镁合金AZ91D化学镀前处理工艺的研究

通过正交试验研究了镁合金AZ91D化学镀酸洗液中各因素对试样表面状态、镀速、自腐蚀电流密度的影响,讨论了活化时间对基体表面状态的影响,测试了镁合金化学镀后的耐蚀性和耐磨性.得到了镁合金酸洗的最佳工艺:240 g/L CrO3,40mL/LHNO3(W=68%),酸洗时间30 S.最佳工艺所得镁合金AZ91D化学镀Ni-P镀层的耐蚀性和耐磨性得到了显著提高.     

镁合金磷化工艺的研究

对镁合金进行磷化处理。通过单因素试验和正交试验优化出的最佳磷化液配方及工艺条件为:马日夫盐16.0g/L,Zn(NO3)25.0g/L,NaF 0.090g/L,60℃,18min。经磷化后,镁合金的耐蚀性提高。     

环保型铜件光亮浸蚀新工艺

以H2SO4 900 g/L、Na NO3 100 g/L和Na Cl 1 g/L体系为基础,通过添加整平缓蚀剂和黄烟(NO2)抑制剂,得到了一种操作简单、无黄烟、对基材低腐蚀的铜及铜合金光亮浸蚀新工艺。经过铜片出光效果及黄烟抑制试验,确定聚乙二醇为缓蚀剂、尿素为黄烟抑制剂,用量依次为3~5 g/L和5~10 g/L。研究表明,新工艺中氮氧化物释放量约为旧工艺的22.4%,浸蚀时间在10~120 s、空中停留60 s对试片外观无影响。该工艺适用于自动生产线操作。     

镁合金摩托车零部件的电镀实践

采用自主研发的预处理方法,制定了2种镁合金摩托车零件的电镀工艺.对于形状复杂的AZ91D零件(如发动机外壳),工艺流程为:机械抛光-除蜡-化学除油-CrO3+HNO3酸洗-氢氟酸活化-化学镀镍-电镀焦铜-Cu/Ni/Cr镀层.对于形状简单的AM60零件(如轮毂),工艺流程为:机械抛光-除蜡-化学除油--步酸洗活化-浸锌-预镀镍-电镀焦铜-Cu/Ni/Cr镀层.近2年的试验结果表明,所获得的镀层光亮,结合力好,耐蚀性高,可用于镁合金零件室外环境下的腐蚀防护.     

锆钛转化膜在镁合金车轮上耐腐蚀的研究

为了提高镁合金车轮表面的耐腐蚀性能,研究了锆钛转化膜在镁合金汽车轮毂上腐蚀性能。采用正交试验方法,研究锆钛转化膜工艺影响因素。转化膜处理后进行环氧粉末涂料喷涂,通过附着力、CASS和FILIFORM试验检查涂层性能。通过正交试验得出最佳转化膜处理工艺方案为:碱洗50 g/L,酸洗5.5 g/L,无铬钝化液40 g/L,封闭0.1 g/L,锆钛转化膜提高了镁合金轮毂表面涂层的附着力和耐腐蚀性。     

装饰防护镀铬工艺的正交试验研究

给出了3Ni-Cr装饰防护镀铬的工艺路线。通过CASS试验检测了镀层的耐蚀性。以耐蚀性为评价标准,采用正交试验优化了工艺,发现各因素中Cr^3＋对镀层的影响最大,且得出了最佳工艺为：170g／L CrO3,1．7g/L Cr^3＋,1．5g/L H2SO4,pH2．5,θ50℃,J15A／dm^2。介绍了工艺的维护与管理,包括控制CrO2与H2SO4的质量比及Cr^3＋的含量,阳极与电源的要求,抑雾剂的使用等。该工艺性能稳定,镀层光亮,致密,平整,耐蚀性高。     

镁合金复合化学镀(Ni-P)-Si3N4复合镀层工艺研究

通过复合化学镀的方法在镁合金表面制备(N i-P)-Si3N4复合镀层,主要研究了镀液中颗粒含量、温度、pH等工艺参数对复合镀层表面形貌及显微硬度的影响。结果表明,获得良好表面微观形貌和较高显微硬度的纳米复合镀层的工艺参数为:θ=80℃、pH=8.5,ρ(Si3N4)为7~9 g/L。     

AZ91镁合金化学转化膜的制备及耐蚀性能的研究

在AZ91镁合金表面采用化学方法制备转化膜层。对植酸化学转化溶液中植酸质量分数,pH,反应温度,反应时间等进行单因素实验和正交试验,确定最佳工艺参数:3 mL/L植酸,3 g/L NaF,40 g/L H3BO3,15mL/L H2O2,pH为4.5。在镁合金表面获得淡灰致密,具有微细裂纹的膜层。在植酸化学转化溶液中添加5g/L Ce(NO3)3·6H2O获得更为优异的耐蚀膜层。通过X-射线衍射测试表明,添加Ce(NO3)3·6H2O的镁合金化学转化膜的主要成分为MgH10O24P6和CeO2。耐蚀性测试表明,两种溶液获得的镁合金化学转化膜的耐蚀性能均有提高,其中添加硝酸铈的膜层微观形貌及性能较佳。     

四酸型镀锌层军绿色钝化工艺

提出了一种镀锌层四酸型军绿色钝化工艺。研究了钝化液中4种酸的含量和钝化时间对钝化膜外观和耐蚀性的影响。确定最佳工艺条件为:CrO36g/L,H3PO42mL/L,H2SO42mL/L,H3NO33mL/L,温度25℃,pH1.5,钝化时间100s。所得钝化膜为光亮的军绿色,耐蚀性较镀锌层好。     

镁合金植酸转化膜的制备及其性能的研究

采用化学转化方法在AZ91D镁合金表面制备一种环境友好型的植酸转化膜。通过对pH值、温度、反应时间、植酸的质量分数等因素的控制,进行单因素实验和正交实验。确定的最佳工艺条件为:植酸3%,NaF 3g/L,H3BO340g/L,Ce(NO3)3·6H2O 5g/L,pH值4.5。采用优化后的工艺,能够在镁合金基体表面获得宏观上淡灰、致密,微观上具有微细裂纹的膜层。XRD测试表明:该植酸转化膜的主要成分为MgH10O24P6和CeO2。耐蚀性测试表明:植酸转化膜能有效地提高镁合金的耐蚀性。     

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。