聚吡咯/二氧化硅复合材料的制备及导电性的研究

以三氯化铁(FeCl3)为氧化剂,对甲苯磺酸钠(TSANa)为掺杂剂,在水中使吡咯(Py)单体在二氧化硅(SiO2)粒子表面发生化学氧化聚合反应,制备了具有良好导电性的聚吡咯/二氧化硅(PPy/SiO2)复合材料。结果表明:当FeCl3与Py的摩尔比为2 5,Py与SiO2的质量比为0 3,TSANa的浓度为0 020g·ml-1,在10℃下反应4h,得到的复合材料具有最高电导率12 6S·cm-1。FT-IR结果表明:在形成复合材料过程中PPy与SiO2发生了一定的物理和化学作用。     

聚丙烯/蒙脱土纳米复合材料的制备与性能研究

采用十八烷基三甲基氯化铵（OTAC）和十二烷基二甲基卞基氯化铵（DDBAC）改性蒙脱土,以聚丙烯接枝马来酸酐（PP-g-MAH）作相容剂,通过熔融插层法制备了聚丙烯/蒙脱土纳米复合材料（PP/OMMT）.结果表明,PP-g-MAH能有效地改善PP与OMMT的相容性,当OTAC改性的蒙脱土（OMMT-O）用量为5wt%、PP-g-MAH用量为10wt%时,PP/PP-g-MAH/OMMT-O纳米复合材料的冲击强度为5.4 KJ/m^2,比纯PP提高了80%,极限氧指数（LOI）由PP的18提高到23.X射线衍射（XRD）测试表明,PP已经插层进入到蒙脱土片层中,部分蒙脱土产生了剥离.     

端羟基聚丁二烯/聚氨酯/有机蒙脱土纳米复合材料的制备及性能

以双羟乙基甲基氢化牛脂基氯化铵为插层剂,采用单体插层法制备了端羟基聚丁二烯(HTPB)、聚氨酯(PU)和有机蒙脱土(OMMT)纳米复合材料.当OMMT为3质量份时,HTPB/PU/OMMT纳米复合材料的T型剥离强度是HTPB/PU复合材料的2.58倍.X射线衍射和透射电镜分析表明,OMMT在HTPB/PU/OMMT纳米复合材料中呈剥离状态.     

PBAT/OMMT复合材料的力学性能研究

以可降解聚酯聚对苯二甲酸丁二醇酯-己二酸丁二醇酯(PBAT)、有机蒙脱土(OMMT)为原料,采用熔融插层复合技术制备可降解聚酯(PBAT)/有机蒙脱土纳米复合材料,并对材料的相关性能进行了表征和研究。首先,采用固相插层法以十六烷基三甲基溴化铵(CTAB)为插层剂,对蒙脱土进行有机化处理,并对固相插层工艺进行了详细的研究。结果表明:插层剂用量、搅拌温度,搅拌时间都成为了影响插层效果的因素。然后将有机蒙脱土(OMMT)与PBAT进行熔融插层共混,制得可降解聚酯PBAT/蒙脱土纳米复合材料,并使用X射线衍射(XRD)、拉伸机、差示量热扫描(DSC)对其性能进行表征。考察了蒙脱土含量对复合材料性能的影响。结果表明,熔融插层制备的纳米复合材料的力学性能、热性能等与纯的PBAT相比都有了较大的提高。     

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。     

PB-TPE/OMMT复合材料的结构与性能研究

采用烷基季铵盐类有机插层剂十六烷基三甲基溴化铵（CTAB）对蒙脱土（MMT）进行了改性处理,制备了有机化蒙脱土（OMMT）,并对聚丁烯-1热塑性弹性体（PB-TPE）进行了马来酸酐接枝改性（PB-TPE-g-MAH）。以PB-TPE-g-MAH为相容剂,通过熔融插层法制备了PB-TPE-g-MAH/OM-MT纳米复合材料。采用傅立叶变换红外光谱（FTIR）、X-衍射（XRD）、透射电镜（TEM）等手段分析了材料结构。结果表明：OMMT在PB-TPE-g-MAH体系中得到了插层和部分剥离,使有机蒙脱土片层间距由原来的1.96 nm增加到3.81 nm。与不含蒙脱土的PB-TPE相比,PB-TPE-g-MAH/OMMT纳米复合材料的拉伸性能得到明显提高。     

母料法制备尼龙6/蒙脱土纳米复合材料及其性能

以高流动性聚丙烯接枝马来酸酐(PP-g-MAH)为载体树脂,制备了接枝聚丙烯/有机蒙脱土插层母料,并以此为增强剂制备了PA6/接枝聚丙烯/有机蒙脱土纳米复合材料,研究了有机蒙脱土(OMMT)含量对复合体系力学性能和耐热性能的影响。通过X射线衍射(XRD)、透射电子显微镜(TEM)研究了复合材料的微观结构。结果表明:在所制备的插层母料中,PP-g-MAH大分子能够部分插入OMMT的晶片层间,其层间距有所增大。母料法制备的PA6/接枝聚丙烯/有机蒙脱土纳米复合材料的力学性能得到了较大提高,当OMMT含量为6%时,拉伸强度和弯曲强度分别比PA6/PP-g-MAH共混体系提高了24%和25.1%。     

硅烷偶联剂复合改性蒙脱土制备NR/OMMT纳米复合材料

采用硅烷偶联剂和十六烷基三甲基溴化铵(CTAB)作为复合改性剂制备有机蒙脱土,使有机蒙脱土的结构发生了改变.其中采用硅烷偶联剂KH570与CTAB复合改性的效果较好,得到了插层效果较好的NR/OMMT纳米复合材料.     

环氧树脂/有机蒙脱土复合材料的制备与力学性能研究

利用插层聚合法制备了环氧树脂/有机蒙脱土(EP/OMMT)复合材料.采用XRD对复合材料进行了表征,并研究了复合材料力学性能.实验表明:环氧树脂/有机蒙脱土形成了剥离型的纳米复合材料结构;环氧树脂中加入适量的有机蒙脱土,可以提高环氧树脂的拉伸强度和冲击强度.当经过改性的OMMT质量分数为5%时,EP/钛酸酯偶联剂(Coupler)-OMMT复合材料的拉伸强度达到51.21 MPa,提高了40.26%;当OMMT质量分数为3%时,EP/Coupler-OMMT复合材料冲击强度达25.31 kJ/m2,提高了34.56%.     

硅烷偶联剂对OMMT/NR纳米复合材料结构与性能的影响

采用混炼插层法制备有机蒙脱土(OMMT)/NR纳米复合材料,研究硅烷偶联剂对其结构和性能的影响.结果表明,与NR相比,OMMT/NR纳米复合材料的物理性能,热稳定性和动态力学性能均有所提高;采用硅烷偶联剂KH-560改性的OMMT制备的纳米复合材料各项性能均优于采用硅烷偶联剂KH-550改性的OMMT制备的纳米复合材料.     

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。