快速固化酚醛树脂胶黏剂的贮存期稳定性研究

对制备的快速固化酚醛树脂胶黏剂的贮存稳定性进行了较为全面的研究,考察期为6个月。在6个月的贮存期过程中,就酚醛树脂胶黏剂的黏度、凝胶时间及力学性能分别进行了测试,研究了其变化规律。同时为了深入研究贮存期对酚醛树脂胶黏剂的固化行为和官能团的影响,又利用了DSC和IR对不同贮存期的酚醛树脂胶黏剂进行表征。研究结果表明,该快速固化酚醛树脂胶黏剂在6个月内具有较好的贮存期稳定性。     

高邻位线性钼酸改性酚醛树脂胶黏剂的研制

以苯酚、甲醛为原料,钼酸为改性催化剂,制备了高邻位钼酸改性酚醛树脂胶黏剂,分析了催化剂种类、酚醛比、合成时间以及钼酸改性剂对酚醛树脂胶黏剂的影响,并考察了高邻位钼酸改性酚醛树脂胶黏剂的粘接性能和耐热性能。结果表明,以氧化锌为催化剂,钼酸为改性催化剂,当酚醛比为1.7、合成时间为6h时,制备的高邻位酚醛树脂胶黏剂的性能较好。     

固化剂对酚醛树脂灌封胶性能的影响

为满足灌封胶黏剂中温固化耐高温的要求,研制新型耐高温灌封胶黏剂体系是十分重要的。研究了酚醛树脂固化剂对酚醛树脂挥发份、粘接强度、玻璃化转温度、固化温度等的影响,确定了固化剂和酚醛树脂最佳固化比例。表明采用的酚醛树脂固化剂可以显著降低酚醛树脂的挥发份,降低酚醛树脂固化温度,提高常温粘接强度,缺点是使酚醛树脂的玻璃化转变温度和高温剪切强度稍有下降,显示了固化剂的优异性能。该胶黏剂作为中温固化耐高温灌封胶黏剂可以满足航空工业耐高温的技术要求。     

改性邻苯二甲腈酚醛树脂胶黏剂的研究

采用4-硝基邻苯二甲腈和线型酚醛树脂反应,制备出邻苯二甲腈酚醛树脂。采用改性树脂和增韧剂对邻苯二甲腈酚醛树脂进行改性,制备出改性邻苯二甲腈酚醛树脂胶黏剂。并借助IR、DSC、TG对合成树脂及胶黏剂进行表征。该胶黏剂可在200℃温度下固化,固化产物具有较高的耐热性能和粘接性能。     

微波辐射法合成葡萄糖苯酚树脂胶黏剂

以葡萄糖代替甲醛合成一种新的环保型酚醛树脂胶黏剂。在碱性条件下以微波加热法合成葡萄糖苯酚树脂胶黏剂、通过正交实验获得最佳反应条件,同时以此方法对树脂的固化条件进行了研究。微波加热条件下合成葡萄糖苯酚树脂胶黏剂的最佳条件是：葡萄糖：苯酚=7：1;pH：12;催化剂用量：1．4％;反应时间：6min。实验证明,微波辐射波法可以成功合成葡萄糖苯酚树脂胶黏剂,且该胶黏剂是一种环保型胶黏剂。     

快速固化酚醛树脂胶黏剂的研制

以缩短酚醛树脂固化时间为目的,使用纳米氧化铝为催化剂,丁腈橡胶为增韧剂,AlCl3络合物为固化促进剂,制备了一种能够快速固化的酚醛树脂胶黏剂。通过固化时间、DSC、TG和力学性能等测试,结果表明,当加入15%丁腈橡胶和2%AlCl3络合物时,酚醛树脂胶黏剂的增韧效果和固化速度均为最佳,可在180℃下20min内实现快速固化,同时具有优异的耐热性能和力学性能。     

配方精选

正酚醛改性环氧胶黏剂环氧树脂100酚醛树脂45聚砜树脂粉10六亚甲基四胺1乙二胺5其他助剂适量性能及用途:该胶是一种耐高温的胶黏剂,适用于金属、玻璃、陶瓷和塑料等材料的粘接。室温固化耐高温环氧胶黏剂     

ZUV系列紫外光固化胶黏剂的制备与应用

紫外光固化胶黏剂是近年来发展较快的一种胶黏剂,它是利用紫外光引发具有化学活性的液态材料快速聚合交联,数秒内固化成膜,是一种高性能、高效率的胶黏剂。通过合成预聚物,用活性稀释剂进行改性,并配合加入各种光引发剂的方法,制备了ZUV系列紫外光固化胶黏剂。该系列紫外光固化胶黏剂具有固化速度快、粘接强度高、抗震性好等优点。按照定位时间的快慢我们将其分为ZUV-X,ZUV-3188,ZUV-5188等三个品种,它们已广泛应用于金属、玻璃、水晶、石材等多种材料的粘接,具有较好的社会经济效益。     

木质素基酚醛树脂胶黏剂研究进展

在经过处理改性后,木质素可部分替代苯酚,用于生物基酚醛树脂胶黏剂的制备,降低胶黏剂生产成本,同时能够实现生物质的高效利用,促进循环经济.综述了目前木质素活化改性制备酚醛树脂胶黏剂的最新研究进展,重点介绍了化学改性、物理改性及生物改性等提高木质素反应活性的主要改性方法,对比了不同改性方法合成的木质素基酚醛树脂胶黏剂性能.     

碳基复合材料用耐高温胶黏剂的研制

采用耐热酚醛树脂杂化了磷酸盐胶黏剂,以纳米氧化铝、氧化锆和氧化锌为固化剂,制备了一种对C/C和C/SiC复合材料具有良好粘接性能的胶黏剂。通过不同测试温度下的剪切强度,差示扫描量热仪（DSC）,热失重（TG）以及扫描电子显微镜（SEM）探究了杂化胶黏剂的力学性能、固化行为、耐热性能以及高温下胶黏剂结构的变化。结果表明：酚醛树脂的加入,保持了耐热性能,降低了体系固化的固化温度,有效地提高了磷酸盐胶黏剂对C/C、C/SiC两种复合材料力学性能,室温下剪切强度均高于10MPa。     

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.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

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.     

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.     

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。