空心玻璃微珠填充MC尼龙复合材料的研究

对空心玻璃微珠填充铸型(MC)尼龙进行了系列研究,考察了空心玻璃微珠含量、粒径及表面处理对MC尼龙性能的影响。结果表明,空心玻璃微珠改性MC尼龙复合材料的物理性能和力学性能优良,当加入10％表面处理的空心玻璃微珠时,制品的收缩率下降,热变形温度提高20℃以上,制品具有填料分布均匀、外观光泽优良等优点。与未处理的空心玻璃微珠相比,填充经表面处理空心玻璃微珠的复合材料拉伸强度、弯曲强度、断裂伸长率分别提高了15．7％、12．2％和246％。空心玻璃微珠的粒径愈小,复合材料的力学性能愈好。一定用量的玻璃微珠填充MC尼龙不仅可以使材料保持较好的力学性能和耐热性能,而且能够降低MC尼龙复合材料的成本。     

空心玻璃微珠表面改性对双马来酰亚胺树脂性能的影响

介绍了用硅烷偶联剂(KH-550)与钛酸酯偶联剂处理空心玻璃微珠的方法；研究了处理剂用量与玻璃微珠加入量对改性双马来酰亚胺树脂压缩强度及马丁耐热温度的影响。结果表明,KH-550和钛酸酯偶联剂质量分数分别为1%、0．8%时,其偶联改性的效果最好。随着玻璃微珠质量分数的增加,体系压缩强度呈降低的趋势,马丁耐热温度提高,其中KH-550偶联改性的效果优于经钛酸酯偶联剂改性的效果。     

低密度BMC复合材料性能的研究

研究了四种不同种类的空心玻璃微珠的加入对团状模塑料(BMC)密度及性能的影响,观察空心玻璃微珠在BMC中的分散及破损情况以及空心玻璃微珠S38含量的变化对BMC密度及性能的影响。结果表明,随着微珠含量的增加密度及拉伸强度逐渐下降;微珠含量为5%时弯曲及冲击强度达到最大值。研究微珠的表面处理对BMC性能的影响,结果表明,微珠的表面处理能有效提高BMC的力学性能。     

空心玻璃微珠填充改性ABS复合材料的结构及性能

采用熔融共混挤出的方法,制备了不同空心玻璃微珠用量的丙烯腈-丁二烯-苯乙烯共聚物(ABS)复合材料。研究了空心玻璃微珠对复合材料力学性能、流动性和热稳定性的影响。结果表明,经过表面处理的空心玻璃微珠与ABS的相容性显著提高,空心玻璃微珠对复合材料的拉伸强度、弯曲强度和冲击强度影响很大,降低了复合材料的拉伸强度,当其质量分数分别为2%和8%时,复合材料获得最大弯曲强度和冲击强度。空心玻璃微珠的加入对复合材料的流动性和热稳定性均有一定程度的改善。     

不同偶联剂对环氧/玻璃微珠复合材料性能的影响

采用KH550、KH560、KH570三种硅烷偶联剂对空心玻璃微珠进行处理,进而使用熔融共混法制备了环氧/玻璃微珠复合材料。运用红外分析手段证实硅烷偶联剂均已成功接枝到空心玻璃微珠表面,借助DSC-TG和万能材料试验机研究了偶联剂种类对环氧/玻璃微珠复合材料固化反应、热稳定性和力学性能的影响。对测试结果的分析表明,空心玻璃微珠的表面处理并未改变环氧与氰酸酯间的固化反应速度。经偶联剂表面改性后,制得的环氧/玻璃微珠复合材料的弯曲和压缩强度显著提高,不同硅烷偶联剂的改性效果不同,其中KH-570改性的综合效果最优。     

粉煤灰空心玻璃微珠填充高密度聚乙烯的性能

采用从粉煤灰中提取的空心玻璃微珠,制备不同空心玻璃微珠含量的高密度聚乙烯复合材料,研究空心玻璃微珠对复合材料力学性能和结晶性能的影响.结果表明:随着空心玻璃微珠含量的增加,复合材料的拉伸强度逐步增大,弯曲强度和冲击强度先增大后减小,当空心玻璃微珠质量含量为5%时,弯曲强度和冲击强度达到最大.适量空心玻璃微珠的加入对复合材料的结晶性能有一定程度的改善.     

空心玻璃微珠/环氧复合材料的制备及性能研究

制备了空心玻璃微珠/环氧复合材料。通过力学性能、固化收缩率、热性能等测试考察了空心玻璃微珠粒径、填充量、硅烷偶联剂处理对树脂及固化物性能的影响。结果表明,硅烷偶联剂改善了空心玻璃微珠与树脂基体的相容性。复合材料的力学性能随着空心微珠粒径减小而增大。随着空心微珠填充量的加大,固化物拉伸强度有所降低,冲击强度和弯曲强度在空心玻璃微珠质量分数为2%时达到最大值,比纯树脂分别提高了30%和34.2%,同时材料的固化收缩率和密度降低,玻璃化转变温度升高。     

空心玻璃微珠填充改性PS复合材料的性能

采用熔融共混挤出的方法,制备不同空心玻璃微珠含量的PS复合材料,研究空心玻璃微珠对复合材料力学性能和热稳定性的影响.结果表明:经过表面处理的空心玻璃微珠与PS的相容性显著提高,空心玻璃微珠质量含量为5%时,复合材料获得最大拉伸强度、弯曲强度和冲击强度.     

空心玻璃微珠对乘用车专用阻尼材料性能的影响

以含有机硅苯乙烯-丙烯酸酯共聚乳液(简称"苯丙乳液")为基料,制备了含有2种不同粒径空心玻璃微珠的复合阻尼材料。采用傅里叶红外光谱仪和动态力学分析仪研究了乳胶膜的化学结构、阻尼性能和玻璃化转变温度;通过扫描电子显微镜表征了乳胶粒的粒径分布以及复合阻尼材料中玻璃微珠的分布及破碎情况;采用漆膜冲击仪、电子万能试验机和自制的阻尼系数测定仪研究了不同型号及其不同配比的空心玻璃微珠对复合阻尼材料的力学性能以及阻尼性能的影响。结果表明,粒径大的空心玻璃微珠相比于粒径小的空心玻璃微珠更易破碎,且粒径小的空心玻璃微珠与基体界面黏结性更好;而混合添加则对阻尼性能的提高更有利;随着基体内部混合空心玻璃微珠中粒径较小的微珠的质量分数的提高,复合阻尼材料的冲击强度和拉伸强度随之增大;当大粒径和小粒径空心玻璃微珠的质量比为1:1,且其总含量为15%(质量分数,下同)时,复合阻尼材料的阻尼性能为最佳。     

BMI树脂基轻质耐压复合材料的制备及性能研究

采用空心玻璃微珠填充改性双马来酰亚胺(BMI)树脂,研究了玻璃微珠用量和粒径以及表面处理的玻璃微珠,对材料压缩性能以及吸水性的影响。结果表明小粒径(10μm)较大粒径(70μm)玻璃微珠填充改性双马来酰亚胺树脂的压缩强度降低缓慢,经表面处理后可获得最佳效果。少量地加入玻璃微珠可降低环氧树脂的吸水性,但随着玻璃微珠含量的增大,体系的吸水性会随之增加。当玻璃微珠含量为30%时,复合材料密度降至0.74gcm3,压缩强度仍可以达到68.5MPa。     

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.     

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。     

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.