无机盐(SDS和CaCl2)用量对天然橡胶生胶性能的研究

用无机盐(SDS和Ca Cl2)作为胶乳凝固剂,通过改变用量讨论不同用量对天然橡胶性能的影响。结果表明,当无机盐(SDS和Ca Cl2)分别为干胶含量的0.05%在力学性能方面最好;当无机盐(SDS和Ca Cl2)分别为干胶含量的0.2%硫化特性和热分析优于酸对照样;无机盐含量对无机盐凝固胶理化性能、分子量及分子量分布的差异不显著。     

DK膜对无机盐截留性能的研究

采用Desal-DK有机纳滤膜分别对1²00 mol/m3的Na Cl、KCl、K2SO4、Na2SO4、Mg Cl2和Ca Cl2水溶液进行纳滤实验,考察无机盐的类型、浓度和渗透流率对截留率的影响,结合道南细孔-介电DSPM-DE模型计算等效荷电密度(Xd),采用DSPM模型计算等效膜孔半径(rp),研究不同类型无机盐截留率和Xd的关系。结果表明,KCl和Na Cl溶液随着浓度的升高截留率逐渐降低,并趋近于某一定值,在低浓度时主要因为静电屏蔽的作用,在高浓度时主要因为空间位阻作用;Ca Cl2和Mg Cl2溶液随浓度增加截留率先升高后降低,在某一位置取的截留率最大值,主要因为Mg2+/Ca2+和Cl-交替吸附引起静电作用的变化;Na2SO4和K2SO4溶液截留率随着浓度增加而降低,主要因为静电屏蔽作用增强,排斥力降低;渗透流率的变化可以改变截留率的大小,但对荷电密度几乎没有影响,因此不会改变截留率随浓度变化的趋势,荷电密度对溶液浓度有较强的依赖关系;在研究的盐浓度范围内,DK膜膜孔并没有出现增大的现象,因此溶液截留率的变化和膜孔径无明显关系。     

SEBS/蒙脱土复合材料结构及热性能研究

采用十二烷基三苯基溴化膦(DTPB)改性钠基蒙脱土(Na+-MMT),利用熔融插层法制备氢化苯乙烯-丁二烯-苯乙烯嵌段共聚物(SEBS)/蒙脱土复合材料。采用X射线衍射仪、红外光谱仪、场发射扫描电镜、热重分析仪对样品进行结构表征和性能测试,比较不同有机化蒙脱土(OMMT)对SEBS/OMMT复合材料的影响。结果表明:无论是MMT还是OMMT都起到了阻止SEBS热失重进程的发展,且携带苯基的DTPB有机改性剂有利于OMMT与SEBS复合材料的相容性。     

DK膜对无机盐截留性能的研究

采用Desal-DK有机纳滤膜分别对1~200 mol/m3的Na Cl、KCl、K2SO4、Na2SO4、Mg Cl2和Ca Cl2水溶液进行纳滤实验,考察无机盐的类型、浓度和渗透流率对截留率的影响,结合道南细孔-介电DSPM-DE模型计算等效荷电密度(Xd),采用DSPM模型计算等效膜孔半径(rp),研究不同类型无机盐截留率和Xd的关系。结果表明,KCl和Na Cl溶液随着浓度的升高截留率逐渐降低,并趋近于某一定值,在低浓度时主要因为静电屏蔽的作用,在高浓度时主要因为空间位阻作用;Ca Cl2和Mg Cl2溶液随浓度增加截留率先升高后降低,在某一位置取的截留率最大值,主要因为Mg2+/Ca2+和Cl-交替吸附引起静电作用的变化;Na2SO4和K2SO4溶液截留率随着浓度增加而降低,主要因为静电屏蔽作用增强,排斥力降低;渗透流率的变化可以改变截留率的大小,但对荷电密度几乎没有影响,因此不会改变截留率随浓度变化的趋势,荷电密度对溶液浓度有较强的依赖关系;在研究的盐浓度范围内,DK膜膜孔并没有出现增大的现象,因此溶液截留率的变化和膜孔径无明显关系。     

