力化学处理纳米CaCO3/ACR复合粒子对PVC力学性能的影响

通过力化学方法制备了纳米CaCO3／ACR母粒,并研究了其对PVC力学性能的影响;通过SEM方法观察了拉伸试样纵断面裂纹的发展情况和冲击脆断面粒子的分布情况。研究结果表明：纳米CaCO3经过丙烯酸丁酯表面处理后再与ACR共振磨处理能有效地改善纳米CaCO3与聚合物之间的界面粘接,使其界面粘接增强,有利于提高复合体系的力学性能。     

纳米CaCO3对PET／M-POE体系力学性能的影响

采用马来酸酐接枝乙烯-辛烯共聚弹性体(M-POE)和纳米CaCO3协同增韧聚对苯二甲酸乙二酯(PET)。结合复合材料的室温缺口冲击断面扫描电镜照片、淬断刻蚀照片和宏观力学性能,分析了复合体系发生脆-韧转变对应的微观形貌特征。结果表明,直接将M-POE、纳米CaCO3与PET熔融共混并不能起到协同增韧效果,随着纳米CaCO3含量的增加,三元复合体系的缺口冲击强度逐渐降低。纳米CaCO3经过不同表面处理后,在复合体系中的微观分布不同,从而导致体系力学性能变化。不同的加工工艺可以制得纳米CaCO3分布不同的复合材料。研究发现,纳米CaCO3分布于PET基体中会引起复合材料冲击强度的下降。而纳米CaCO3分布于弹性体中,即形成所谓的“沙袋结构”,不仅可以明显提高复合材料的冲击强度,还可降低橡胶用量。     

CaCO3／PVC纳米复合材料的研究

研究了经过表面改性的纳米CaCO3添加量对PVC／米CaCO3复合材料聚合工艺和力学性能的影响。结果表明,纳米CaCO3经过处理后,表面包覆了一薄层的有机物。纳米CaCO3在3％-7％的添加范围内,可以缩短聚合反应时间。纳米PVC与普通PVC比较,冲击强度可提高到9．38kJ／m^2,断裂伸长率在拉伸强度略有降低的前提下增大到60．2％。纳米CaCO3的添加量为7％时,可以得到综合性能较好的纳米CaCO3／PVC复合树脂。     

聚甲醛/纳米CaCO3体系的制备与性能

用纳米CaCO3填充改性聚甲醛(POM)，研究了纳米CaCO3的含量、粒径对POM／纳米CaCO3复合体系力学性能、分散形态等的影响。结果表明，影响复合体系韧性的主导因素是纳米CaCO3在POM中的分散形态及其与POM间的界面粘结状况；纳米粒子在POM中分散均匀，分散相尺寸小，与POM间界面粘结好有利于提高复合体系的冲击韧性；纳米CaCO3的增强增韧作用优于微米CaCO3。     

复合化学镀(Ni-P)-Si3N4纳米微粒复合镀层研究——表面活性剂的影响

采用化学镀方法制备(Ni-P)-Si_3N_4纳米微粒复合镀层,研究了不同类型表面活性剂及分散方式对镀液中纳米粉体分散稳定性的影响。结果表明:采用超声波加阴离子表面活性剂分散纳米粉体,可提高镀液中纳米颗粒的分散和稳定性;提高了镀层的硬度,使复合镀层的耐蚀性比Ni-P合金镀层提高20%～50%,耐磨性提高将近4倍。     

PS/POE/纳米CaCO3复合材料的制备与性能研究

通过熔融共混法制备了PS／POE／纳米CaCO3复合材料。研究了复合材料的力学性能、微观结构和流变性能。结果表明：纳米CaCO3和POE在PS／POE／纳米CaCO3复合体系中互幅促进分布及均化,有协同增韧的作用;同时,纳米CaCO3在PS／POE／纳米CaCO3复合体系中具有提高体系流动性的作用。     

PVC／纳米CaCO3复合材料的研究

研究了表面经硅烷处理的纳米CaCO3填充PVC复合材料的力学性能。结果表明：用量为0.2％的KH-570表面处理过的15份纳米CaCO3对PVC有显著的补强与产韧效果。初步推论了PVC／纳米CaCO3的复合增韧机理.     

纳米碳酸钙在醇相中的表面处理及其原位复合材料制备

在醉相中用具反应活性的甲基丙烯酸(MAA)对纳米碳酸钙(CaCO3)进行表面处理,制成分散体系。研究了MAA用量、pH值、分散时间、温度等对分散体系稳定性及形态的影响。TEM分析表明,在醉相中用10份的MAA对纳米CaCO3粒子进行处理,可以达到较好的分散效果;在原位本体聚合制得的聚苯乙烯(PS)/纳米CaCO3复合材料中,纳米CaCO3粒子能均匀分散,粒径在100 nm以内。纳米CaCO3能较好地增韧增强PS/纳米CaCO3复合材料,含7% -8%,纳米CaCO3的原位复合材料的冲山强度和拉伸强度分别为纯PS的258‘%,和311%,     

纳米级CaCO3填充LDPE复合材料的研究

研究了高分子表面处理剂处理纳米CaCO3填充LDPE复合膜的力学性能。结果表明，由于纳米粒子的表面效应以及高分子表面处理剂的作用，加入少量的纳米粒子，复合体系的拉伸强度、断裂伸长率和直角撕裂强度均有不同程度的增加。     

基体粘度对PA-6／纳米CaCO3复合体系结构与性能的影响

研究了基体粘度对复合体系力学性能、吸水率和尺寸稳定性的影响。采用扫描电镜和透射电镜分析、观察了不同粘度基体的PA-6／纳米CaCO3复合体系冲击断面的微观形态，及纳米CaCO3粒子在不同粘度基体中的分散状况。结果表明，纳米CaCO3粒子在相对粘度较大的PA-6基体中更易分散，分散均匀性提高，冲击断面呈现韧性断面；适量的纳米CaCO3，能提高PA-6／CaCO3复合体系的冲击强度，特别是对粘度较大(R．V．=2．8dL／g)的基体，复合材料的冲击强度提高了40％。而体系的拉伸强度基本不降低。同时，纳米CaCO3的加入，能降低复合体系的吸水率，提高尺寸稳定性，与基体的粘度无关。     

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。