原位聚合制备尼龙610/改性蒙脱土纳米复合材料的研究

采用增塑剂N-甲基苯磺酰胺对蒙脱土(MMT)进行改性,通过原位聚合法制备了尼龙(PA)610/改性MMT纳米复合材料。研究了改性MMT用量对PA610/改性MMT纳米复合材料性能的影响。结果表明,当改性MMT的质量分数为4%时,纳米复合材料的冲击强度和拉伸强度达到最大值,断裂伸长率则随着改性MMT用量的增加而降低。扫描电子显微镜观察发现,改性MMT均匀分散在PA610基体中。     

PUA/MMT复合材料的制备与研究

采用硝酸锌、烯丙基三苯基溴化磷(APB)为插层剂对蒙脱土(MMT)进行无机-有机复合改性,实现对MMT的改性.利用改性后的MMT制备了丙烯酸酯类聚氨酯(PUA)/MMT复合材料.研究了PUA/MMT复合材料的结构和性能.结果表明,改性MMT加入后,PUA/MMT复合材料的热稳定性和玻璃化转变温度得到提高,但拉伸强度随着改性MMT含量的增加先升高后降低.以金黄色葡萄球菌为研究对象对改性MMT和PUA/MMT复合材料进行抗菌定性测试,结果表明,PUA/MMT复合材料的抗菌性能不明显,但改性MMT具有较好的抗菌性能.     

聚乙烯醇/改性纳米蒙脱土复合材料的制备与性能

纳米蒙脱土(MMT)用十六烷基三甲基溴化铵进行改性制得有机改性的MMT(OMMT),用其作为聚乙烯醇(PVAL)的改性材料,采用溶液共混、流涎成膜制得PLA/OMMT复合材料,考察了OMMT的用量对PVAL复合材料性能的影响。用傅立叶变换红外光谱(FTIR)仪、差示扫描量热仪、扫描电子显微镜、X射线衍射仪、万能力学试验机等对复合材料性能及结构进行表征和分析。结果表明,FTIR显示十六烷基三甲基溴化铵成功进入MMT结构中,OMMT成功制得;随着OMMT添加量的增加,复合材料热稳定性提高,断裂伸长率降低,拉伸强度呈现先增加后降低趋势,当其含量为9%时达到最大;SEM显示OMMT含量9%时,OMMT与PVAL相容性最好,表面光滑,含量再增加,出现团聚现象,力学性能受到影响。     

NBR／PP／蒙脱土纳米复合体系的制备和性能研究

以丙烯酸接枝聚丙烯为增容剂,采用熔融复合方法制备出NBR/PP/蒙脱土纳米复合体系。对丙烯酸熔触接枝PP的增容体系进行了深入得研究,其次还对未处理的MMT和处理过的纳米MMT对共混物结构和性能得影响进行了讨论。研究表明,在使用丙烯酸接枝PP对NBR/PP体系得增容性较好,通过熔融共混得方法制备了NBR/PP/蒙脱土纳米复合材料。对复合材料的介电性能,力学性能和相容性进行了研究,用红外光谱和扫描电镜表征该复合材料的结构。结果表明:丙烯酸接枝聚丙烯能够很好的改善PP和NBR、MMT的相容性,当十六烷基三甲基溴化铵(CTAB)改性的蒙脱土用量为5Wt%、PP-g-AA用量为10Wt%时,NBR/PP/蒙脱土纳米复合材料的断裂伸长率提高20%,拉伸强度提高10%,撕裂强度提高80%。     

PP/MMT复合材料的制备与性能研究

以聚丙烯(PP)回收料为基体,改性蒙脱土(MMT)为填充剂,通过熔融共混的方法制备了PP/MMT复合材料,探讨了MMT用量对PP/MMT复合材料的热行为、机械性能及流动性能的影响。结果表明:少量MMT的加入可明显提高复合材料的力学性能,其拉伸强度提高26%,断裂伸长率提高520%,冲击强度提高11%。MMT的加入可提高复合材料的结晶温度,但对其熔点的影响不大;随着MMT的添加,PP/MMT复合材料的流动性能得到了很好的改善,当MMT的含量为1 wt%时,其熔融指数达到最大值,体系的粘度变小。     

