牙膏中的活性原料综述

本文对牙膏中的一些活性原料进行了综述。对阳离子表面活性剂、摩擦剂、酶及各种维生素在牙膏中的作用进行了研究。     

牙膏中的活性原料

本对牙膏的一些基本要求以及牙膏的组分如表面活性、增稠剂、保湿剂、粘合剂、磨擦剂、甜味剂等进行了讨论。对牙膏中的摩擦剂及粘合剂等进行了介绍。     

摩擦出一口好牙

摩擦剂是牙膏的主要成分,要想有一口好牙,摩擦剂所选用的材料,其颗粒的均匀度以及大小、硬度等,都是选择牙膏时不可忽视的重要指标     

牙膏新型摩擦剂4A沸石与药物牙膏摩擦剂焦磷酸钙的研制

摩擦剂是牙膏的重要组分之一，理想的摩擦剂应具有良好的化学稳定性，不与其它组分发生反应，既能去掉牙斑，又不损伤牙齿的珐瑯质。尤其是药物牙膏中的防龋牙膏，更要求摩擦剂与膏体中的氟具有一定的     

甲基乙烯基醚/马来酸酐共聚物对牙膏稠度的影响

通过测定不同摩擦剂体系牙膏的稠度和对应牙膏液相的黏度,考察了高相对分子质量的甲基乙烯基醚/马来酸酐共聚物分别在以二氧化硅和碳酸钙为摩擦剂的牙膏中的应用,得到了牙膏稠度随时间变化的趋势。研究结果表明,甲基乙烯基醚/马来酸酐共聚物对二氧化硅牙膏的稳定性没有明显影响,而在碳酸钙牙膏中应用时,由于二价钙离子与共聚物中羧酸根负离子的相互作用,改变了牙膏的流变性,导致牙膏稠度逐渐增大,最终令膏体变硬,难以挤出。     

乙烯基甲醚/马来酸共聚物在牙膏中的应用

在牙膏液相和含不同摩擦剂种类牙膏中添加定量的乙烯基甲醚/马来酸共聚物（PVM/MA）,通过加速老化法研究牙膏液相和牙膏黏度、稠度的变化。添加PVM/MA后,不管是牙膏液相还是牙膏成品均表现出的更好的性能,且在不同的摩擦剂体系下呈现出更优异的黏度、稠度以及色度。由于PVM/MA螯合作用的贡献,可有效提高牙膏的初始强度、增加膏体强度,并能提高牙膏稠度,稳定和改善牙膏白度,尤其是钙盐（如碳酸钙、无水焦磷酸钙）为摩擦剂的牙膏。     

3种评价牙膏磨损性能的方法比较

研究比较了表面粗糙度法、ISO11609中附录A的放射性示踪法及附录B的表面轮廓法3种评价牙膏磨损性能的体外实验方法。实验结果表明,对于含有同种类型摩擦剂(二氧化硅或天然碳酸钙)的牙膏试样,表面粗糙度法Ra值的测试结果与放射性示踪法RDA值及表面轮廓法磨损深度的测试结果均具有良好的相关性。同时,与ISO11609中的2种方法相比,表面粗糙度法具有操作简单、刷磨过程压力可控、检测仪器性价比高、数据重复性好、测试结果不易被牙膏配方中磷酸盐等组分干扰等特点。     

儿童牙膏的原料及性能研究

基于儿童牙膏领域国内外的研究成果,系统综述了儿童牙膏生产过程中所使用的原料及其性能研究。着重介绍了摩擦剂、保湿剂、发泡剂、香精及色素、增稠剂、防腐剂和包括含氟物质在内的功能性添加剂的使用情况,并系统分析了各种原料的优劣。总结了儿童牙膏的原料使用现状及其中的问题,展望了未来儿童牙膏的发展方向。     

怎样选择优质的牙膏

牙膏不仅能防蛀及清洁牙齿,且还被赋予了更多的功效,比如美白,预防牙龈疾病,舒缓牙齿敏感等。市场上的牙膏琳琅满目,给消费者很大的选择空间,也同时增加了选择的难度。以下是口腔护理专家在牙膏选择上的一些建议:首先,牙膏所含摩擦剂的不同是辨别牙膏质量的主要依据。牙膏通过磨擦剂去除牙垢,赋予牙齿光泽。一般来说,高档硅磨擦剂工业成本是每吨人民币5400～7000元。但有些厂家采用天然石粉作磨擦剂,每吨不过400元,质量高下不言自明。     

沉淀二氧化硅的性能与应用

沉淀二氧化硅是目前牙膏用摩擦剂的主要品种,用无机酸(或酸性气体)使水溶硅酸盐中的二氧化硅分离、沉淀而制得。     

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.     

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。     

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.