混炼硅橡胶

硅橡胶是有机硅产品中数量最大的一类(见图1),由各种二氯硅烷经过水解、缩聚而得到的一种元素有机弹性体,分热硫化型(高温硫化硅胶HTV)、室温硫化型(RTV),其中室温硫化型又分缩聚反应型和加成反应型。高温硅橡胶主要用于制造各种硅橡胶制品,而室温硅橡胶则主要是作     

加成反应型硅橡胶的研究进展

简介硅橡胶的分类及硫化方法，重点描述加成反应型硅橡胶的硫化机理及加成硫化反应的影响因素。指出铂配合物是硅橡胶加成硫化反应最为有效的催化剂．其催化机理较为复杂，存在多种类型的反应；抑制剂和防中毒剂也影响硅橡胶的硫化效果。现阶段，国内外对加成反应型硅橡胶的研究多集中在提高强度、改善耐热性和改进注射成型方法等方面。     

三个品种系列硅橡胶通过技术鉴定

吉林化学工业公司研究院承担的国家科委“六五”攻关项目——乙酸型单组分室温硫化硅橡胶、加成型室温硫化硅橡胶、加成型热硫化硅橡胶以及它们的应用研究,已     

单组分室温硫化硅橡胶的配制(一)

介绍了单组分室温硫化硅橡胶的分类、硫化机理和配制方法；重点介绍了脱醋酸型室温硫化硅橡胶的配制。     

缩合型室温硫化硅橡胶的技术进展

由于室温硫化(RTV)硅橡胶性能优异、价格便宜、使用方便,获得了迅速发展。其产量已超过热硫化(HTV)型硅橡胶。 RTV硅橡胶按包装贮存形式可分单组份和双组份硅橡胶;按固化反应机理可分加成型和缩合型硅橡胶。用于缩合型的RTV生胶主要为羟基封端的有机聚硅氧烷。聚合     

改性氢氧化钙填充硅橡胶的制备与性能研究

通过添加改性氢氧化钙降低硫化剂双25硫化硅橡胶的气味等级,并研究改性氢氧化钙对硅橡胶硫化特性、动态力学性能和物理性能等的影响。结果表明：改性氢氧化钙会影响硅橡胶的硫化过程,吸收硫化过程中产生的副产物,促进硫化反应,增大硅橡胶的交联密度、邵尔A型硬度、定伸应力和拉伸强度;当改性氢氧化钙用量为2份时,硅橡胶的综合性能最好。     

单组分室温硫化硅橡胶制备及应用

介绍了室温硫化硅橡胶种类与应用范围。以脱醋酸型单组分室温硫化硅橡胶为例,介绍其胶料合成的预缩合反应和胶料接触水分发生的交联硫化反应原理、合成工艺及物料配比等,讨论了各组分对单组分室温硫化硅橡胶性能的影响,归纳了单组分室温硫化硅橡胶的主要质量指标的测定方法。     

单组分室温硫化硅橡胶的配制(六)

详细介绍了能粘聚烯烃塑料、乙丙橡胶、硅橡胶、氯化聚乙殊及表面消光的脱酮肟型单组分室温硫化(RTV—1)硅橡胶胶粘剂和阻燃、导电、低臭味、深层快硫化型脱酮肟型RTV—1硅橡胶密封剂的配制方法。     

脱醇型单组分室温硫化硅橡胶的制备

为解决脱醇型室温硫化硅橡胶存在的黏度高峰、贮存期短、易黄变等问题,以α,ω-二羟基聚二甲基硅氧烷(107硅橡胶)为基料,添加自制醇型一体化助剂、二甲基硅油、纳米碳酸钙等,制得脱醇型单组分室温硫化硅橡胶。研究了制备工艺,活性纳米碳酸钙、二甲基硅油、自制醇型一体化助剂用量对脱醇型室温硫化硅橡胶性能的影响。结果表明,较佳配方为：300份黏度80 000 mPa·s的107硅橡胶,100份黏度20 000 mPa·s的107硅橡胶,40份二甲基硅油,460份活性纳米碳酸钙,40份钛白粉,60份自制醇型一体化助剂。采用此配方制得的脱醇型室温硫化硅橡胶贮存稳定性优良、耐黄变性佳、力学性能好、深层硫化速率快,其拉伸强度为1.32 MPa,拉断伸长率为503%,深层硫化时间为24 h。加速老化试验后,表干时间、深层硫化时间、外观颜色均无明显变化。     

硅胶工艺品的制作研究

室温硫化硅橡胶在室温下无需加热、加压,即可就地硫化,使用方便、快捷。本文采用手工翻模成型方法,使用缩合型双组分室温硫化硅橡胶制造了硅胶磁吸制品。     

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。