镁及镁合金环保型阳极氧化工艺研究

研究了镁及镁合金无铬、无磷的环保型阳极氧化工艺测定了镁阳极氧化的稳态伏安曲线和电流密度一时间曲线通过研究氧化电压、电解液中NaOH和Al(0H)3的浓度、电解液温度、氧化时间等对镁阳极氧化成膜的影响，确定了最佳工艺条件分析了最佳工艺条件下得到的镁合金氧化膜的成分、结构与表面形貌，并对镁合金基体与氧化膜的耐腐蚀性能进行了比较结果表明，在环保型阳极氧化液中得到的镁合金氧化膜由镁和铝的氧化物组成，其色泽光滑，结构致密，与镁合金基体相比硬度与耐腐蚀性能都大为提高。     

铝-锂合金阳极氧化及膜层性能的研究

采用恒电压直流方法,在硫酸溶液中铝一锂合金表面能形成阳极氧化膜.用扫描电子显微镜和腐蚀电化学方法研究了添加剂对氧化膜层表面形貌和膜层硬度及耐蚀性能的影响.结果表明:氧化液中加入草酸,氧化膜硬度显著提高;加入草酸和硫酸镍,铝-锂合金阳极化膜层在质量分数为3.5%的NaCl溶液中耐蚀性能最优.     

有机添加剂对AZ31镁合金阳极氧化膜耐蚀性能的影响

在既定的基础电解液和实验参数条件下,研究植酸、聚乙二醇和乙二醇等3种有机添加剂对镁合金阳极氧化膜耐蚀性能的影响.实验过程中分别采用扫描电镜、点滴实验和极化曲线对氧化膜的表面形貌和耐蚀性能进行测试.结果表明:当植酸的质量浓度为15.0 g/L或聚乙二醇的质量浓度为0.8 g/L时,氧化膜的耐蚀性能有较大提高;而乙二醇的加...     

铝阳极氧化着色工艺的研究

分别采用草酸、硼酸和磺基水杨酸为主盐的复合电解液对铝进行阳极氧化着色研究,结果表明:当电压控制在50～60V,溶液温度20～60℃时,可在铝表面形成一层黄色、灰色或香槟色系的阳极氧化膜,氧化膜具有优异的耐蚀性能;电解液组成、阳极氧化峰值电流以及溶液搅拌强度对氧化过程和氧化膜的性能会产生明显影响.     

柠檬酸对AZ31镁合金阳极氧化膜性能的影响

在含NaOH、Na2SiO3和Na2B4O7的电解液体系中对AZ31镁合金进行阳极氧化处理,考察了柠檬酸添加量对阳极氧化膜性能的影响。用扫描电子显微镜观察阳极氧化膜的形貌,用X射线衍射分析氧化膜的结构形态,用电化学交流阻抗谱和动电位极化曲线表征氧化膜对镁合金耐蚀性能的影响。结果表明,柠檬酸的添加有效地抑制了火花放电,得到微孔分布均匀、致密的氧化膜。柠檬酸含量为12 g/L时,所得到的氧化膜具有最大的电荷传递电阻和膜电阻,其腐蚀电位和腐蚀电流密度分别为-1.379 V(相对于饱和甘汞电极)和1.930×10-7 A/cm2,氧化膜对镁合金具有最好的保护作用。     

纳米碳化钛对镁合金阳极氧化过程的影响研究

以纳米碳化钛(TiC)为添加剂,研究其对镁合金阳极氧化过程的作用机制,通过扫描电子显微镜、X射线衍射试验、塔菲尔腐蚀试验等表征氧化膜的形貌结构与性能.结果表明:添加纳米碳化钛能有效改善镁合金的阳极氧化过程,提升镁合金氧化膜的耐腐蚀性能;当添加3～4g·L-1纳米碳化钛时,获得的氧化膜性能最佳.     

锆盐封孔对建筑铝合金阳极氧化膜耐蚀性能的影响

为了改善建筑常用6463铝合金的耐蚀性能,在其表面制备阳极氧化膜,然后采用氟锆酸钾溶液对阳极氧化膜进行封孔处理.研究了锆盐封孔对阳极氧化膜的微观形貌、表面成分和耐蚀性能的影响,并与沸水封孔和镍盐封孔进行了对比.结果表明:锆盐封孔对阳极氧化膜微观形貌的改善效果明显好于沸水封孔,阳极氧化膜中引入Zr元素,质量分数约为19....     

环保型镁合金阳极氧化工艺的研究

研究一种无铬无磷无氟的镁合金阳极氧化工艺.对AZ31B镁合金进行阳极氧化时,在植酸、电流密度和时间不变的条件下,研究了NaOH、Na2SiO3、Na2B4O7不同浓度的16种电解液的阳极氧化膜性能.研究结果表明,组成为NaOH 50g/L、Na2SiO3 60g/L、Na2B4O7 40g/L的电解液,进行阳极氧化得到的氧化膜光滑致密,与基体的结合力强,耐蚀性高,用该电解液对镁合金进行阳极氧化是一种环保型生产工艺.     

镁合金在抑弧状态下阳极氧化研究

采用有机胺、NH4H2PO4、NaF和成膜添加剂组成碱性电解液，对AZ91D镁合金进行了高压阳极氧化研究。结果表明，在抑制阳极发生弧光放电的状态下，镁合金表面可以沉积一层致密的氧化厚膜层，该膜层具有较高的硬度和优良的耐蚀性能。就电解液中各组分在成膜过程中的作用以及电解工艺参数对成膜过程和膜层性能的影响进行了研究探讨。     

聚天冬氨酸对AZ91D镁合金阳极氧化膜性能的影响

为提高AZ91D镁合金耐蚀性且满足绿色环保要求，在阳极氧化电解液中添加环保型添加剂聚天冬氨酸（PASP）制备阳极氧化膜，研究添加剂聚天冬氨酸对阳极氧化过程、氧化膜的形貌及组成和耐腐蚀性能的影响。采用光学显微镜、带能谱的扫描电镜及X射线衍射仪，观察分析添加聚天冬氨酸前后阳极氧化膜的形貌及组成，利用动电位极化及浸泡腐蚀等方法，研究分析阳极氧化后AZ91D镁合金的耐腐蚀性能。结果表明：聚天冬氨酸通过与镁合金表面的吸附作用，使膜层阻抗增大，阳极氧化成膜电压升高，膜厚增大，膜层致密、均匀、平整，微孔和裂纹减少，提高了氧化膜的耐腐蚀性能。     

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。