ABS/改性抗菌纳米ZnO的力学及抑菌性能

采用偶联剂处理法对抗菌纳米ZnO表面进行改性,制备了丙烯腈-丁二烯-苯乙烯共聚物(ABS)／改性抗菌纳米ZnO复合材料。结果表明:改性抗菌纳米ZnO质量分数为3％时,复合材料的改性效果最佳,其拉伸强度、断裂伸长率、硬度、缺口冲击强度和无缺口冲击强度分别较纯ABS树脂提高37．4％,3．4％,44．0％,15．8％,11．8％;复合材料对大肠杆菌、金色葡萄球菌的抑菌率分别达到76．3％及84．0％。     

PC/改性ABS复合材料的制备与性能

在传统的丙烯腈-丁二烯-苯乙烯共聚物(ABS)乳液接枝聚合中加入甲基丙烯酸甲酯(MMA),制得了改性ABS,然后与聚碳酸酯(PC)共混挤出，制得了PC/改性ABS复合材料。研究了MMA用量对PC/改性ABS复合材料的熔体流动速率(MFR)、维卡软化温度、力学性能的影响。结果表明：随着MMA用量的增加，PC/改性ABS复合材料的MFR、拉伸强度、弯曲强度和缺口冲击强度均先升高后降低。当MMA质量分数为20%时，PC/改性ABS复合材料的拉伸强度和弯曲强度均达到最大，分别为48.9 MPa和63.2 MPa;当MMA质量分数为30%时，PC/改性ABS复合材料的缺口冲击强度为41.0 kJ/m²;当MMA质量分数不高于30%时，与PC/ABS复合材料相比，PC/改性ABS复合材料的维卡软化温度更高。     

玻璃纤维增强PVC/ABS合金材料性能的研究

研究不同玻璃纤维(GF)填充量和不同处理工艺对PVC/ABS合金力学性能以及维卡软化温度的影响.研究结果表明:随着玻璃纤维添加份数的增加,PVC/ABS合金的拉伸性能和维卡软化温度有不同程度的提高,缺口冲击强度有所下降.其中经硅烷偶联剂改性过的玻璃纤维力学性能和维卡软化温度都会好于未改性的玻璃纤维.     

LLDPE/纳米ZnO复合材料的制备与性能研究

将改性纳米ZnO与线型低密度聚乙烯(LLDPE)熔融共混、制备了LLDPE/纳米ZnO复合材料。通过SEM观察纳米ZnO粒子在LLDPE基体中的分散情况;研究了复合材料的力学性能及维卡软化点。结果表明:改性纳米ZnO的加入可提高LLDPE的力学性能和维卡软化点。其中,复合材料的拉伸强度、断裂伸长率、冲击强度、弯曲强度的最大值分别比LLDPE提高了17.00%、13.42%、9.90%、7.04%。     

纳米ZnO/PVC复合材料的制备及其性能研究

以钛酸酯偶联剂HY-201对纳米ZnO进行改性,通过双辊混炼法制备了改性纳米ZnO/PVC复合材料。研究了纳米改性复合材料的冲击强度、拉伸强度、维卡软化温度、邵氏硬度的变化规律。结果表明,随改性纳米ZnO份数的增加,复合材料的冲击强度、拉伸强度呈先上升后下降的趋势,而维卡软化温度以及邵氏硬度呈现上升后逐渐平稳的的趋势。     

PP/纳米ZnO的紫外光老化性能

将纳米ZnO(nano-ZnO)用钛酸酯偶联剂表面处理后制备聚丙烯(PP)/nano-ZnO复合材料。研究了nano-ZnO含量对复合材料耐老化性能的影响。nano-ZnO可明显改善PP树脂的紫外光老化性能。当w(nano-ZnO)为3%时,复合材料老化前后的性能差和纯PP树脂老化前后的性能差分别为:拉伸强度1.9 MPa和3.1 MPa、断裂伸长率为29.0%和66.7%、缺口冲击强度为1.1 kJ/m~2和2.9 kJ/m~2、无缺口冲击强度为1.5 kJ/m~2和3.2 kJ/m~2、球压痕硬度为4.8 MPa和5.8 MPa、维卡软化温度为3.3℃和7.0℃。     

PS/改性纳米CaCO3的共混挤出制备

通过共混挤出方法制备聚苯乙烯(PS)／改性纳米CaCO3复合材料,分析测试其冲击强度和弯曲性能及维卡软化温度,并表征了纳米CaC,3子在PS中的分散状态。当w(nano-CaCO3)为2．5％-5．0％时,复合材料的冲击强度和弯曲强度均显著提高,对热性能影响较小,维卡软化温度仍维持在98℃左右。透射电子显微镜观测表明,纳米CaCO3粒子在复合材料中仍呈纳米分散状态。     

环氧树脂对PVC/ABS合金性能的影响

在PVC/ABS合金中加入环氧树脂(EP),研究了EP用量对PVC/ABS合金加工性能、力学性能以及维卡软化点的影响,结果表明,添加EP不利于PVC/ABS合金的加工,在低用量时,PVC/ABS合金的维卡软化点和拉伸强度得到明显改善,提高用量反而会使其维卡软化点降低;复合材料的缺口冲击强度随EP用量的增加下降明显。     

纳米莫来石在聚苯乙烯改性中的应用研究

采用优质煤系高岭土煅烧制备的纳米莫来石(nano-mullite)对聚苯乙烯(polystyrene)进行改性,通过机械共混的方法制备了PS/nano-mullite复合材料.探讨了复合材料中纳米莫来石的含量对改性PS的力学性能、耐热性能以及热流动性的影响.实验结果表明:适量的纳米莫来石加入后,复合材料的拉伸强度,缺口冲击强度,维卡软化点温度和热流动性能均有较大的提高.     

尼龙66/纳米SiO2复合材料的形态和力学性能

通过熔融共混法制备了尼龙66／纳米SiO2复合材料，并对复合材料的力学性能、动态力学性能以及拉伸断面形态进行了研究。结果表明，随着纳米SiO2含量的增加，复合材料的拉伸强度在纳米SiO2质量分数为3％时达到最大．较纯尼龙66提高7．6％；复合材料的简支梁缺口冲击强度随纳米SiO2含量的增加而增加，在纳米SiO2质量分数为4％时，比纯尼龙的简支梁缺口冲击强度提高51．3％。复合材料储能模量和损耗模量也较纯尼龙66有所增加；复合材料的断面出现明显的塑性变形。     

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。