焦磷酸盐溶液体系电沉积铜及铜–锡合金的电化学行为

采用电化学测试方法研究了焦磷酸盐溶液体系在铜电极表面电沉积Cu及Cu–Sn合金(低Sn)的电化学行为。探讨了添加剂JZ-1对电沉积Cu和Cu–Sn合金的影响,并对电沉积层的表面形貌和晶相结构进行分析。结果表明,焦磷酸盐溶液体系电沉积Cu及Cu–Sn合金均为不可逆电极过程,发生电化学极化。电沉积Cu的阴极过程表现为前置转化反应很快和以CuP22 O-7直接还原的反应机理形式。电沉积Cu–Sn合金过程中Cu与Sn之间存在相互作用,溶液中的Cu2+与Sn2+也存在相互促进电沉积的作用,Cu–Sn合金的晶相结构为Cu13.7Sn。添加剂JZ-1具有促进Cu电沉积和抑制Sn电沉积的双重作用,有利于降低Cu–Sn合金中的Sn含量并细化晶粒。     

焦磷酸盐溶液体系电沉积白铜锡的电化学行为

通过测定阴极极化曲线和循环伏安曲线,研究了焦磷酸盐溶液体系在铜电极上电沉积白铜锡的电化学行为,并分析了不同添加剂对电沉积白铜锡阴极过程和电沉积层晶相结构的影响。结果表明,焦磷酸盐溶液体系电沉积白铜锡为不可逆电极过程,溶液中Cu2+与Sn2+也有互相促进电沉积的作用。添加剂IEP、DPTHE和JZ-1都会影响溶液中Cu2+和Sn2+离子还原的阴极极化和电沉积白铜锡的晶相结构。IEP和JZ-1都具有增强Sn2+还原的阴极极化和降低Cu2+还原的阴极极化的双重作用。无添加剂和添加IEP或DPTHE的镀液中电沉积所得白铜锡的晶相结构都为Cu6Sn5,添加JZ-1的镀液中电沉积所得白铜锡的主要晶相结构则为Cu41Sn11。     

HEDP溶液体系电沉积铜的电化学行为

采用循环伏安曲线法和阴极极化曲线法研究了0.388 mol/L HEDP(羟基亚乙基二磷酸)+0.160 mol/L Cu SO4·5H2O溶液体系(p H=9.3或9.5)电沉积铜的电极过程动力学规律和添加剂对阴极极化的影响。结果表明,HEDP溶液体系电沉积铜是Cu2+的一步放电还原,遵循无前置化学转化反应或前置化学转化反应很快的不可逆电极过程动力学规律。添加剂HES(含硒无机化合物)和复配添加剂HES+HEA(多胺高分子聚合物)具有促进电沉积铜和抑制析氢的双重作用,提高了HEDP溶液体系电沉积铜的阴极电流效率。     

氯化胆碱-乙二醇低共熔溶剂中锡沉积的电化学行为

[目的]研究氯化胆碱与乙二醇物质的量比为1∶3的低共熔溶剂(用ChCl-3EG表示)中Sn(Ⅱ)电沉积的电化学行为及所得Sn镀层的耐蚀性,并将测试结果与氯化胆碱与乙二醇物质的量比为1∶2的体系(用Ch Cl-2EG表示)进行对比。[方法]先通过循环伏安法研究了Sn(Ⅱ)在ChCl-3EG体系中的电化学还原过程,研究了温度和主盐浓度对其电化学行为的影响。采用计时电流法研究了该体系中锡的形核生长机理,通过塔菲尔极化曲线测试研究了所得Sn镀层的耐蚀性,使用扫描电镜分析了Sn镀层的微观形貌。[结果]Sn(Ⅱ)在ChCl-3EG体系中的电化学还原是受扩散控制的不可逆过程。Sn(Ⅱ)在60°C的ChCl-3EG体系中的扩散系数为1.22×10^-6 cm²/s,与在ChCl-2EG体系中的扩散系数接近,但前者的扩散活化能明显更低。Sn(Ⅱ)的电结晶过程为三维瞬时形核,适当增大阴极电流密度有利于提高Sn镀层的耐蚀性。[结论]Sn(Ⅱ)在物质的量比为1∶3的氯化胆碱-乙二醇体系中更容易还原,能耗更低,得到的Sn镀层具有优异的耐蚀性,可作为电沉积或电解精炼锡的电...     

