松香基丙烯酸酯核-壳共聚压敏胶的研制

根据“分子设计”的原理,采用种子乳液聚合的方法研制出一种具有复合核／壳结构的改性松香型丙烯酸酯压敏胶聚合物乳液,讨论了核壳乳液比例、引发剂、乳化剂、相比等因素对乳液性能的影响,确定了最佳的松香酯乳液用量。结果表明,所得产物是一种性能优良的压敏胶粘剂。     

绷带用聚丙烯酸酯乳液型压敏胶的研制

合成了一种绷带用聚丙烯酸酯乳液型压敏胶,测试了乳液的粘度、压敏胶的T型剥离强度、初粘力及持粘力。结果表明:当反应温度为81～85℃、引发剂用量为0．35%～0．45%、复配乳化剂用量为3．8%时,制得的聚丙烯酸酯乳液性能较好;加入一定量的松香乳液,可有效地提高压敏胶的性能。     

压敏胶用含氢化松香酯核/壳型丙烯酸酯乳液的制备

采用细乳液两步法制备PSA(压敏胶)用松香衍生物包覆的核/壳型丙烯酸酯乳液。着重探讨了细乳液的聚合条件、氢化松香二甘醇酯(HR-DGE)掺量等对乳液及其PSA性能的影响。研究结果表明:PSA用乳液的最佳聚合条件是w(HR-DGE)=5%、w(APS)=0.8%(均相对于单体总质量而言)、保温时间为2~3 h和保温温度为85℃,此时单体转化率相对最高(95%);当w(HR-DGE)=4%时,PSA的初粘力和持粘力俱佳;随着HR-DGE掺量的增加,PSA用乳液对BOPP薄膜的润湿性增大、相对分子质量(Mr)下降、Mr分布变窄和玻璃化转变温度(Tg)呈先降后升态势,并且PSA的初粘力略有升高、持粘力明显下降。     

丙烯酸酯乳液型压敏胶的研究进展

综述了聚丙烯酸酯乳液型压敏胶的性能特点以及各种改性方式的研究进展。通过加入增粘树脂、有机硅单体、反应性乳化剂或采用核壳聚合的方式提高其粘接强度,改善耐水性差耐高温性差及涂布干燥等缺点,使聚丙烯酸酯的用途更加广泛。     

有机硅改性丙烯酸酯核—壳结构压敏胶聚合物乳液

华南理工大学的张心亚等人以丙烯酸丁酯、醋酸乙烯酯、 2 -甲基丙烯酸羟乙酯、丙烯酸、有机硅氧烷为原料 ,采用种子乳液聚合法制得标题物。有机硅单体的引入 ,提高了聚合物乳液的持粘力、 1 80°剥离强度和贮存稳定性 ;有机硅单体合适的用量为 1 %。有机硅改性丙烯酸酯核-壳结构压敏胶聚合物乳液     

松香基丙烯酸酯乳液压敏胶的制备

由松香和富马酸合成富马海松酸,然后由富马海松酸与丙烯酸-2-羟乙酯合成富马海松酸双(2-丙烯酰氧乙酯)(AEFE)。通过酸值、FTIR和~1HNMR等表征发现,AEFE分子结构上具有两个环外C=C和1个羧基。以AEFE为反应型增粘树脂,采用原位共聚法改性丙烯酸酯乳液,考察了AEFE和壬基酚聚氧乙烯醚硫酸钠(NPES)的用量对乳液聚合反应及压敏胶性能的影响。结果表明:随着AEFE用量增加,单体转化率未显著降低,且经过共聚反应后AEFE的C=C消失,说明AEFE具有很强的反应活性。当AEFE和NPES的用量分别为单体总质量的8.4%和0.64%时,增粘树脂与聚丙烯酸酯相容性良好,所得改性丙烯酸酯乳液压敏胶粘接性能最佳,此时初粘力为18#钢球、180°剥离强度为7.21 N/25 mm,且持粘力大于100 h。     

丙烯酸酯乳液医用压敏胶的研究进展

综述了乳液型丙烯酸酯类医用压敏胶的性能特点以及各种改性方式的研究进展。通过加入增粘树脂、有机硅改性，采用反应性乳化剂、核／壳乳液聚合或接枝改性等方法提高其粘接强度，改善耐水性、耐温性及涂布性能，并对其应用前景进行了展望.     

有机硅改性丙烯酸酯核-壳结构压敏胶聚合物乳液的研制

采用种子乳液聚合的方法制备了一种新型具有核/壳结构的有机硅改性丙烯酸酯压敏胶聚合物乳液,讨论了多官能团有机硅氧烷功能性单体、核壳单体结构、乳化剂、引发剂以及聚合温度等因素对压敏胶聚合物乳液性能的影响。     

标签用松香基丙烯酸酯乳液压敏胶的研制

利用歧化松香对丙烯酸异辛酯、醋酸乙烯酯等单体的共聚乳液体系进行改性,制备核壳共聚乳液。首先考察了乳化剂的用量及其配比、单体的加料速度等对预乳液的影响,同时还考察了引发剂以及歧化松香对聚合物乳液性能的影响。结果表明:复合乳化剂(SDS／OP-10)的用量3％-4％;SDS／OP-10的质量比为1:3;引发剂的用量0．4％;歧化松香用量为6％时,获得了综合性能优良的标签用压敏胶,尤其是初粘性得到显著提高。     

玻纤网格布用高性能丙烯酸乳液压敏胶的研制

介绍了引入反应型乳化剂采用种子乳液聚合法研发成功的用于玻纤网格布的改性丙烯酸乳液压敏胶：通过测试初粘性、持粘性、90。剥离强度、吸水率等性能表征了该产品的性能;探讨了玻璃化转变温度、反应性乳化剂和改性松香酯乳液等因素对聚合物乳液性能的影响。     

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.     

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.     

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。     

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.     

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.     

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.