电解氧化4-甲基吡啶合成异烟酸

以Ti基PbO2 为阳极 ,Cu或Ni为阴极 ,在硫酸介质中 ,电解氧化 4 甲基吡啶合成了异烟酸。经过实验确定的最佳合成条件为 :c(硫酸 ) =4 6 0mol/L ,c(4 甲基吡啶 ) =0 6 0mol/L ,电解电流密度i=6 0mA/cm2 ,t=6 0℃。在此条件下 ,异烟酸的收率为 6 4 6 % ,电流效率为 6 7%。同时还研究了电解过程中反应物转化率、电流效率、槽压的变化规律。经示波极谱、红外光谱和熔点测定法证明电合成的物质为异烟酸 ,质量分数为 97 7%。     

2甲-基吡啶在丙酮-水混合溶剂中的电氧化

在质子交换膜为隔膜的电解槽内,以2甲-基吡啶为原料,在丙酮/水混合溶剂中,以PbO2为阳极,电氧化合成了2-吡啶甲酸。通过循环伏安、线性扫描伏安和恒电位电解实验,考察了丙酮与水体积比、反应温度、硫酸浓度、反应物2-甲基吡啶浓度和阳极电位对选择性和电流效率的影响。结果表明,V(丙酮)∶V(水)=3∶1,硫酸浓度1.0~1.2 mol/L,2甲-基吡啶浓度0.5 mol/L,温度30℃,阳极电位1.75~1.80 V,生成2吡-啶甲酸的选择性可达88.7%,电流效率达到48.3%。而在纯水作溶剂的溶液中,相同条件下生成2-吡啶甲酸的选择性和电流效率仅分别为67.4%和42.2%。     

4-甲基吡啶直接电氧化合成异烟酸工艺条件的研究

以Ti/PbO2为阳极,Pb为阴极,硫酸溶液为电解质,在阳离子交换膜为隔膜的H型电解槽中,直接电氧化4-甲基吡啶合成异烟酸,并考察了阳极电解液中4-甲基吡啶及硫酸浓度,通电量,电流密度和温度对异烟酸收率和电流效率的影响,得到的工艺条件为阳极电解液中4-甲基吡啶和硫酸的质量分数分别为10%和25%,通电量18.65(A.h),电解电流密度60 mA/cm2,60℃,在此条件下重复试验,异烟酸平均收率达到92.2%,平均电流效率50.9%。     

十二烷基苯磺酸钠对2-甲基吡啶电氧化的影响

通过恒电位电解实验,在以质子交换膜为隔膜的电解槽内,将十二烷基苯磺酸钠(SDBS)添加于2-甲基吡啶电氧化的有机合成体系中,研究了2-甲基吡啶在PbO2电极上的电氧化行为。通过实验确定最佳条件为:2-甲基吡啶浓度为0.5mol·L-1,H2SO4浓度为1.0mol·L-1,丙酮/水(3∶1)为溶剂,阳极电位为1.8V,反应温度为30℃,SDBS浓度为1.6×10-3mol·L-1,电解理论电量的20%,其选择性为81.98%,电流效率为59.32%。在该实验环境下,SDBS对2-甲基吡啶电氧化有明显的促进作用,选择性和电流效率都有明显的提高。     

Ce~(4+)/Ce~(3+)做氧化媒质间接电合成邻氯苯甲醛

用硫酸做介质、Ce4 + Ce3+ 做氧化媒质间接电合成邻氯苯甲醛。通过正交实验和单因素实验确定出最佳工艺条件为 :反应温度 348K ,表面活性剂浓度 1 .4× 1 0 - 3～ 2 .2× 1 0 - 3mol L ,硫酸浓度 7.5mol L。在优化的实验条件下邻氯苯甲醛的产率达 93.1 % ;在相应的电解实验中 ,电流效率为 89.46% ,电解收率为 50 .1 5%。     

成对电合成葡萄糖酸及山梨醇的研究

采用成对合成新工艺电解葡萄糖制取葡萄糖酸及山梨醇 ,研究了电流、温度、介质浓度、葡萄糖浓度及电解时间对葡萄糖电解过程的影响。结果表明 ,在电流密度为 1mA/cm2 ,温度为 2 5℃ ,c(硫酸 ) =0 .30mol/L介质中 ,浓度为 3.6× 10 -2 mol/L的葡萄糖电解 90min后 ,其转化率可达 90 %。     

