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。     

高耐蚀性镀锌层三价铬蓝白色钝化工艺

开发了一种环保的镀锌层三价铬蓝白色钝化工艺。研究了钝化液中CrCl3·6H2O、Na3C6H5O7、NaNO3、钴盐等成分及pH和温度等工艺参数对钝化膜外观和耐蚀性的影响。蓝白钝化的最佳工艺条件为:CrCl3·6H2O 48g/L,NaNO3 20g/L,Na3C6H5O7 18g/L,钴盐18g/L,室温,pH1.5,钝化时间8s。采用最佳工艺所得钝化膜为光亮、均匀的蓝白色,表面平整、致密,耐蚀性优于镀锌层。     

电镀锌层无铬钝化工艺的研究

开发一种绿色无铬的钝化工艺,所得钝化膜的性能接近铬酸盐钝化膜的。研究了电镀锌层在钛磷硅钼复合体系中的钝化工艺,并采用扫描电子显微镜、硫酸铜点滴实验和中性盐雾实验等方法测试了钝化膜的形貌和耐蚀性。通过正交实验确定了钝化液的最优配方为:三氯化钛10mL/L,磷酸1.8mL/L,硅酸钠18g/L,钼酸钠0.85g/L。其中硅酸钠的质量浓度对钝化膜的表面形貌及耐蚀性的影响最大。采用二次钝化工艺能有效提高钝化膜的耐蚀性。采用上述配方和工艺能够得到一种淡蓝色的无铬钝化膜,其耐蚀性优于三价铬钝化膜的,硫酸铜点滴时间能达到80s,中性盐雾实验的变色时间为72h。     

铝合金镀锌军绿色钝化实践

0前言 镀锌层通过钝化可以得到各种颜色,其中,军绿色钝化由于其独特的装饰效果,优秀的耐蚀能力,受到了人们的重视。不过较少有研究报道在铝合金镀锌层表面获得军绿色钝化膜。目前,我公司根据某国外客户的要求,优化工艺方案．在铝合金镀锌层表面获得了结合力良好、耐蚀性优异的军绿色钝化膜。     

镀锌层军绿色无铬钝化剂的研究

开发了一种无铬军绿色钝化剂,通过单因素试验和正交试验研究了钝化剂的组成(包括硝酸镍、钼酸钠、丙二酸、亚硫酸钠和柠檬酸钠的用量)对钝化膜外观与腐蚀电流的影响,获得了较优的钝化剂配方为:硝酸镍15 g/L,钼酸钠20 g/L,丙二酸12 g/L,亚硫酸钠10 g/L,柠檬酸钠14 g/L。Q235钢碱性锌酸盐镀锌试样在p H为2.0~2.5、温度25~30°C的此钝化剂中钝化20~25 s,得到的钝化膜平整致密,呈军绿色,该钝化膜在(50±5)g/L的Na Cl溶液中浸泡,出现白锈和红锈的时间为16 h和72 h,具有较好的耐蚀性。     

镀锌层单宁酸钝化膜的耐蚀性

为提高镀锌层的耐蚀性,以氟钛酸钾、双氧水、硝酸为辅助成分,制备了单宁酸钝化液,并对低碳钢上的碱性镀锌层进行了钝化处理.通过质量分数为5%的NaCl溶液浸泡试验,确定了最佳钝化液组成和钝化工艺条件为:单宁酸40 g/L,HNO3 5 mL/L,氟钛酸钾10g/L,H2O2 60 mL/L,温度25℃,时间20～30 s....     

稀土钕对镀锌层三价铬蓝白钝化膜耐蚀性的影响

在三价铬钝化液中添加稀土钕,以提高三价铬蓝白钝化膜的耐蚀性。研究了钝化温度、pH、时间以及钝化液中稀土钕含量对钝化膜耐蚀性的影响,得到镀锌层三价铬蓝白钝化的最优工艺条件为:Cr2(SO4)3 18.9 g/L,Nd(NO3)3·6H2O 4 g/L,NaNO32.2 g/L,C6H8O7·H2O 0.7 g/L,CoSO4·7H2O 7 g/L,NaH2PO2·H2O3.4 g/L,NH4HF2 0.2 g/L,温度30°C,pH 1.9,时间30 s。钝化液中添加稀土钕可有效提高钝化膜的耐蚀性。在最佳工艺条件下,钝化膜在3.5%NaCl溶液中的腐蚀电位、腐蚀电流密度和交流阻抗分别为-1.231 V、0.568μA/cm2和1 937?·cm2,中性盐雾试验出现白锈的时间为93 h。     

新型氯化钾镀锌三价铬钝化剂和膜层耐蚀性

通过测定Tafel极化曲线、交流阻抗谱和进行盐雾试验,研究了新型三价铬彩色钝化剂SF-571和蓝白钝化剂SF-572对镀锌层耐蚀性能的影响,并与进口钝化剂进行对比。氯化钾镀锌工艺为:KCl200g/L,ZnCl250g/L,H3BO335g/L,柔软剂30mL/L,光亮剂1.5mL/L,25°C,25min,电流密度2A/dm2。电化学分析表明,所有镀锌层钝化膜在1%NaCl溶液中均存在钝化现象,采用自制钝化剂SF-571和SF-572所得膜层的耐腐蚀性能达到或优于用进口钝化剂所得膜层。对比膜层的表面形貌可知,自制钝化剂钝化所得膜层表面更平整、致密。     

不同镀锌工艺三价铬钝化耐腐蚀性研究

采用中性盐雾试验和电化学阻抗谱,研究了酸性氯化钾镀锌、碱性无氰镀锌和碱性氰化物镀锌3种工艺所得镀锌层经三价铬彩色钝化后钝化膜的耐蚀性.结果表明:钝化后,酸性氯化钾镀锌层的耐蚀性最好,碱性无氰镀锌层次之,碱性氰化物镀锌层最差.在质量分数为1%的氯化钠溶液中,镀锌层钝化膜电阻的大小顺序为:酸性氯化钾镀锌>碱性无氰镀锌>碱性氰化物镀锌.酸性氯化钾镀锌钝化膜的耐蚀性较好可以与所得镀层中有机杂质夹杂较少有关.     

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。     

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。