镀锌层高耐蚀三价铬黑色钝化工艺

采用正交试验优化镀锌层三价铬黑色钝化液的各个组分,在此基础上考察各种工艺条件对钝化膜的外观、耐蚀性和附着力的影响,确定了三价铬黑色钝化工艺的配方及工艺参数。三价铬黑色钝化工艺为:7.5 g/L Cr~(3+),21 g/L络合剂,22 g/L磷酸二氢钠,15 g/L过渡金属盐,0.4 mL/L有机硫化物,0.4 mL/L纳米硅溶胶,pH为2.0,θ为50℃,钝化t为45 s。该钝化工艺得到的钝化膜均匀黑亮,附着力良好,在未加封闭的情况下,耐蚀性达到中性盐雾60 h以上。     

热镀锌板三价铬钝化膜的耐蚀性分析

为了提高热镀锌板的耐蚀性,提出了一种新型三价铬钝化工艺,并将其与传统六价铬钝化工艺进行了比较。采用中性盐雾试验及电化学方法研究了钝化膜的电化学腐蚀行为,并利用扫描电镜观察了钝化膜的表面形貌。结果表明:热镀锌板经钝化处理后耐蚀性提高;三价铬钝化膜表面平整、结构致密,无明显裂纹,耐盐雾腐蚀时间长达84h,较六价铬钝化膜具有更好的耐蚀性。     

镀锌层硅酸盐钝化工艺研究

采用盐雾试验测试锌镀层钝化膜的耐蚀性,研究了镀锌层硅酸盐钝化的工艺条件。实验结果表明,在pH 3.0、温度30℃、钝化时间90 s的钝化工艺条件下,硅酸盐钝化液组成为硅酸钠40 g/L、98%硫酸4 mL/L、30%过氧化氢40 mL/L、硫脲7 g/L、67%硝酸2 mL/L、85%磷酸2 mL/L时,镀锌层钝化膜具有较强的耐蚀性。     

Zn-Ni合金镀层的黑色钝化工艺研究

在含M为10％～14％的Zn-Ni合金镀层上先钝化再进行封闭处理,可获得色泽均匀、结晶细致的转化膜、讨论了钝化工艺条件及封闭剂、pH值对转化膜耐蚀性的影响：经过正交实验和单因素实验,确定了最佳钝化配方为：40g/L铬酐、40mL／L醋酸、10g/L成膜促进剂、0．45h/L硝酸、温度20℃、时间30～40s。研究了封闭条件,确定的封闭剂的组成为：120～220g/L硅酸钠,1～3g/L氟化钠,0．1～0．3g/L硫酸锂,最佳pH值为10．5硫酸铜点滴实验、中性盐水浸泡实验、扫描电镜以及交流阻抗测试表明：Zn-Ni合金镀层先经钝化再经封闭处理后耐蚀性能明显提高：该钝化工艺操作简单,具有应用价值．     

氯化铬对热镀锌板三价铬钝化膜的影响

采用中性盐雾试验、醋酸铅点滴试验以及电化学极化和阻抗测试方法,研究了不同浓度的氯化铬对热镀锌板三价铬钝化膜耐蚀性能的影响;采用金相显微镜观察了钝化膜极化后的腐蚀形貌。研究表明,钝化膜中以Cr Cl3·6H2O为主要成膜物,当浓度在0.6~1.0 mol/L时,钝化膜耐中性盐雾试验和醋酸铅点滴时间最长,在3.5%Na Cl溶液中腐蚀电流最小、低频阻抗值最大,并分析了氯化铬浓度对钝化膜耐蚀性的影响。     

镀锡板有机钝化工艺的研究

采用有机钝化体系对镀锡板进行钝化处理。通过点滴试验和电化学测试对钝化膜的耐蚀性进行检测,并用扫描电子显微镜观察了钝化膜的表面形貌。得到的较优工艺配方为十二烷基磺酸钠4.5g/L+植酸6.0g/L。所得钝化膜的自腐蚀电流密度最小,为1.235×10~(-6)A/cm~2;极化电阻最大,为5 094.1Ω;自腐蚀电位正移0.117V;点滴时间增加20s。采用该钝化工艺能提高镀锡板的耐蚀性。     

镀锌层高耐蚀彩钝工艺

采用正交实验确定了镀锌钝化最佳工艺配方为14g/LCrO3,5g/L辅助钝化剂MH,5g/L HNO3,7g/L ZnSO4,0.7g/L KMnO4.研究了各工艺参数对钝化膜的影响.该钝化液性能稳定,使用寿命长;膜层为彩虹色,耐蚀性好.醋酸铅（ρ=50g/L）点滴实验氰化镀锌钝化层出现黑点的时间为98 s;NaCl（w=3%）溶液中浸泡,出现白锈时间为37 h;中性盐雾实验出现白锈时间在140 h以上。     

钝化工艺对无氰镉-钛合金镀层性能的影响

为了获得无氰镀镉-钛合金的最佳后处理工艺,利用金相显微镜、电化学工作站和盐雾试验测试了三种钝化膜的外观及耐蚀性,并进行了比较。实验结果显示,三种钝化工艺获取的钝化膜经96 h中性盐雾试验后,均未出现白锈;电化学测试结果显示低铬钝化工艺获取的钝化膜自腐蚀电流密度最大,重铬酸钠钝化工艺获取的钝化膜自腐蚀电流密度最小。从环保和耐蚀性方面考虑,建议选用重铬酸钠+硝酸钝化工艺作为无氰镉-钛合金镀层的后处理工艺。     

辅助成膜剂对锌酸盐镀锌蓝白钝化外观的影响

镀锌蓝白钝化膜的颜色相比彩色钝化单一,钝化膜的颜色更易受到金属离子的影响,辅助成膜剂可以提高镀锌钝化膜的致密性和耐蚀性,改变钝化膜的颜色。研究发现,在三价铬基础钝化液中添加适量的硫酸钴,能增加蓝白钝化膜的蓝色并延长硫酸铜点滴试验的变色时间,但对增强钝化膜的抗盐雾性能不明显;加入适量的氯化镍,能改善蓝白钝化膜的外观,但不显著;加入0.5~2.0 g/L的镧离子对蓝白钝化膜外观没有明显的改善作用。硅酸钠虽然能提高钝化膜的耐蚀性,但增大了钝化试样的杂色,使得钝化膜的颜色不均匀。     

高性能无铬钝化技术

介绍了ZECCOAT无铬钝化工艺.该工艺采用了高科技纳米技术,钝化液无毒,钝化膜薄且具有自修复性,钝化产品的耐蚀性高.生产实践表明:ZECCOAT无铬钝化的成本与传统三价铬钝化加封闭工艺的大体相同.中性盐雾试验结果表明:采用三价铬钝化+ ZECCOAT无铬钝化与直接采用ZECCOAT无铬钝化相比较,产品的耐蚀性得到了明显的提高.     

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。