聚酯/聚醚混合型增塑剂对乙烯丙烯酸酯橡胶性能的影响

研究不同牌号乙烯丙烯酸酯橡胶(AEM)及聚酯/聚醚混合型增塑剂种类和用量对硫化胶性能的影响。结果表明:AEM Vamac G硫化胶的耐低温性能较好,而AEM Vamac GLS硫化胶的物理性能、耐老化性能和耐油性能较好,选择并用比为50/50的AEM Vamac G/AEM Vamac GLS并用胶作为主体材料,硫化胶的物理性能、耐油性能和耐低温性能可更好地平衡;添加增塑剂TP-759的硫化胶的耐低温性能较好,添加增塑剂RS-735的硫化胶的耐热老化性能较好,两者耐油性能相当;随着增塑剂用量的增大,硫化胶的耐低温性能提高,拉伸强度降低,拉断伸长率和压缩永久变形增大,油浸泡后体积变化率减小。     

硅橡胶/溶聚丁苯橡胶并用胶在胎面胶中的应用研究

采用母胶法混炼工艺制备硅橡胶(MVQ)/溶聚丁苯橡胶(SSBR)并用胶,研究MVQ/SSBR并用比对胎面胶性能的影响。结果表明:随着MVQ用量的增大,胶料的最大转矩减小,正硫化时间变化不大;硫化胶的物理性能下降,耐磨性能提高,抗湿滑性能改善,压缩生热升高。     

共混比对AEM/MVQ共混胶性能的影响

研究了共混比对乙烯丙烯酸酯橡胶/甲基乙烯基硅橡胶（AEM/MVQ）共混胶硫化特性、力学性能、耐热老化性能、耐油性能、压缩永久变形及动态力学性能的影响。结果表明,随着AEM用量的增加,共混胶正硫化时间延长,拉伸强度、拉断伸长率和撕裂强度均增加,耐油性能提高;随着MVQ用量的增加,共混胶耐热老化性能提高,压缩永久变形减小。DMA数据显示,AEM和MVQ具有良好的相容性,共混胶低温性能比纯AEM橡胶有所改善。     

硫化条件对FKM/MVQ并用胶性能的影响

采用机械共混法制备氟橡胶(FKM)/甲基乙烯基硅橡胶(MVQ)并用胶,研究硫化条件对FKM/MVQ并用胶性能的影响。结果表明,随着一段硫化温度的升高,FKM/MVQ并用胶t10和t90缩短,邵尔A型硬度和撕裂强度变化不大,定伸应力和拉伸强度先增大后减小;当一段硫化条件为165℃×t90、二段硫化条件为250℃×4h时,FKM/MVQ并用胶的综合物理性能较好。     

甲基乙烯基硅橡胶/溶聚丁苯橡胶并用胶性能的研究

研究甲基乙烯基硅橡胶(MVQ)/溶聚丁苯橡胶(SSBR)并用胶的性能,探讨并用胶表面能与耐磨和抗湿滑性能的关系。结果表明:随着MVQ用量的增大,MVQ/SSBR并用胶的物理性能和抗湿滑性能下降,摩擦因数和表面能减小,耐磨性能先提高后降低;当MVQ用量为20份时,MVQ/SSBR并用胶的综合性能最佳;MVQ/SSBR并用胶的表面能与摩擦因数和抗湿滑性能成正比;当MVQ用量小于20份时,MVQ/SSBR并用胶的表面能与耐磨性能成正比。     

氟橡胶/硅橡胶/氟硅橡胶并用胶的性能研究

研究氟橡胶(FKM)/硅橡胶(MVQ)/氟硅橡胶(FSR)并用胶的性能。试验结果表明:FKM并用MVQ后,并用胶的物理性能和耐油性能下降,但回弹值和耐低温性能明显改善;采用FSR部分替代MVQ后,随着FSR用量的增大,并用胶的相容性改善,拉伸强度和拉断伸长率增大,耐油性能提高,耐低温性能变化不大。     

丙烯酸酯橡胶/乙烯丙烯酸酯橡胶并用胶性能的研究

制备丙烯酸酯橡胶(ACM)/乙烯丙烯酸酯橡胶(AEM)并用胶,并对其性能进行研究。结果表明:ACM与AEM并用能够实现共硫化;与ACM相比,ACM/AEM并用胶的拉伸强度增大,耐热空气老化性能和耐低温性能得到改善,耐油性能有所下降。当ACM/AEM并用比为60/40、炭黑N550和N774用量分别为40份、1#硫化剂用量为1.5份时,ACM/AEM并用胶的物理性能最佳。     

以三氧化二锑为协效剂的复合阻燃剂对MVQ硫化胶阻燃性能的影响

分别研究硼酸锌／三氧化二锑、氢氧化铝／三氧化二锑和三氧化钼／三氧化二锑并用体系对甲基乙烯基硅橡胶(MVQ)硫化胶阻燃性能和物理性能的影响。结果表明，硼酸锌／三氧化二锑并用体系可有效提高MVQ硫化胶的阻燃性能，并能保持较好的物理性能；氢氧化铝／三氧化二锑并用体系的阻燃效果十分显著，但MVQ硫化胶的发烟量稍大；三氧化钼／三氧化二锑并用体系虽可减小MVQ硫化胶的发烟量，但阻燃效果不明显，且硫化胶的物理性能受损严重。     

配方因素对CM/EPDM并用胶性能的影响

研究氯化聚乙烯橡胶(CM)和EPDM用量及硫化体系对CM/EPDM并用胶性能的影响.结果表明,随着CM用量的增大,并用胶交联密度降低,拉伸强度增大;随着EPDM用量的增大,并用胶t90缩短,撕裂强度减小;硫黄硫化体系的硫化效率较低,并用胶撕裂强度和拉断伸长率较大;过氧化物硫化体系硫化效率适中,并用胶综合物理性能最好;噻唑类硫化体系的硫化效率最高,并用胶拉伸性能和耐热空气老化性能良好.     

NBR/AEM并用比例对胶料性能的影响

本文主要研究了NBR/AEM不同井用比例对共混胶料的硫化性能、力学性能、耐老化性能和耐油性能的影响,结果表明;随着AEM含量的增加,NBR/AEM胶料的焦烧时间延长,硫化速度降低.并用硫化胶的拉伸强度、撕裂强度和压缩永久变形都逐渐减小,拉断伸长率先减小后增加,硬度和100％定伸应力先增大后减小,耐老化性能得到改善,耐油性能下降.     

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。