添加剂对无氰电镀铜-锡合金(低锡)镀层性能的影响

通过赫尔槽试验与直流电解试验,研究了添加剂在焦磷酸盐溶液体系无氰电镀铜-锡合金(低锡)工艺中的作用。该体系镀液组成与工艺条件为:Cu2P2O7·3H2O25g/L,Sn2P2O71.0g/L,K4P2O7·3H2O250g/L,K2HPO4·3H2O60g/L,温度25℃,pH8.5,电流密度1.0A/dm2。采用扫描电镜(SEM)、X射线衍射(XRD)、能谱(EDS)、中性盐雾试验等方法研究了添加剂对镀层组成结构、外观、耐腐蚀性能及微观形貌的影响。结果表明,焦磷酸盐溶液体系无氰电镀铜-锡合金(低锡)时使用有机胺类添加剂可抑制Sn的析出,使合金镀层致密均匀,耐蚀性能好。镀层结晶主要为Cu13.7Sn结构,镀层中Sn含量为9%～11%。镀液中添加剂的使用量增加,则合金镀层中的Sn含量降低。     

ZnCl2–NH4Cl溶液中锌配合离子的阴极还原

采用多种电化学方法探讨了ZnCl2–NH4Cl溶液配制液中精炼锌的阴极过程. 结果表明：Zn(II)离子在ZnCl2–NH4Cl溶液配制液中阴极还原生成金属锌的电极过程，具有两电荷放电一步完成和电荷转移控制的不可逆电极过程动力学规律，Zn(II)离子在此溶液配制液中主要以[Zn(NH3)4]2+配合离子存在，而直接在阴极放电的配合离子物种是[Zn(NH3)2]2+.     

无氰铜锡合金仿金电镀添加剂的研究

通过赫尔槽试验和方槽试验研究了添加剂H-3、DDS和JZ-1对焦磷酸盐溶液体系电镀仿金铜锡合金性能的影响。基础镀液组成为:K4P2O7·3H2O 240 g/L,Sn2P2O7 2.0 g/L,Cu2P2O7·3H2O 24 g/L,p H 8.7。结果表明,采用焦磷酸盐溶液体系电镀铜锡合金时,只有用到添加剂方可得到仿金镀层。添加剂H-3具有一定的整平、细化晶粒和提高光亮度的作用。H-3的用量为2.8 m L/L时,在黄铜基体上获得仿金镀层的阴极电流密度范围为0.29~2.25 A/cm2。焦磷酸盐溶液体系使用添加剂H-3时,在光亮酸铜、光亮镍、无氰白铜锡中间层上和直接在钢铁基体上进行仿金电镀时,均可获得光亮的仿金镀层。     

锌催化电还原脱氯合成2,3,5,6-四氯吡啶:反应机理和工艺优化

采用循环伏安法和恒电位电解法,探讨了含有ZnCl_2的乙睛水混合溶液中五氯吡啶(PCP)在不锈钢阴极表面电还原脱氯生成2,3,5,6-四氯吡啶(2,3,5,6-TCP)的反应机理;采用恒电流电解法对该电还原脱氯过程的各种工艺条件进行了优化。结果表明:该体系中PCP电还原脱氯生成2,3,5,6-TCP主要遵循以Zn/Zn~(2+)为氧化还原媒介的间接电还原机理;优化工艺条件下(阴极液含0.025 mol·L~(-1)HCl+15%(体积分数)水+0.2 mol·L~(-1)苯磺酸钠+0.16 mol·L~(-1) ZnCl_2的乙腈溶液;电流密度为1.25 A·dm~(-2)),0.08 mol·L~(-1) PCP能高选择性地脱氯生成2,3,5,6-TCP,2,3,5,6-TCP的收率和电解电流效率分别可达88.7%和59.1%。     

HEDP(羟基乙叉二膦酸)镀铜机理的研究

本文对HEDP—Cu~(2 )体系中的络合状态进行了研究。用pH法求得了[Cu(H_2L)_2]~(2-)、[Cu(HL)_2]~(4-)、[CuL_2]~(6-)的逐级稳定常数。在HEDP镀铜体系中,Cu~(2 )主要形成[CuL_2]~(6-)络离子。用旋转园盘电极研究了铜的电析机理。对于所有试验溶液,极化曲线都可以分为二个电势区域。在电位比E_b(相对参考电极约-0.78V)较负的区域,已无[L~(4-)]在电极表面吸附,E与Logi成直线关系,斜率几乎与[L~(4-)]、[CuL_2]~(6-)浓度无关。交换电流密度i_0随Log[CuL_2~(6-)]增加而增加,随Log[L~(4-)]增加而减少。在HEDP镀铜浓度范围内,电析机理为: CuL_2~(6-)■CuL~(2-) L~(4-) CuL~(2-) 2e→Cu L~(4-)。     

添加剂在铜电解精炼中的电化学行为的研究

用稳态法和循环伏安法研究添加剂Cl-、glue、(NH2)2CS在铜电解精炼中的电化学行为.研究表明:当Cl-、glue、(NH2)2CS单独存在于电解液中时,Cl-对铜沉积反应起去极化作用,glue对铜沉积反应起极化作用,(NH2)2CS能使铜沉积反应出现由扩散控制的极限电流;当硫脲浓度为6.0mg·L-1时,铜沉积反应的循环伏安图中出现Cu2+被还原的1个阴极峰,浓度为12.0mg·L-1时,图中出现Cu2+和[Cu(TU)n]2+均被还原的2个阴极峰,浓度为25.0mug·L-1时,图中出现[Cu(TU)n]2+被还原的1个阴极峰.当Cl-1、骨胶、硫脲共存于电解液中时,对铜沉积反应起强烈的极化作用,使铜沉积反应的极限电流密度降低.     

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。