气固相法生产氯化聚氯乙烯树脂的研究进展

着重介绍了气固相法制备氯化聚氯乙烯（CPVC）树脂的研究进展,对该法制备CPVC的生产工艺、反应机理以及反应动力学进行了阐述,其中生产工艺主要包括热引发氯化、光引发氯化和等离子体引发氯化等。     

气固相法氯化聚氯乙烯的研究进展

介绍了氯化聚氯乙烯(CPVC)的生产工艺和国内外的生产现状,重点阐述了气固相法合成氯化聚氯乙烯的热引发氯化、光引发氯化和等离子体引发氯化工艺的研究。     

气固相法合成氯化聚氯乙烯树脂的工艺

为了提升氯化聚氯乙烯树脂的合成质量,深化气固相法应用,对气固相法合成氯化聚氯乙烯树脂的工艺进行了研究。首先,对CPVC的性质以及制备方法进行了研究,指出了CPVC具有溶剂法、悬浮法、气固相法三种制备方法。然后,结合国内外研究现状,详细阐述了热、光、等离子体引发氯的气固相法合成CPVC工艺的研究成果。     

氯化聚氯乙烯的发展概况

介绍了CPVC的 4种制备工艺 :在卤烃中进行的溶液或悬浮聚合、水相悬浮氯化、固相氯化及用液氯进行的光催化氯化。概述了CPVC的改性情况 ,主要是通过与其它聚合物的共混 (或合金化 )、用无机填料填充、复合以及接枝共聚等方法进行CPVC的改性 ,以提高CPVC的性能。分析了CPVC作为管材、涂料及粘合剂、绝缘及阻燃材料、人造纤维材料、改性剂、泡沫材料等的应用情况。指出了国内CPVC生产企业与国外同类企业之间存在的差距 :规模小 ,成本高 ,质量差 ,产品牌号少 ,推广应用不够 ,多采用溶液法生产 ,悬浮法和固相法生产CPVC量少等 ,这与国内的市场发展极不相配 ,应加大发展力度     

天业集团CPVC工业管成功连续生产

正据了解天业集团自主研发的气固相氯化聚氯乙烯树脂荣获"石油和化工行业绿色产品"认定。该产品采用世界上最先进的气固相法生产工艺,工艺流程简单,无"三废"排放,是一种绿色、清洁、高效的生产方法;为了使产品更好的与市场融合,根据公司领导要求成立了氯化高聚物后加工团队,团队先后对国内外的氯化聚氯乙烯树脂进行了比较分析,同时积极与国内CPVC生产企业合作开发针对气固相法产品的特点开发相应的加工配方,极大的改善了氯化聚氯乙烯树脂加工难度大、塑化不均匀等问题,现在连续生产的CPVC工业管完全符合国家标准的要求。     

苯乙烯氯化原位接枝改性氯化聚氯乙烯的研究

采用氯化原位接枝技术在聚氯乙烯（PVC）进行氯化反应的同时接枝上各种不同单体．从而制备改性的氯化聚氯乙烯（CPVC）。研究了PVC固相法氯化原位接枝St的规律，讨论了单体苯乙烯（St）加入量、氯含量对产物物理力学性能及流变性能的影响。结果表明：St的加入量为10份时，改性CPVC的屈服强度明显高于空白CPVC的屈服强度，但维卡软化点降低；改性CPVC的屈服强度和维卡软化点均随氟含量增加而增大；St的加入量适当，可以同时提高改性CPVC的屈服强度和冲击性能，降低熔体粘度。     

氯化聚氯乙烯及其高性能化进展

氯化聚氯乙烯（CPVC）是PVC重要的改性品种。含氟量为61～68％，制备方法按氯化工艺分为溶液法、水相悬浮法和气固相法。因CPVC熔融粘度高，加工困难，应用受限制。近年来，国外在CPVC的开发方面取得突破性进展，主要集中在制备工艺及新型稳定剂的研究上，对改善CPVC加工性能起到十分重要作用，并通过与其他聚合物的合金化技术，改善CPVC加工流动性，提高抗冲性。目前，CPVC在我国市场还很小，应积极组织力量，加强CPVC稳定剂年攻性剂的研究，CPVC必将具有发展前途。     

水相法氯化聚氯乙烯树脂分子质量的控制

研究了氯化聚氯乙烯树脂（CPVC）平均分子质量与加工耐热稳定性的关系，确定了水相悬浮氯化过程中影响CPVC树脂分子质量的主要因素。结果表明，制备合格的CPVC树脂，除受PVC原料影响外，选择合适的引发剂及其用量、通氯速率可控制CPVC的平均分子质量，氯化反应温度在一定程度上也影响着CPVC树脂的平均分子质量。     

马来酸酐接枝改性氯化聚氯乙烯的制备及其在PVC中的应用

采用固相法制备马来酸酐接枝氯化聚氯乙烯(CPVC-g-MAH),得到了接枝率达2.91 %的CPVC-g-MAH,并对其进行了性能测试,探讨了聚氯乙烯(PVC)/CPVC-g-MAH共混物的冲击性能和加工性能,与PVC/氯化聚氯乙烯(CPVC)共混物进行对比以观察改性效果。结果表明,CPVC-g-MAH的热性能较CPVC有较大提高;PVC/CPVC-g-MAH共混物的冲击性能比PVC/CPVC共混物有所提高,而平衡转矩有所降低,说明CPVC-g-MAH相比于CPVC对PVC共混物加工性能改善效果更加明显。     

水相悬浮法制备氯化聚氯乙烯新工艺

采用水相悬浮法氯化的一种新工艺以大摩尔质量的SG3型国产聚氯乙烯(PVC)树脂为原料,制备高摩尔质量和高氯含量的氯化聚氯乙烯(CPVC)树脂,考察了工艺条件对CPVC摩尔质量和氯含量的影响。结果表明,氯化后产品CPVC的数均摩尔质量Mn和重均摩尔质量Mw值分别为93 174 g/mol和196 153 g/mol,分别大于PVC的88 487 g/mol和186 607 g/mol;在PVC与盐酸溶液固液比25%,反应温度60℃,1,2-二氯乙烷与PVC质量比0.5,偶氮二异丁腈和紫外光双引发,氯气流量0.4 L/min条件下,产品CPVC氯含量最高可达70.86%。该工艺下SG3型PVC树脂可成功氯化,氯化过程分子链没有发生断裂,氯化效率好,达到国外专用PVC树脂的氯化水平。     

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.     

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.     

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。