PP-g-MAH对PP/纳米SiO_2复合材料性能的影响

采用熔融共混法制备了聚丙烯(PP)/纳米SiO2复合材料,研究了相容剂马来酸酐接枝聚丙烯(PP-g-MAH)对复合材料力学性能、结晶性能及界面作用的影响。结果表明:PP-g-MAH能有效地增强纳米SiO2与PP基体间的界面作用,提高复合材料的力学性能;同时,PP-g-MAH增强了纳米SiO2的成核活性,使PP的结晶温度升高,球晶细化。     

新型纳米光触媒剂二氧化钛改性聚丙烯的研究

采用一种新型的纳米光触媒剂二氧化钛(TiO2)来改性聚丙烯(PP)，将无机纳米粒子通过熔融共混方法与PP复合制备了纳米TiO2／PP复合材料，利用透射电子显微镜(TEM)观察纳米粒子在聚丙烯基体中的分散效果，研究了纳米TiO2／PP复合材料的力学性能和抗菌性能。实验结果表明，填充量较少时纳米TiO2在PP基体中能够实现良好的分散。力学性能测试结果表明，填加质量分数为1％的纳米TiO2可以明显提高PP材料的抗冲击性能；纳米粒子质量分数在0～1％范围内对复合材料的拉伸强度几乎没有影响；而随着纳米光触媒剂TiO2的加入，PP具有良好的杀菌作用，并且随着TiO2含量的增加，复合材料的抗菌性能呈明显提高趋势。     

无机纳米填料改性聚丙烯的研究进展

综述了聚丙烯/无机纳米复合材料的制备、填料表面处理、物理力学性能。可用大分子相容剂或官能化聚丙烯,改善PP纳米材料的分散性、界面黏结和力学性能。研究表明:少量无机纳米粒子可增强增韧PP。     

纳米SiO2增韧聚丙烯（PP）的研究

通过熔融共混法制备了聚丙烯（PP）／SiO2纳米复合材料，并使用扫描电镜（SEM），电子拉力机和冲击机等对材料进行表征。研究发现硅烷偶联剂对纳米SiO2在聚丙烯（PP）中的分散起一定的作用，但不是非常有效。添加相容剂PP-g-MAH后，可以使纳米SiO2均匀地分散于PP中。当纳米SiO2含量为2重量份时，PP/SiO2纳米复合材料的性能最优，与纯PP相比较，Izod冲击强度提高了90％，拉伸强度略微提高了5％，弯曲强度提高了23%。最后，作者对纳米SiO2的增韧机理和PP-g-MAH大幅度改善纳米SiO2在PP中分散效果的机理作了初步推断。     

无机纳米材料改性聚丙烯的研究进展

本文综述了聚丙烯／无机物纳米复合材料的制备、表面处理、物理与力学性能的研究进展。PP纳米复合材料可用传统的方法成型加工，除用传统的偶联剂外，可用大分子相容剂或官能团化聚丙烯作为偶联剂或基体，改善PP纳米材料的分散性、界面粘结和力学性能。少量无机物纳米粒子可使PP获得增强增韧。     

PMA表面接枝包覆纳米TiO2及其在PP中抗紫外老化的研究

以硅烷偶联剂对纳米TiO2进行表面预处理，在此基础上以聚甲基丙烯酸（PMA）对其表面接枝包覆，后以马来酸酐接枝聚丙烯（PP-g-MAH）为载体，通过母料复合工艺制备了PP纳米复合材料。分析了处理后纳米TiO2的结构并对其在PP中的分散情况及抗紫外老化性能进行了比较。结果表明：PMA在纳米TiO2表面接枝率约为50％；与未处理TiO2及硅烷处理样品相比，PMA接枝包覆使纳米TiO2在PP中的分散均匀性及抗紫外老化性能均获得了改进。     

纳米TiO2的表面处理及聚丙烯／TiO2复合体系的研究

通过多种方法对纳米TiO2粒子进行了表面处理，深入探讨了纳米粒子的分散机理。制备了PP／TiO2复合材料，对此复合材料进行了力学性能测试和结构表征，讨论了分散度和复合材料性能的关系。结果表明：通过熔融共混法可以将经适当表面处理的纳米TiO2粒子均匀地分散在聚丙烯中，纳米TiO2粒子在4％用量时可以使聚丙烯的缺口冲击强度提高1倍，同时其拉伸强度也有很大提高。     

相容剂对碳纤维增强聚丙烯复合材料性能的影响

研究了马来酸酐接枝聚丙烯(PP-g-MAH)和甲基丙烯酸缩水甘油酯接枝聚丙烯(PP-g-GMA)2种相容剂对碳纤维增强聚丙烯(CF/PP)复合材料性能的影响。结果表明:随着相容剂添加量的增加,CF/PP复合材料的拉伸强度、弯曲强度、缺口冲击强度增加,相容剂添加质量分数在6%时增加效果最为明显;2种相容剂对熔融温度及结晶度影响不大,但PP-g-MAH对CF/PP复合材料综合性能的提升优于PP-g-GMA。     

树状大分子PAMAM改性凹凸棒石填充改性聚丙烯研究

采用聚酰胺-胺(PAMAM)树枝状大分子对硅烷偶联剂处理过的凹凸棒石(ATP)进行接枝改性,制得改性粒子ATP-PAMAM.通过热重-差热分析(TG/DTA)和红外光谱(FIIR)表征了PAMAM在ATP表面的接枝效果.以该ATP-PAMAM为分散相,PP-g-MAH为相容剂与聚丙烯(PP)基体熔融共混制备了PP/ATP-PAMAM复合材料.结果表明:用ATP-PAMAM制得的复合材料比用未处理的ATP制得的复合材料具有更好的综合力学性能;ATP-PAMAM呈纳米棒状均匀分散在PP基体中,通过与PP-g-MAH发生化学反应,提高了与PP的相容性,与基体结合良好;具有异相成核作用,使PP的结晶度有较大提高.     

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.     

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。