二乙基二茂铁合成工艺的研究

以三氯化铝为催化剂,溴乙烷为烷基化剂,利用二茂铁的Friedel-crafts反应合成出了二乙基二茂铁,探讨了反应温度、物料摩尔比、反应时间、催化剂用量及投料方式对反应的影响,确定了适宜合成工艺:二茂铁、溴乙烷和无水三氯化铝的摩尔比为1∶2.2∶(1.88~1)∶2.2∶2.0,反应温度45℃,反应6.5 h,通过元素分析、红外谱图对产物进行了表征,产率达72%。     

四甲基二苯乙烷的合成研究

经傅──克烷基化反应合成了四甲基二苯乙烷，讨论了各反应条件对反应的影响．得出了最佳反应条件：n（邻二甲苯）：n(1，2-二氯乙烷）：n（无水三氯化铝）为10：1:1.8(mol:mol:mol)；反应温度，80±2℃；反应时间，2~3h。反应收率达到78%，产品纯度为965％以上．     

苯甲醛直接氯化法合成间氯苯甲醛

以苯甲醛为原料直接氯化合成间氯苯甲醛,通过对几种可能的催化剂进行比较,选择了无水三氯化铝作为该氯化反应的催化剂;用单因素方法和正交实验考察了原料液浓度、催化剂用量、反应温度和反应时间对氯化反应的影响,得到了氯化反应优惠条件:苯甲醛1 33mol/L,无水三氯化铝1 70mol/L,反应时间30min,反应温度50℃。苯甲醛的转化率≥90%,间氯苯甲醛的收率≥79%,选择性为88%,氯化产品中基本无同分异构体。     

十溴二苯乙烷分段催化工艺及复配催化剂的研究

研究了十溴二苯乙烷分段催化的合成工艺及复配催化剂。结果表明,催化剂采用Al粉、P_2O_5、无水AlCl_3和无水TiCl_4等进行复配,不同催化剂组合在反应过程中分为三个阶段投入,第一、第二和第三阶段催化剂投料质量占成品十溴二苯乙烷理论产量的0.12%、0.12%和0.15%,分别控制不同阶段的反应温度和反应时间能显著提高产品质量,降低杂质含量。     

抗氧化剂5057(N-苯基苯胺与2,4,4-三甲基戊烯的反应物)的制备研究

抗氧化剂5057是一种耐高温油溶性胺类链终止型抗氧剂。以2,4,4-三甲基戊烯和二苯胺为原料,无水三氯化铝、甲苯及1,2-二氯乙烷制备出的配合物为催化剂合成出抗氧化剂5057。实验结果表明,制备催化剂较佳反应条件为:甲苯与1,2-二氯乙烷物质量比为2.1∶1,制备温度为25℃,反应时间为3h。烷基化反应合成目的产物的较佳条件为:2,4,4-三甲基戊烯和二苯胺物质量比为5∶1,催化剂加入量为5%,反应温度85℃,反应时间4h,产物后处理水解温度为50~60℃,产物5057的收率可达88.2%,并通红外光谱对产物进行了表征。     

2-溴乙氧基苯的相转移催化合成研究

在四丁基溴化铵相转移催化剂存在下,以苯酚、1,2-二溴乙烷为原料合成2-溴乙氧基苯,分别研究了反应温度、反应时间、原料配比、催化剂用量等条件对合成反应的影响,确定了最佳工艺条件。该方法合成2-溴乙氧基苯的最佳工艺条件是:反应温度100°C;反应时间6 h;n(苯酚)∶n(1,2-二溴乙烷)=1∶1.15;n(苯酚)∶n(氢氧化钠)=1∶1.15;溶剂用量为40 mL(相对于0.15 mol苯酚),催化剂用量为1 g(相对于0.15 mol苯酚),2-溴乙氧基苯的收率可达到88.9%以上,产品纯度98.5%。     

碘化钠催化合成1,4-二乙氧基苯的研究

以乙醇为溶剂，碘化钠为催化剂，由金属钠，对苯二酚和溴乙烷合成了1，4－二乙氧基苯，考察了影响收率的因素，最佳合成条件为：物料溴乙烷：对苯二酚：金属钠：碘化钠（摩尔比）为2．5：1：2．2：0．13，反应在回流温度下进行，反应时间2h，收率可达92．8％。     

C9芳烃中均三甲苯与邻甲乙苯的分离研究

介绍了均三甲苯分离技术的新发展,研究开发了一种新工艺,以叔丁醇为烷基化剂,无水三氯化铝为催化剂,通过傅-克烷基化反应将邻甲乙苯转化成沸点较均三甲苯高的重组分,使二者能通过常规精馏的方法得以有效地分离。研究了反应温度、原料配比、催化剂用量等反应条件对烷基化反应的影响,烷基化反应的最佳工艺条件为室温、反应时问2～4h、C9芳烃与烷基化剂(叔丁醇)及催化剂的摩尔配比为1：1：0．4,可使邻甲乙苯100%转化,而均三甲苯损失率小于2％。     

吩噻嗪合成的工艺研究

以二苯胺和硫磺为原料,以碘和无水三氯化铝作催化剂合成吩噻嗪,讨论了原料配比、反应温度、反应时间、催化剂的用量对合成反应的影响,并对比了两种催化剂的效果。实验表明,原料二苯胺和硫磺的摩尔比为1∶1,加入二苯胺质量1%的碘粒作为催化剂,反应温度一般宜控制在443~453K之间,最佳的反应时间是60min左右。对产品进行了红外、紫外表征分析确认。认为开发新型固体酸催化剂应成为新的研究方向。     

N-乙基哌嗪的合成研究

提出以哌嗪和溴乙烷为原料进行烷基化反应制备N 乙基哌嗪的合成路线 ,研究了原料与烷化剂的物质的量比、反应时间、反应温度、催化剂种类等因素对产品收率的影响。并确定了最佳反应条件。在最佳条件下 ,N 乙基哌嗪收率大于 90 % ,经分离精制得w(N 乙基哌嗪 ) =99%的产品。     

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.     

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.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.