胶水进行交联改性。讨论其反应的原理、合成方法、粘结性能及其耐水性能。本研究结果获得一种耐水性能和粘结性能优良的聚乙烯醇类粘合剂。  相似文献   

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以TDI(甲苯二异氰酸酯)为交联剂、PVA(聚乙烯醇)为基体、HEC(羟乙基纤维素)为增黏剂和非离子型表面活性剂,制备了改性PVA白色乳胶。着重探讨了交联反应的原理和合成方法,并采用正交试验法优选出制备该乳胶的最佳工艺条件。研究结果表明:当PVA用量为10 g/100 m L、HEC用量为1.2 g/100 m L、TDI用量为4 m L/100 m L、反应温度为40℃和反应时间为45 min时,所得乳胶无毒、无害、无刺激性气体逸出,并且具有良好的粘接性能、冻融稳定性、储存稳定性和施工性能,可作为木材加工、纸品加工和建筑装饰用胶粘剂。  相似文献   

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以丁烷四羧酸(BTCA)为交联剂对胶原蛋白(Coll)/聚乙烯醇(PVA)复合体系进行化学交联处理;利用红外光谱分析了交联前后体系的化学变化;根据常见动力学机理函数,结合凝胶含量(α)研究复合体系的交联动力学。结果表明:BTCA对Coll/PVA体系有明显的交联作用,交联反应主要以酯化反应和酰胺化反应为主;BTCA/PVA和BTCA/Coll的表观凝胶反应活化能(E)分别为100.29,77.42 kJ/mol,表明BTCA较易与Coll反应;BTCA/Coll/PVA复合体系的最佳动力学函数G(α)为[-ln(1-α)]2/5,E为40.88 kJ/mol,比Coll/PVA复合体系的E(86.99 kJ/mol)明显减小,说明BTCA的加入降低了体系的E,有利于促进交联反应,可提高蛋白存留率。  相似文献   

10.
戊二醛交联碱木质素/聚乙烯醇膜的制备及其光学性能   总被引:3,自引:0,他引:3  
以碱木质素和聚乙烯醇(PVA)为原料,以戊二醛为交联剂利用流延法制备了碱木质素/PVA交联反应膜。通过单因素实验考查了碱木质素加入量、戊二醛加入量对木质素/PVA反应膜光学性能的影响。采用SEM和FT-IR方法分析反应膜的表面形貌和化学结构,紫外可见光谱法分析了交联膜的光学性能。结果表明:当碱木质素和聚乙烯醇质量比为1∶10,戊二醛加入量 1.67 %,薄膜的透光率和吸光度都较好。碱木质素/PVA薄膜结构中有醚键生成,碱木质素和PVA发生了交联反应;碱木质素/PVA反应薄膜表面较光滑;加入碱木质素后,薄膜在紫外光区的吸光度提高了近 90 %,在可见光区的透过率降低了近 40 %,碱木质素对薄膜的吸光度和透过率影响较大;戊二醛的加入量增多可见光区透过率有所增大,但戊二醛对薄膜在紫外区吸光度变化不大,薄膜的紫外线吸收主要是受碱木质素的影响。碱木质素/PVA反应膜可作为良好的紫外吸收材料。  相似文献   

11.
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.  相似文献   

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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.  相似文献   

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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。  相似文献   

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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.  相似文献   

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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.  相似文献   

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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.  相似文献   

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