碳酸钙／聚丙烯复合材料的力学性能对比研究

研究了无机刚性材料纳米或微米碳酸钙对聚丙烯(PP)的填充改性以及利用钛酸酯偶联剂对纳米碳酸钙进行表面处理后,对于碳酸钙/聚丙烯复合材料体系的力学性能的影响.结果表明,纳米碳酸钙/聚丙烯复合材料的力学性能明显优于微米碳酸钙/聚丙烯复合材料的力学性能;钛酸酯偶联剂改性处理纳米碳酸钙粒子后,其复合体系的冲击强度和断裂伸长率有明显的提高.     

改性纳米氧化锌对丙烯酸聚氨酯涂层防腐性能的影响

为了改善纳米ZnO在涂料中的分散性,以钛酸酯偶联剂对其进行改性。研究了丙烯酸聚氨酯清漆、含未改性纳米氧化锌的丙烯酸聚氨酯涂层和添加钛酸酯偶联剂改性后的纳米氧化锌的丙烯酸聚氨酯涂层的防腐蚀性能。结果表明,经过钛酸酯偶联剂改性的纳米ZnO其团聚现象明显消失,与涂料表现出良好的相容性,所得的复合涂层的抗渗透能力明显比清漆和含未改性纳米ZnO复合涂层强。改性纳米ZnO显著提高了丙烯酸聚氨酯涂料的防腐性能。     

纳米TiO_2的表面改性研究

用钛酸酯偶联剂JSC对纳米TiO2进行表面处理,研究了钛酸酯偶联剂用量、反应温度、反应时间等对纳米TiO2表面改性效果的影响。红外光谱分析结果表明,纳米TiO2表面化学键合有钛酸酯偶联剂的有机官能团,导致其表面极性有所减弱。SEM观察表明,表面改性后纳米TiO2的团聚程度降低,微粒直径大多在20nm左右,偶联反应对原粉末晶型不会产生影响。     

硅烷偶联纳米SiO2改性形状记忆聚氨酯

本文采用经硅烷偶联剂表面处理的纳米SiO2粒子制备了形状记忆聚氨酯／SiO2纳米复合材料。并用SEM、DSC、TGA对其进行分析,考察其形状记忆行为及力学性能。结果表明,形状记忆聚氨酯中加入纳米SiO2后,其热稳定性能提高了,形状回复起始温度(Ti)提高约10℃,形状回复速率提高约3．8倍,而力学性能有所下降。     

β-SiCw/赛璐珞纳米复合材料的制备与研究

用钛酸酯偶联剂对纳米β-碳化硅晶须（β-SiCw）进行表面处理．并采用共混法制备了纳米β-SiCw／赛璐珞复合材料。探讨了纳米β-SiCw用量和钛酸酯用量对复合材料力学性能的影响。结果表明,纳米β-SiCw／赛璐珞复合材料的拉伸、弯曲和冲击强度均随纳米β-SiCw用量的增加而明显提高,在β-SiCw用量为5％时,复合材料综合性能最好;当纳米β-SiCw用量一定时,复合材料的力学性能与钛酸酯的用量有关。分析表明,钛酸酯以化学键合的方式结合在纳米β-SiCw表面,并形成了有机包覆层。     

正交设计在改性纳米CaCO3/PVC复合体系中的应用

选择不同的方法对纳米CaCO3进行表面改性,研究了表面处理剂对CaCO3/PVC纳米复合材料界面结合强度、力学性能及加工性能的影响。通过正交实验设计得到了力学性能最佳时的制备条件:表面处理剂选用钛酸酯偶联剂,其用量4%(质量分数),纳米CaCO3用量15%(质量分数)。极差分析结果表明,对冲击强度而言,主要影响因素为表面处理剂用量;扫描电镜显示,钛酸酯偶联剂处理可使纳米CaCO3颗粒在PVC基体中达到良好分散,并提高其界面结合强度;流变性能研究表明,经钛酸酯处理的纳米CaCO3填充PVC具有更低的平衡转矩。     

钛酸酯偶联剂改性纳米氧化锌的研究

采用钛酸酯偶联剂对纳米氧化锌进行表面改性，研究钛酸酯偶联剂和异丙醇用量以及改性条件对改性效果的影响。试验结果表明，钛酸酯偶联剂／纳米氧化锌质量比为0．03、异丙醇用量为40．76mL、反应温度为30℃、反应时间为90min时，活化指数达到99．04％；透射电子显微镜观察发现，改性纳米氧化锌的分散性较好。     

钛酸酯偶联剂改性纳米MgO的研究

以钛酸酯偶联剂为改性剂,采用超声波分散的方法对纳米氧化镁（MgO）进行了表面改性。研究了偶联剂用量、改性温度、改性时间对纳米MgO表面改性的影响。通过活化指数实验和扫描电镜的方法表征了纳米MgO的改性效果。结果表明：当钛酸酯偶联剂用量为2％（质量分数）,改性温度为50℃,改性时间为60min时,纳米MgO的表面改性效果最好。     

纳米Sm2O3的表面改性研究

用钛酸酯偶联剂,通过超声处理技术对纳米Sm2O3进行表面改性,并用沉降体积分析,红外光谱分析和TEM分析等手段对改性效果进行表征。研究了超声时间、分散介质、反应温度、偶联剂的种类及用量等因素对改性效果的影响,并对改性机理进行了探讨。结果表明:(1)钛酸酯系列偶联剂适用于纳米Sm2O3的表面改性,其中NDZ 102的改性效果最好;(2)改性的最佳工艺条件为:偶联剂最佳用量为纳米Sm2O3质量的6.5%,分散介质为丙酮,温度为25°C,超声时间为30~40 min;(3)经钛酸酯偶联剂改性后的纳米Sm2O3在有机溶剂中分散性大为改善;(4)纳米Sm2O3主要是通过化学吸附与钛酸酯偶联剂NDZ 102结合的。     

钛酸酯偶联剂表面改性纳米氧化锌

纳米氧化锌是一种高性能的无机材料,由于活性高,必须对其进行表面改性。本文通过对不同量钛酸酯偶联剂改性的纳米氧化锌活化指数的测定,得到常温下改性纳米氧化锌的钛酸酯偶联剂的最佳用量,并且探讨改性机理及最佳用量原因。     

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。