硅烷偶联剂表面修饰四针状氧化锌晶须

利用硅烷偶联剂KH-570对四针状氧化锌晶须T-ZnOw表面进行了修饰,探讨了改性条件对改性效果的影响。用活化指数确定了改性的最佳工艺条件:盐酸为催化剂,水解时间1 h,偶联剂用量4%(相对于晶须用量),偶联温度70℃,偶联时间2 h。FTIR分析表明,偶联剂分子与晶须表面的羟基发生化学反应来实现对晶须的表面修饰,修饰后晶须疏水性明显增强。采用亲油化度、分散性实验对修饰前后T-ZnOw进行了表征。结果表明,改性样品分散性和亲油化度都得到显著改善。     

掺杂型ZnOw/纳米ZnO并用对PP性能的影响

研究了铝掺杂氧化锌晶须(ZnOw)和纳米ZnO对聚丙烯共混物力学性能和抗静电性能的影响.结果表明,铝掺杂氧化锌晶须能提高聚丙烯的冲击强度、拉伸强度和表面电阻率.纳米ZnO与掺杂氧化锌晶须并用能协同增强和增韧聚丙烯,纳米ZnO/掺杂氧化锌晶须/聚丙烯的质量比为2/16/82时,共混体系的综合力学性能较好.     

四针状氧化锌晶须的表面改性

分别用硅烷偶联剂KH550、KH560和KH570对四针状氧化锌晶须进行表面改性研究,考察偶联剂的用量、处理方法等对改性效果的影响.结果表明:湿法改性效果优于干法,KH570的改性效果好于其它两种偶联剂.通过扫描电镜和力学性能测试对经KH570处理过的氧化锌晶须与聚丙烯制成复合材料的界面作用效果进行考查.结果显示:处理后的四针状氧化锌晶须与聚丙烯基体界面作用良好,所制备的复合材料力学性能优于未经处理的四针状氧化锌晶须所制备的材料.     

表面修饰银纳米颗粒的制备及摩擦学性能

以3-氨基-1,2,4-二噻唑-5-硫酮(ADTT)和均苯四甲酸酐为原料,在四氢呋喃溶液中,70℃下酰胺化反应合成了2,5-二(5-硫酮-1,2,4-二噻唑-3-甲酰胺基)-对苯二甲酸(BtdyTA),收率74%。以NaBH4为还原剂,在AgNO3水溶液中用液相化学还原法合成了表面修饰BtdyTA的银纳米颗粒,用透射电子显微镜(TEM)、傅里叶红外转换光谱仪(FTIR)和热分析仪(TG)对纳米颗粒的形貌、结构和热稳定性进行了表征,并在四球摩擦试验机上测试了表面修饰银纳米颗粒的抗摩减磨性能。结果表明,表面修饰的银纳米颗粒粒径分布均匀,平均粒径10nm左右,无团聚现象;在质量分数不大于5%时,可较好分散于液体石蜡等有机溶剂中,作为一种新的基础润滑油添加剂,可使摩擦系数减小32%,最小磨斑直径减小39%。     

无机晶须材料的研究和应用进展

正无机晶须(Whisker)是一种具有一定长径的纤维状晶体,具有优良的力学性能、化学稳定性以及再生性能等,被称为二十一世纪的补强材料,在工程塑料、涂料及隔热、绝缘材料等领域具有广泛的应用,开发利用前景广阔。常见的无机晶须1、氧化锌晶须。氧化锌晶须(ZnOw)按结构形态不同可分为针状晶须和立体四针状晶须。前者与其他针状晶须一样,主要用作复合材料的增强剂;后者因为结构独特,除用于增强外,还可     

纳米氧化锌的制备和表面改性

以七水硫酸锌和碳酸氢钠为主要原料,采用室温固相法结合微波热分解法制备了纳米氧化锌。为改善氧化锌微粒表面的物理化学性质,采用硬脂酸对氧化锌表面进行改性,探讨了硬脂酸改性纳米氧化锌粉体的工艺条件、表面改性机理及其对粉体颗粒亲油性的影响。采用红外光谱对改性后纳米氧化锌进行了表征,结果表明硬脂酸和纳米氧化锌之间以共价键结合,改性后纳米氧化锌能更好地分散在有机溶剂里。纳米氧化锌表面改性的最佳工艺条件:硬脂酸质量分数为10%,改性温度为60℃,改性时间为40 m in。     

银负载氧化锌复合材料的制备及其抗菌性能

以ZnO纳米颗粒为核心,AgNO_3为银源,甲醛为还原剂,采用简单的三步法制备出了银负载氧化锌复合材料。采用扫描电子显微镜(SEM)、X射线能谱仪(EDS)、X-射线衍射仪(XRD)、光致发光光谱(PL)、激光扫描共聚焦显微镜(CLSM)、抑菌圈法、抗生素对比试验、细菌比浊法等分析技术研究了所制备银负载氧化锌复合材料的微观结构及抗菌性能。结果表明,制备出的银负载氧化锌复合材料,ZnO的晶相并未改变,且银均匀的负载在氧化锌表面,负载程度可以通过改变银-三乙醇胺溶液的浓度进行微调;该复合材料对革兰氏菌有很好的抗菌性能,且负载程度越高,产物抗菌性能越大。     

氧化锌晶须渗入聚丙烯腈纤维的抗静电性能

在乳液中悬浮的氧化锌晶须渗入聚丙烯腈纤维中,起到抗静电作用,聚丙烯腈纤维的体积比电阻率可降到4.1×108Ω.cm;四针状和单针状的氧化锌晶须的渗入能力不同,得到抗静电性能不同;渗入工艺简单方便,同时解决了氧化锌晶须添加入聚丙烯腈纺丝原液所造成的喷丝孔阻塞问题。     

SiO2化学沉淀包覆T-ZnOw改性PP

利用沉淀包覆法将乙酸乙酯作为沉淀剂在四针状氧化锌晶须(T-ZnOw)表面均匀包覆SiO2无机层,并对T-ZnOw进一步偶联处理后,用以改性聚丙烯(PP).研究了T-ZnOw对PP力学性能及电性能的影响,结果表明,经过表面包覆的T-ZnOw能够使PP的拉伸屈服应力提高到25.96 MPa,电阻率下降2个数量级.扫描电子显微镜分析表明:经表面包覆的T-ZnOw分散能力大幅度提高.     

骨水泥自固化修饰聚氨酯多孔支架

为了改善有机多孔支架的生物活性,利用磷酸钙骨水泥在潮湿空气中的自固化特性,以α-磷酸钙骨水泥为浆料体系,采用涂覆法对多孔聚氨酯进行表面修饰,获得了表面被羟基磷灰石(Cai0(PO4)6(OH)2,HAp)修饰层包裹的多孔复合材料.结果表明:在α-磷酸钙骨水泥浆料中加入2.5%(质量分数)的聚丙烯酸铵,通过与水化中成核的羟基磷灰石相互作用,改变表面电荷,能有效抑制羟基磷灰石的生长;水化后的修饰层主要由原位生长的纳米HAp晶须和多孔构成,晶须直径约为10～30nm;多孔体结构与模板相似,为贯通式通孔,孔径范围在150～500μm之间.通过自固化修饰技术,在保持原有材料的孔结构基础上,可有效改善其生物活性.     

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。