Ce4+/Ce3+作氧化媒质间接电氧化对氯甲苯的反应动力学研究

在优化的实验条件下分别从产物和反应物2方面进行分析，系统地研究了硫酸浓度为6．425mol/L和7．7mol/L时Ce^4 /Ce^3 作氧化媒质间接电氧化对氯甲苯的有机氧化动力学，确定出总反应为 表观1级反应，并拟合出了相应的表观反应速率常数和表观活化能，当硫酸介质浓度从6．425mol/L增至7．7mol/L时表观活化能显著降低（从122－128kJ/mol降低到84－89kJ/mol）从而大大加速了化学反应速率。     

间接电解氢化法合成L—磺基丙氨酸

Nafion417为隔膜的电解槽中，DSA(dimensional stable anode)为形稳性阳极，Pb为阴极，间接电解氧化L—胱氨酸合成L—磺基丙氨酸。研究了胱氨酸浓度、HBr浓度、电解浴温度、阳极电流密度及电解电量等因素对电合成L-磺基丙氨酸产率的影响。研究表明：由0．1mol/L胱氨酸和3．5mol/L HBr组成的阳极液，以2．5A．dm^-2的电流密度于30℃电解至理论电解电量为止，产品产率达70％。     

Co~(3+)的电氧化合成及其在对甲砜基苯甲酸制备中的应用

以七水硫酸钴、浓硫酸、硫酸铵为原料,电氧化合成Co3+,用Co3+氧化对甲砜基甲苯合成对甲砜基苯甲酸。考察了电极材料、电解温度、电流密度、硫酸浓度以及电解液循环套用对电极反应和硫酸浓度、Co3+与对甲砜基甲苯物质的量比对氧化反应的影响。结果表明,在选用阳极二氧化铅、阴极铅为电极板,陶瓷膜作为阳离子交换膜,电解液浓度为c(Co2+)=0.5 mol/L、c (硫酸)=4.0 mol/L、c (硫酸铵)=0.15 mol/L,电极间距(d)为2 cm、电流密度(J)为350 A/m2、电解温度(T)为10℃时,电解液Co2+转化率可达80%,电解氧化电流效率达67.5%。在进行对甲砜基甲苯的氧化时,控制电解液浓度为c(Co3+)=0.4 mol/L、c(硫酸)=4.0 mol/L、c(硫酸铵)=0.15 mol/L,n(Co3+)∶n(对甲砜基甲苯)=6∶1,使得反应温度为30℃,反应时间为30 min,对甲砜基苯甲酸的收率可达97.8%,精制后纯度在98.5%以上。     

牙膏磨擦剂二氧化硅制备条件的优化

以硅酸钠和硫酸为原料,采用硫酸沉淀法,合成适用于牙膏以及透明牙膏的SiO2。首先考察了釜底液硅酸钠浓度、温度以及陈化时间对SiO2性能的影响。结果表明：当釜底液中硅酸钠浓度为0.13mol/L、合成温度为65℃以及陈化时间为30min的条件下,合成SiO2的透光率可以达到89%。随后,以提高透光率为目标研究了在釜底液中添加Na2SO4、NaCl两种电解质对SiO2性能的影响。结果表明：在合成温度为65℃的条件下,添加浓度为0.04～0.12mol/L的Na2SO4、NaCl对合成SiO2的透光率基本上没有影响;而在合成温度为85℃的条件下,添加浓度为0.08mol/L的Na2SO4合成SiO2的透光率可以达到97%,添加浓度为0.12mol/L的NaCl合成SiO2的透光率可以达到96%。造成这种现象的可能原因是：在相对高的合成温度下,电解质能够更加有效的参与到硅酸的聚合中,使得SiO2的透光率得到一定的改善。按照QB/T 2346—2007对所合成的物质的牙膏磨擦剂特性进行测定,达到了标准要求。     

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.     

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.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008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、不饱和聚酯树脂、环氧树脂)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.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006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生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。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（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。