蒙脱土/EPDM纳米复合材料燃烧性能的研究

采用熔融插层法制备了蒙脱土/EPDM纳米复合材料,并研究了燃烧性能。结果表明,EPDM大分子不能与未有机化的钠基蒙脱土(Na+-MMT)插层复合,但能有效插入有机蒙脱土(OMMT)片层之间,形成OMMT/EPDM插层纳米复合材料。Na+-MMT对改善蒙脱土/EPDM纳米复合材料的阻燃和抑烟效果不明显;OMMT/EPDM纳米复合材料的热释放速率、总生烟量及烟密度等参数均明显降低;随OMMT用量的增大,阻燃性和抑烟性变得越来越好,最后趋于稳定。     

四种纳滤膜对高盐废水分盐效果分析

为了使煤化工零排放高盐废水分盐产出高质量NaCl和Na2SO4结晶盐,提高废水处理过程的分盐效率,以宁东某煤化工零排放高盐废水的水质情况模拟配制了无机盐溶液,选取了膜1、膜2、膜3和膜4等4种商用纳滤膜,探讨了其对模拟高盐废水中的常规离子(Mg2+、Ca2+、Na+、K+、SO42-、Cl-、NO3-)的截留率,并考察...     

咪唑类离子液体对水基钻井液抑制性的影响及机理

油气钻井过程中泥页岩不稳定主要是由于泥页岩的水化作用造成。本文采用页岩滚动回收率法、毛细管吸入时间法和粒度分析法3种方法,与传统抑制剂KCl和新型抑制剂聚胺作对比,评价了离子液体RIL作为抑制剂对水基钻井液抑制性能的影响。结果表明高温作用下低浓度(质量分数0.05%)的离子液体RIL有着优异的抑制黏土膨胀和分散的能力,其抑制效果优于5%KCl,与2%聚胺相当;同时低浓度的离子液体RIL可以改善水基钻井液的高温流变性而不会使钻井液的滤失性变差。通过接触角和热稳定性测试分析了其抑制机理。离子液体RIL改性后的Na蒙脱土润湿性从亲水性向疏水性转变,可以阻止水分子进入Na蒙脱土的层间结构从而抑制Na蒙脱土的膨胀和分散。低浓度的离子液体RIL改性后的钠蒙脱土具有更好的热稳定性,可以提高高温作用下水基钻井液的抑制性。     

蒙脱土负载三氯化铁氧化苯偶姻制备苯偶酰

以酸处理蒙脱土K10为载体,采用浸渍法制备出环境友好的蒙脱土负载FeCl3催化氧化剂,利用红外光谱对其进行了表征。研究了FeCl3的负载量和活化温度对氧化反应的影响。并分别以蒙脱土K10,SiO2,Al2O3为载体制成三氯化铁负载试剂氧化剂,比较了不同载体对催化氧化反应活性的影响。结果表明,蒙脱土K10为本反应的良好载体。以蒙脱土K10负载三氯化铁为催化剂,氧化苯偶姻制备苯偶酰,具有操作简便、反应产物易于分离、氧化剂选择性高等优点。当氧化剂与苯偶姻摩尔配比为1∶1时,在回流温度下氧化反应4 h,苯偶酰的产率为91.8%,其结构经熔点测定和红外光谱表征。     

尼龙11/蒙脱土纳米复合材料形态和性能研究

通过熔融共混法成功地制备了不同含量蒙脱土的尼龙11/蒙脱土纳米复合材料,利用X衍射(XRD)和透射电镜(TEM)研究了尼龙11/蒙脱土纳米复合材料的微观结构。结果表明,当蒙脱土质量分数小于2%时,形成了剥离型的纳米复合材料,当蒙脱土质量分数超过2%时形成了插层型的纳米复合材料。热重分析表明当蒙脱土质量分数为2%时,纳米复合材料的热分解温度比纯尼龙11提高了27℃。不同蒙脱土含量的纳米复合材料悬臂梁冲击强度均比纯尼龙11的高,但其拉伸强度在蒙脱土质量分数小于8%时降低,以后随蒙脱土含量的增加而提高。     

Sb_4O_5Cl_2柱撑蒙脱土复合阻燃剂的制备及表征

以Sb4O5Cl2纳米粒子为柱化剂,采用酸溶法和醇盐水解法制备了Sb4O5Cl2柱撑蒙脱土复合阻燃剂,并用FI-IR、XRD和TEM对产品进行了表征.结果表明酸溶法要优于醇盐水解法,柱撑后蒙脱土的间距扩大,呈弱晶态,蒙脱土和Sb4O5Cl2纳米粒子结合完美,成本低廉,可作为一种有效的添加型阻燃剂.     

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。