有机插层剂对聚酰胺6／MMT纳米复合材料制备的影响研究

以烷基胺、季铵盐和氨基酸作为有机插层剂与蒙脱土片层进行阳离子交换，制备出层间距不同的有机蒙脱土。采用熔融插层法和原位聚合法分别制备聚酰胺（R％）／蒙脱土（MMT）纳米复合材料，并利用XRD、FT-IR、TEM对有机蒙脱土及纳米复合材料进行结构表征。研究结果表明：用烷基胺、季铵盐和氨基酸有机插层剂改性的蒙脱土层间距由原来的1．25nm分别增大到3．21nm、3．99nm和1．82m；季铵盐有机插层剂更适用于熔融插层法制备PA6／MMT纳米复合材料，而氨基酸有机插层剂更适用于原位聚合法制备PA6／MMT纳米复合材料。     

聚对苯二甲酸丁二醇酯/聚甲基丙烯酸甲酯季铵盐修饰蒙脱土纳米复合材料的制备与性能

用聚甲基丙烯酸甲酯苄基季铵盐和聚甲基丙烯酸甲酯十八烷基季铵盐修饰蒙脱土,制备出两种有机土（MAPS-B-MMT和MAPS-O-MMT）,通过熔融共混法制备聚对苯二甲酸丁二醇酯/蒙脱土（PBT/MMT）纳米复合材料,考察了有机土含量和修饰剂结构对复合材料性能的影响。TEM结果显示,两类复合材料均为插层型纳米复合材料。热稳定性能研究表明,PBT/MAPS-B和PBT/MAPS-O两个体系热稳定性有较大的改善,材料的初始降解温度均比纯PBT提高,PBT/MAPS-O-2纳米复合材料的初始降解温度提高了20 ℃;热稳定性受到蒙脱土分散性影响,随着黏土含量增加,蒙脱土分散性变差,导致材料初始降解温度下降,质量分数2%为蒙脱土的最佳含量;加入有机土降低了材料的熔融温度,提高了材料的结晶速率和结晶度。     

聚氯乙烯/蒙脱土纳米复合材料的研究

采用熔融插层法制备了聚氯乙烯(PVC) /蒙脱土(MMT)纳米复合材料并进行了表征,研究了PVC/MMT纳米复合材料的力学性能。结果表明:PVC进入到有机MMT的片层间形成了纳米复合材料,但PVC不能进入钠基MMT的片层间,形成纳米复合材料;蒙脱土的加入提高了PVC的力学性能,而且PVC/有机MMT纳米复合材料的拉伸和冲击强度总是优于PVC/钠基MMT复合材料;对PVC/有机MMT纳米复合材料而言,复合材料的V型缺口冲击比U型缺口冲击敏感,其力学性能随热处理时间延长而降低,但PVC/有机MMT复合材料比PVC/钠基MMT的抗热性好。     

PTT/MMT纳米复合材料的制备及性能的研究

采用熔融共混的方法制备了聚对苯二甲酸丙二醇蘸/蒙脱土(PTT/MMT)纳米复合材料,并用红外光谱表征了PTT/MMT纳米复合材料的结构.通过DSC、热台偏光显微镜等研究了PTT/MMT纳米复合材料的结晶行为,测定了纳米复合材料的力学性能.结果表明,随着PTT/MMT纳米复合材料中蒙脱土含量的增加,PTT/MMT纳米复合材料的熔融结晶温度增高.其结晶过程为异相成核,纳米复合材料的力学性能有一定的提高.     

聚丙烯/蒙脱土纳米复合材料的制备和性能

采用熔融插层法在双螺杆挤出机中制备了聚丙烯(PP)/蒙脱土(MMT)纳米复合材料,纳米复合材料机械性能测试结果表明,当有机MMT质量分数为2%时,复合材料的弯曲强度明显优于PP。扫描电镜观测不到纳米复合材料中明显的有机-无机相畴,表明MMT片层分散均匀,分散尺度已基本达到纳米级。DSC(差示扫描量热仪)分析测试结果表明,MMT的加入提高了PP的结晶速率,并使结晶度增大。     

PET/MMT纳米复合材料的制备

采用烷基季铵盐对蒙脱土(MMT)进行有机化处理,采用插层聚合法制备PET/MMT纳米复合材料。探讨了不同的MMT来源、添加量及聚合条件对PET/MMT纳米复合材料耐热性能的影响。结果表明: MMT的添加质量分数为2.5%,缩聚反应终温250℃时,PET/MMT纳米复合材料具有较好的综合性能。     

PTT/MMT纳米复合材料的研究

采用熔融共混的方法制备了聚对苯二甲酸丙二醇酯/有机蒙脱土（PTT/MMT）纳米复合材料,通过DSC、热台偏光显微镜等研究了PTT/MMT纳米复合材料的结晶行为,测定了纳米复合材料的力学性能,并用熔体流变仪研究了PTT/MMT纳米复合材料熔体流变性能。结果表明：随着PTT/MMT纳米复合材料中蒙脱上含量的增加,PTT/MMT纳米复合材料的熔融结晶温度增高,纳米复合材料的力学性能有一定的提高;PTT-蒙脱土纳米复合材料熔体的流变性能随MMT含量的增加非牛顿性减弱,熔体的粘流活化能减小。     

含氮相容剂对聚丙烯/蒙脱土复合材料阻燃性能的影响

以N-羟甲基丙烯酰胺接枝聚丙烯(PP-g-NHA)为相容剂,采用熔融插层法,制备聚丙烯(PP)/蒙脱土(MMT)纳米复合材料;采用X射线衍射仪(XRD)、偏光显微镜(POM)、差式扫描量热仪(DSC)和氧指数仪(LOI)等对复合材料的微观结构和性能进行了研究。结果表明PP-g-NHA能有效地改善PP与MMT的相容性,当蒙脱土用量为5%、PP-g-NHA用量为15%时,PP/PP-g-NHA/MMT纳米复合材料的极限氧指数(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,当蒙脱土用量为5%、PP-g-NHA用量为5%时插层效果最好,DSC分析结果表明,复合材料的熔融温度和分解温度都有所上升。     

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。     

聚消旋乳酸/蒙脱土纳米复合材料热稳定性的研究

通过熔融混合制得了聚消旋乳酸(PDLLA)／蒙脱土(MMT)纳米复合材料。研究了蒙脱土的加入量对其结构和热稳定性能的影响,结果表明,聚消旋乳酸的分子链已经插入到蒙脱土片层的层间隙中形成了嵌入式的插层结构。蒙脱土的加入使PDLLA／MMT纳米复合材料的玻璃化转变温度增加,其热稳定性明显改善。与纯PDLLA相比,它的起始热分解温度至少提高了22．5℃。蒙脱土的最佳加入量为5％,其断裂伸长率可提高近一倍。     

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。