从生产过氯乙烯树脂的废水中回收氯苯

过氯乙烯树脂是由聚氯乙烯树脂通氯反应后制得。在生产过程中以一氯化苯为溶剂,将聚氯乙烯溶解在氯化苯溶剂中经热氯化后制得过氯乙烯溶液,后者采用水蒸汽蒸馏的方法,使过氯乙烯树脂与一氯化苯溶剂分离     

氯化苯生产中的氯化液除FeCl_3新工艺

通过小试试验确定离子交换树脂脱除氯化液中FeCl_3的可行性,优选出工业化应用最佳树脂型号为SQD-74,树脂运行最佳工艺条件为:吸附温度50℃,交换流量2BV/h,一批氯化液单柱处理量为220BV。用质量分数1%的盐酸顺流对树脂进行脱吸再生,合格后再用去离子水洗涤至出液pH值为2~3,树脂吸附Fe3+能力基本保持不变。对现有水碱洗工艺进行改造,采用一种先进的树脂塔式工艺和连续自动处理装置处理氯化苯生产中酸性氯化液中的FeCl_3,FeCl_3质量分数由(2~5)×10~(-4)降至5×10~(-6)以下,得到的酸性氯化液直接经碱洗、蒸馏后得氯化苯成品。     

CPVC动态热稳定性的影响因素探究

通过试验研究了PVC原料、氯化工艺、CPVC树脂粒径对CPVC树脂动态热稳定性的影响。结果表明：PVC原料和氯化工艺对CPVC树脂的动态热稳定性影响很大,粒径则基本没有影响。     

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。     

过氯乙烯底漆磨浆法生产工艺的研究

介绍了在过氯乙烯树脂液中加入适量醛酮树脂液和二甲苯甲醛树脂,采用磨浆法生产过氯乙烯底漆的生产工艺。     

大孔吸附树脂处理促进剂NS生产废水的工艺研究

研究了H103型大孔吸附树脂对促进剂NS生产废水处理的工艺过程,探讨其吸附-脱附的最佳工艺条件,脱附液再经蒸馏回收叔丁胺。实验结果表明:H103型大孔吸附树脂对促进剂NS生产废水有良好的吸附-脱附效果。经H103型大孔吸附树脂吸附处理后,促进剂NS生产废水中COD去除率达97%以上,达到国家排放标准。对达到泄露点的树脂用甲醇进行脱附,考察了脱附的最佳工艺条件,树脂的脱附率达96%以上,叔丁胺回收率达95%以上。证明该处理工艺可行。     

氯化专用PVC树脂颗粒特性的研究

研究了氯化专用PVC树脂的性能,考察了引发剂、主分散剂、助分散剂、链转移剂、转化率、搅拌等因素对氯化专用PVC树脂颗粒特性的影响。通过综合调整工艺条件可以提高PVC树脂颗粒孔隙率,减少皮膜,控制平均粒径和粒度分布。     

用大孔树脂精制甲醇相中茶皂素影响因素的研究

考察了静态吸附过程中树脂型号、甲醇相溶液pH值、茶皂素质量浓度、吸附温度及时间等因素对大孔树脂吸附性能的影响规律,同时在静态脱附过程中分别改变脱附液浓度、脱附液体积、脱附温度及时间,考察其对脱附率的影响。确定了最佳的吸脱附工艺条件,得出了较优化的操作条件下,树脂吸附量可达145.45 mg/g,脱附率达到90%。     

液体聚丁二烯橡胶的脱挥工艺

将质量分数为10.00%的聚丁二烯橡胶溶液水洗至中性后加热,加热后的胶液经预热器、浓缩器顶部分配盘分配后进入落条式脱挥器的列管中,聚丁二烯橡胶溶液在下落过程中经落条式脱挥器进一步浓缩至质量分数大于25.00%。研究了胶液浓度、进料速度、预热温度、落条式脱挥器的温度及压力等工艺条件,结果表明,落条式脱挥器脱挥工艺适用于液体聚丁二烯橡胶溶液的脱除溶剂,所得产品的微观结构含量与国外同类产品基本相当。     

乙丙橡胶湿法脱挥工艺研究

采用乙丙橡胶(J-2070)胶液进行了凝聚、挤出脱挥的实验研究。采用改造后的喷嘴结构及合理的加料方式,有效地提高了胶液凝聚过程中的脱挥效率。采用改造后的Ⅱ型模头,进行乙丙橡胶水凝聚样品的挤出脱挥实验,实验结果表明:在挤出机模头压力3.6 MPa机头温度为154℃时,挤出样品的w(总挥发分)0.5%;在挤出机转速为50~120 r/min的范围内,挤出样品不发生降解,说明该脱挥工艺可行,满足乙丙橡胶脱挥的要求。     

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.     

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.     

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.     

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.     

Highly moisture-proof polysilsesquioxane coating prepared via facile sol-gel process

A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by ¹H MAS NMR. For direct comparison purposes, an SiO₂ coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N₂ absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.