弱酸性条件合成脲醛树脂工艺的探讨

探讨了在弱酸性条件下合成低甲醛释放量的脲醛树脂工艺的可能性。同时,对不同pH值条件下合成脲醛树脂的工艺及其性能进行了研究,并采用傅立叶红外光谱和化学方法对脲醛树脂的官能团进行了分析,同时定性分析了不同pH值条件下合成树脂的热学性能。研究表明在弱酸性条件下合成脲醛树脂的树脂性能和其胶合板的力学性能达到国家标准并且其胶合板甲醛释放量达到GB／T17657—1999中的E,级标准。弱酸性条件下合成脲醛树脂的工艺不仅能降低生产成本,还能生产性能优异的脲醛树脂胶黏剂。     

TKO增粘树脂分子结构对胶料加工性能和增粘作用的影响

主要评述了ＴＫＯ系列橡胶增粘树脂的化学结构以及热塑性，相容性，极性，分子量，配合量等因素对其增粘作用的影响。     

凝胶渗透色谱法测定辛基酚醛增粘树脂相对分子质量及其分布

采用凝胶渗透色谱（GPC）法测定辛基酚醛增粘树脂相对分子质量及其分布,并研究辛基酚醛增粘树脂相对分子质量对其软化点和增粘效果的影响。确定的测试条件为：流速　1.0 mL·min^-1,柱温　40 ℃,试样溶液质量浓度　（2±0.2） mg·mL^-1;辛基酚醛增粘树脂的软化点和增粘效果随着其相对分子质量的增大而提高。     

液体洗涤剂的增粘

介绍了采用烷基醇酰胺、无机电解质、聚乙二醇酯、聚乙烯醇对液体洗涤剂的增粘作用，并对其增粘成本作了评价，为使用提供了参考。     

叔丁基酚醛增粘树脂对子午线轮胎硬胶料性能的影响

探讨了叔丁基酚醛增粘树脂对子午线轮胎硬胶料性能的影响，并与叔辛基酚醛增粘树脂、烃粘合树脂和石油树脂进行了比较。结果表明，叔丁基酚醛树脂能显著改善胶料的粘合性能及工艺性能，且对胶料的焦烧、正硫化时间无不良影响，但胶料的拉伸强度和定伸应力略有下降，其用量以４份为最佳。与其它增粘树脂相比，叔丁基酚醛增粘树脂增进胶料的粘合最有效．     

脲醛树脂的合成及其在堵水中的应用

本文以尿素和甲醛为主要原料来合成脲醛树脂,考察了甲醛和尿素的摩尔比、尿素加入方法、改性剂加量等对树脂中的游离甲醛含量以及树脂稳定性的影响,优化了合成条件。以氯化铵为固化剂,六次甲基四胺为固化速度调节剂对合成的脲醛树脂进行固化。通过性能评价,发现脲醛树脂的固化时间在较大范围内可以调节;固化后抗压强度高;在地层液体中具有低的溶解率;采用加入增孔剂的方法成功的使脲醛树脂具有了选择性。     

大有光PET切片的固相增粘

根据相同条件下不同 PET大有光切片固相增粘效果差异 ,对不同 PET大有光切片间内在质量进行分析表征 ,并探讨影响固相增粘的各种因素。通过同时升高结晶温度、延长结晶时间 ,升高后期增粘温度等方法 ,提高了切片固相增粘速度和切片特性粘数。     

MF新法制脲醛胶工艺研究成功

目前市场上使用的脲醛树脂胶因游离甲醛气味大，损害人体健康，固化后的制品耐久性差、脆性大、易开裂等弊端，越来越不适应应用及环保要求。为此四川省泸州市合江县化工研究所探索出一条生产脲醛树脂胶的新方法、新的生产技术路线和新的反应机理。整个过程无污染，易操作，符合环保要求，产品面市以来，深受广大用户欢迎。专家认为：该产品的工艺一改过去以六次甲基四胺、烧碱、甲酸、氯化铵等加入甲醛尿素在碱性和酸性条件下聚合反应的传统模式，而采用自行开发的ＭＦ助剂加入甲醛尿素中在８５℃条件下聚合反应，生成高粘耐水耐火的乳白粘…     

利用化学方法研究脲醛树脂的结构

脲醛树脂的结构随反应条件的变化会产生较大的变异。深入了解脲醛树脂的化学结构,对充分发挥其使用性能具有决定性意义。本文采用化学方法对四种工艺条件下合成的脲醛树脂进行相关分子含量测定,结合实验结果和合成工艺作了结构分析,并对比分析了衰减全反射红外光谱图。两种分析手段得出了一致的结论,说明化学方法完全可以用于脲醛树脂的结构表征。为相关的生产和应用人员掌握脲醛树脂的结构,提供了一种简单可行的方法。     

增粘树脂在橡胶压敏胶中的应用研究

介绍了6种不同增粘树脂的特性,研究了其对橡胶压敏胶初粘性、剥离力、持粘性的影响,以及性能随增粘树脂用量增加的变化趋势,测试了6种增粘树脂的耐老化性能。在6种增粘树脂中,石油树脂的耐老化性能和初粘性效果较好。     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

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.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009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、环氧树脂、不饱和聚酯树脂)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。     

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.     

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.