纳米CaCO3填充PTFE复合材料力学性能的研究

通过机械搅拌、冷压成型烧结方法,制备了纳米碳酸钙填充改性聚四氟乙烯(PTFE)复合材料;并研究了复合材料的物理机械性能。结果表明未改性的纳米碳酸钙显著提高了复合材料的弹性模量、断裂伸长率和冲击强度,其中断裂伸长率最高可达800%,冲击强度亦可提高到纯PTFE的233%;但复合材料的拉伸强度有所降低。改性后的纳米碳酸钙效果并不是很理想,主要是表面改性剂高温分解存在的影响。     

氧化铝/环氧树脂/聚氨酯导热复合材料的制备及表征

采用硅烷偶联剂KH550对氧化铝表面进行改性,并以改性氧化铝为导热填料,以环氧树脂为基体树脂,自制的聚氨酯预聚体为柔性改性剂,制备了氧化铝/环氧树脂/聚氨酯导热复合材料。采用红外光谱对KH550改性氧化铝的结构进行了表征,探讨了影响复合材料热导率的主要因素,研究了改性氧化铝用量对复合材料力学性能的影响,并利用扫描电镜对复合材料的微观结构进行了观察。结果表明,KH550已通过化学键接枝在氧化铝表面。随着KH550改性氧化铝用量的增加,复合材料的拉伸强度逐渐增大,而导热率和断裂伸长率呈现先上升后下降的趋势。当改性氧化铝的用量为150 phr时,复合材料的导热率达到最大值0.66 W/(m·K),拉伸强度和断裂伸长率分别为37.2 MPa和1.62%。随着m(PUA)/m(EP)的增大,复合材料的导热率相应下降,适宜的m(PUA)/m(EP)为15/85。     

不同改性蒙脱土对ENR/PVC共混型TPV填充效果的研究

采用熔融插层法制备了聚氯乙烯/蒙脱土(PVC/MMT)插层产物,再将该产物与环氧化天然橡胶(ENR)在密炼机中进行熔融共混制备ENR/PVC/MMT共混型热塑性弹性体(TPV),研究了不同改性MMT对共混物力学性能、热稳定性以及动态力学性能的影响。结果表明:二甲基双十八烷基铵改性蒙脱土(MMT-2C18)能显著提高ENR/PVC共混型TPV的拉伸强度,无机MMT能显著提高ENR/PVC的断裂伸长率,十八烷基铵改性蒙脱土(MMT-C18)会降低TPV的拉伸强度和断裂伸长率;有机改性MMT会促进TPV中PVC的降解,使得复合材料的热稳定性降低;动态热力学分析显示,MMT可使复合材料的储能模量增加,其中有机改性MMT使材料的损耗因数(tanδ)曲线峰强降低,峰宽变宽。     

PLA/改性MMT复合材料的性能

以十六烷基三甲基溴化铵(CTAB)为改性剂对蒙脱土(MMT)进行改性,将其填充到聚乳酸(PLA)中,采用熔融插层法制备了PLA/改性MMT复合材料,并研究了复合材料的性能。结果表明:添加MMT可提高复合材料的阻燃性能和耐热性能;添加未改性MMT降低了复合材料的力学性能,当其用量为9 phr时,复合材料的拉伸强度从42.1 MPa降至38.6 MPa,断裂拉伸应变从4.5%降至2.2%,冲击强度从15.2 kJ/m~2降至8.6 kJ/m~2;添加适量(3~5 phr)改性MMT可提高复合材料的力学性能,当其用量为5 phr时,复合材料的拉伸强度和断裂拉伸应变均达最大值,分别为47.2 MPa和10.6%,当其用量为3 phr时,复合材料的冲击强度达最大值,为25.2 kJ/m~2。     

纳米纤维素-竹粉改性环氧树脂复合材料研究

以采用溶剂交换和熔融机械搅拌相结合的方法制备了纳米纤维素-竹粉改性的环氧树脂复合材料。采用拉伸性能测试、示差扫描量热仪(DSC)研究了复合材料的力学性能及固化反应。结果表明:随着竹粉含量增加,竹粉改性环氧体系的拉伸强度及拉伸弹性模量呈上升趋势,但断裂伸长率明显降低。而竹粉与纳米纤维素协同改性的环氧体系不仅改善了断裂伸长率而且在原来基础上再次提升了拉伸强度及拉伸模量。与纯的环氧基体相比,添加纳米纤维素质量分数为0.2%及竹粉质量分数为20%的体系性能最佳。竹粉的加入对环氧树脂固化反应有一定的阻碍作用,而纳米纤维素对反应有一定的促进作用。     

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。