缩合型室温硫化硅橡胶的粘接性能及粘接机理分析

研究了缩合型单组分室温硫化硅橡胶（ＲＴＶ１）和缩合型双组分室温硫化硅橡胶（ＲＴＶ２）的粘接性能。结果表明：以苯胺甲基三乙氧基硅烷为交联剂的ＲＴＶ１具有良好的粘接性能;涂底胶可以提高ＲＴＶ２的粘接性能。应用溶液浸蚀法研究了室温硫化硅橡胶对多种被粘材料的界面相互作用,发现ＲＴＶ１对不锈钢的粘接力主要为色散力和酸碱作用,对铝合金的粘接力,除色散作用和酸碱作用外还有化学键作用。     

非催化室温硫化硅橡胶的力学性能

从拉伸强度，硬度，扯断伸长率的变化及粘合强度等方面研究了用硅氮化合物交联剂硫化的室温硫化硅橡胶的力学性能，并与用Ｓｉ（ＯＥｔ）４交联的硫化胶相比较，前者在３５０℃仍能保持较好的力学性能，具有很好的热稳定性，而后者在２５０℃时力学性能下降４０％左右；而且前者对金属和高分子材料的粘合强度比后者提高３－７倍。讨论了催化剂，胶料对硫化胶力学的性能的影响。     

双组份缩合型室温硫化硅橡胶制备技术的讨论

以疏水处理气相ＳＯ２填充补强Ｍｎ＝４０００～４５０００范围内的羟基封端聚二甲基硅氧烷制备双组份室温硫化硅橡胶（ＲＩＶ－２）与混用高低分子量生胶或接枝硅橡胶做基胶相比，前者可以适度交联形成强韧的弹性体。     

平衡硫化体系硫化天然橡胶的性能研究

对平衡硫化（ＥＣ）体系硫化天然橡胶（ＮＲ）的性能进行了研究，并与半有效硫化（ＳＥＶ）体系和传统硫化（ＣＶ）体系硫化ＮＲ进行了对比。结果表明，ＥＣ体系返原作用略高于ＳＥＶ体系，明显低于ＣＶ体系，硫化６ｈ时的返原率依次为７．７％，０．４％和３４．０％；与ＳＥＶ和ＣＶ体系相比，ＥＣ体系ＮＲ硫化胶拉伸强度、撕裂强度和３００％定伸应力高，生热低，耐磨性和耐屈挠性好。ＥＣ体系ＮＲ硫化胶的耐热氧老化性能优于ＳＥＶ体系，更优于ＣＶ体系。     

降低MVQ硫化胶模量的研究

探讨了用增塑剂二甲基硅油、丙三醇和１，２－丙二醇降低甲基乙烯基硅橡胶（ＭＶＱ）硫化胶模量的途径。结果表明，二甲基硅油可降低ＭＶＱ硫化胶的模量，但硫化胶扯断永久变形和压缩永久变形较大；丙三醇对ＭＶＱ硫化胶性能的影响与其结构控制剂有关，用二苯基硅二醇作结构控制剂时，可采用丙三醇降低硫化胶模量，用羟基硅油作结构控制剂时，不宜采用丙三醇调节硫化胶的模量；１，２－丙二醇可显著降低ＭＶＱ硫化胶模量，而且硫化胶的力学性能和耐热老化性能十分优异。     

甲基丙烯酸对氢氧化铝填充丁苯橡胶性能的影响

将甲基丙烯酸（MAA）用作Al(OH）3填充丁苯橡胶（SBR）复合材料的添加剂，结果表明，在高填充Al(OH）3的SBR中加入MAA可以较大幅度地提高其过氧化物硫化胶的力学性能。当Al(OH）3用量为150份（质量份，下同）时，随着MAA用量增加，SBR硫化胶的邵尔A型硬度和定伸应力逐渐增大，拉伸强度和撕裂强度有较大幅度的提高，当MAA用量为20份时，随着Al(OH）3用量增加，SBR硫化胶的邵尔A型硬度、定伸应力和撕裂强度逐渐增大，拉伸强度在Al(OH）3填充量为25份时最大，大量填充Al(OH）3的SBR硫化胶的阻燃性能较好，氧指数受MAA用量的影响较小，该SBR硫化胶亦具有良好的热空气老化性能。     

甲基丙烯酸镁对EVM硫化胶性能的影响

将不饱和羟酸金属盐与乙烯-乙酸乙烯酯共聚物（EVM）共混制备硫化胶，研究了甲基丙烯酸镁（MDMA）对过氧化物硫化的EVM的硫化特性，物理机械性能以及耐热氧老化性能的影响。结果表明，MDMA能提高EVM胶料的硫化速度；MDMA显著地提高了EVM硫化胶的物理机械性能，其用量为20-50份时，硫化胶的拉伸强度保持在20MPa以上；与高耐磨炉黑增强的硫化胶相比，MDMA增强的EVM硫化胶具有较好的耐热氧老化性能。     

适用于胎体胶配方的低碘高耐磨炉黑

实验表明，低碘炭黑（CB1）具有比传统炭黑N660（CB6）更好的焦烧安全性和硫化性能，可以进一步提高生产率；CB1炭黑填充胶的定伸应力比传统炭黑填充胶的高；在严苛条件下使用时，CB1填充胶的耐疲劳性比传统炭黑填充胶的高（用于NR配方时，屈挠疲劳性可提高20％）；CB1填充胶的生热稍比CB6填充胶的高（高4～5℃）；CB1炭黑填充胶的粘合性更好；CB1填充胶老化后的应力-应变性能优越。已经清楚地证明，CB1炭黑比传统炭黑更适用于胎体胶配方。     

橡胶型乙烯-醋酸乙烯共聚物配方及老化性能研究

研究了橡胶型乙烯－醋酸乙烯共聚物（ＥＶＭ）的配方及热氧老化性能。试验结果表明：ＥＶＭ具有优异的热空气老化性能，经１７５℃×７２ｈ老化后仍有很高的拉伸强度和扯断伸长率保持率；需采用过氧化物进行硫化，同时并用适量的三烯丙基异氰脲酸酯可以显改善ＥＶＭ的压缩永久变形性能；它是一种典型非自补强性橡胶，需加入适量的补强填充剂；聚酯增塑剂可以在一定程度上降低ＥＶＭ的硬度，而对老化性能影响不大；防老剂ＲＤ可赋予     

影响ACM／FKM硫化胶耐热老化性能的配方因素

研究了共混比、炭黑品种及用量、软化剂和防老剂种类等配方因素对丙烯酸酯橡胶（ACM）／氟橡胶（FKM）硫化胶耐热老化性能的影响。结果表明,经180℃×48h热老化后,ACM／FKM硫化胶的力学性能保持率随ACM用量的增加而降低;加入0～50质量份炭黑补强的硫化胶耐热老化性能随炭黑用量增加而提高;使用软化剂硅油的硫化胶的耐热老化性能较好;添加防老剂可提高共混硫化胶的耐热老化性能,其中防老剂RD和A效果较好。     

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。