积层电路板用UV感光预聚物的合成

通过在酚醛环氧树脂中引入烯丙基,以实现树脂的感光性,考察了四种催化剂和其不同用量及两种阻聚剂对反应的影响,利用配比不同的丙烯酸和酚醛环氧树脂合成出的感光预聚物,研究了其对感光组合物性能的影响.结果表明：催化剂的催化活性依次为十六烷基三甲基溴化铵＞三乙胺＞N,N-二甲基苯胺＞三乙醇胺;以十六烷基三甲基溴化铵为催化剂时其合适用量为1.5%;阻聚剂以对苯二酚为佳;当丙烯酸与酚醛环氧树脂的环氧基当量比为0.8时,以其改性产物配制的感光组合物的固化膜的附着力为一级,硬度为6H,具有良好的耐酸、耐碱和耐溶剂性.     

环氧丙烯酸酯预聚物的合成研究进展

综述了环氧丙烯酸酯预聚物的合成与改性。介绍了合成原理,环氧树脂、催化剂、阻聚剂对合成的影响;分别用醇、酸（酸酐）、半酯及聚氨酯4类物质对环氧丙烯酸酯改性,从而得到不同性能的环氧丙烯酸酯预聚物。     

马来酸酐改性邻甲酚醛环氧丙烯酸酯的动力学及应用

研究了马来酸酐改性邻甲酚醛环氧丙烯酸酯的动力学,并确定了动力学方程,分析了液态感光成像油墨在应用中出现低显和过显问题的原因,并提出了解决办法。研究结果表明,马来酸酐改性邻甲酚醛环氧丙烯酸酯遵循一级动力学模型,其反应的表观活化能Ea=23.74 kJ/mol,指前因子A=1.383 9×103m in-1,反应速率可以由dαdt=1.383 9×104e-823.314 7.40T(1-α)来定量描述;曝光强度、显影速度和喷淋压力是影响低显和过显问题的三个主要因素。     

紫外固化粉末涂料的合成及固化研究

用E-12、E-20环氧树脂与丙烯酸反应,合成了可紫外光固化的环氧丙烯酸酯预聚物,并对产物进行固化研究。讨论了催化剂的种类、反应温度、反应时间等对合成产物的影响,光引发剂的种类、光照时间等对固化产物的影响。结果表明:环氧树脂与丙烯酸以甲苯为溶剂、四丁基溴化铵为催化剂,在110℃下反应180 min为较适宜的反应条件;环氧丙烯酸酯以TPO为引发剂,120 w/cm的紫外灯光照15 s为较宜适的固化条件。     

马来酸酐及亚硫酸氢钠改性环氧树脂的研究

本文首先用马来酸酐对环氧树脂进行改性,并进一步与亚硫酸氢钠反应制备带磺酸基团的水性环氧树脂。系统地研究了马来酸酐改性环氧树脂的反应温度、催化剂用量、原料浓度及混合溶剂比例对反应的影响。随着温度的升高,催化剂用量和原料浓度的增加,生成交联网状产物的副反应都会明显增强,体系易凝胶;溶剂甲苯与丙酮的混合比例较低时,反应体系酸值难于准确监测,并且生成交联网状产物的副反应增强不利于反应的顺利进行。在马来酸酐改性环氧树脂进一步与亚硫酸氢钠反应制备具有水分散性的环氧树脂过程中,用元素分析法测定产物结构中的硫元素含量,并分析了乳液的粒径分布,适宜条件下制备的水性环氧树脂分散体系平均粒径为110nm,粒径分布窄,具有良好的分散稳定性。     

碱显影耐高温感光树脂的研究

研究了稀碱显影耐高温感光树脂的合成及由树脂配置的PCB光致成孔用的光成像绝缘油墨(PDD)的性能。采用丙烯酸类单体改性F-51型酚醛环氧树脂的方法,合成具有光固化特性的酚醛环氧丙烯酸酯树脂,再用马来酸酐进行改性,在分子链上引入羧基,使树脂具有良好的碱溶性。实验表明,选用三乙胺为催化剂,阻聚剂含量为1．5％,反应温度为80℃,催化剂含量为2．0％,转化率较高。当改性树脂羧基含量在35％～40％时,PDD具有较好的碱溶性和耐热性。     

改性环氧丙烯酸酯胶粘剂预聚体增韧改性研究

采用聚乙二醇改性环氧E-44树脂,改性后E-44与α-甲基丙烯酸进行酯化反应,得到改性环氧丙烯酸酯预聚体。由单因素实验确定反应条件如下：第一步反应温度为90℃,第二步反应温度为95℃,聚乙二醇与环氧树脂的物质的量比为0．20：1,催化剂四丁基溴化铵用量为2．0％,阻聚剂对羟基苯甲醚用量为0．05％。红外光谱分析表明,改性环氧丙烯酸酯预聚体合成成功。由改性预聚体配制的胶粘剂粘度减小,拉伸剪切强度可达5．95MPa,180°剥离强度也有所提高。     

UV固化漆酚改性环氧丙烯酸酯喷印油墨的研制

为了解决天然生漆不能喷印和快干固化的问题,用生漆对环氧树脂进行改性,在此基础上合成了一种新型预聚物——漆酚环氧丙烯酸酯。以该预聚物作为主要成膜物质,制备了UV固化漆酚改性环氧丙烯酸酯喷印油墨。配制出色浆基墨后,采用正交实验法,以喷头通过性、黏度、固化时间为测试指标,优选出UV喷印油墨的最佳配方。最后通过粒径分析和性能评价验证了优选配方,制备的UV固化漆酚改性环氧丙烯酸酯喷印油墨综合性能优异。     

己二酸改性的环氧丙烯酸酯颜料润湿分散剂合成和应用

合成了己二酸改性环氧丙烯酸酯颜料润湿分散剂;分析了催化剂、合成温度、稀释条件等影响因素;综述了其在UV固化涂料和胶印油墨上的应用。     

水基光敏树脂的合成

以还氧树脂、丙烯酸、马来酸酐为原料 ,研究了原料投料比、反应温度、催化剂、溶剂等因素对合成水基光敏树脂性能的影响。当丙烯酸酸当量 /还氧当量 =1 0 0∶1 0 5,马来酸酐酸酐当量 /还氧当量 =1 0 0∶1 0 5,催化剂用四甲基氯化铵 ,酸改性溶剂为丙酮 ,反应温度为 80± 2℃ ,反应时间为 2 5h情况下 ,合成的水基光敏树脂水溶性较好 ,以其配制的水性涂料 ,含水在 1 0 %～ 2 0 % (质量分数 )时 ,涂料的涂布性能好 ,固化速度快 (2～ 3s)。     

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.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.