环保丁腈橡胶与传统丁腈橡胶的性能对比

对环保型与传统丁腈橡胶(NBR)进行了微观结构、相对分子量及其分布、硫化胶的物理机械性能、混炼胶硫化特性、压缩永久变形、耐老化性能以及制品的性能进行了对比研究。结果表明,环保型NBR 3305 E、2907 E与传统NBR 3305、2907的相对分子质量及其分布、微观结构组成略有不同,混炼胶硫化特性、物理机械性能、压缩永久变形以及耐老化等性能相当。使用NBR 3305与NBR 3305 E制备密封制品时物理机械性能和预期使用寿命基本相同,使用NBR 2907 E制备发泡橡胶制品的密度比NBR 2907制品的略低。     

国内同类丁腈橡胶性能对比

针对市场上畅销的丁腈橡胶(NBR),从结构组成、硫化特性等方面进行了对比,结果表明,结合丙烯腈质量分数为28%的NBR中,JSR-240S结合丙烯腈质量分数最低,NBR2907E的相对分子质量较大,NBR2875、NBR2880Z硫化速度较快,NBR2907E和NBR2865的物理机械性能相当,NBR2875压缩永久变形最小,JSR-240S和NBR2907E老化性能较好;结合丙烯腈质量分数为33%的NBR中,NBR1052的结合丙烯腈质量分数、相对分子质量最低,分子质量分布最窄,NBR3355、NBR3305E、JSR-230S硫化速度较快,JSR-230S、NBR3355、NBR3305E的物理机械性能基本相同,NBR3305E和NBR3355压缩永久变形较小,NBR3305E老化性能最好;结合丙烯腈质量分数为40%的NBR中,JSR-220S结合丙烯腈质量分数最高、相对分子质量最低且相对分子质量分布最窄,南帝4155硫化速度最快,南帝4155和JSR-220S强度较高,4155LT压缩永久变形和老化性能最好。     

混炼工艺对丁腈橡胶改性白炭黑填充溶聚丁苯橡胶性能的影响

研究3种混炼工艺对丁腈橡胶(NBR)改性白炭黑填充溶聚丁苯橡胶(SSBR)性能的影响。结果表明:无论采用哪种混炼工艺,以NBR1846或NBR3305改性白炭黑填充SSBR胶料的t90缩短,硫化速率加快,硫化胶的抗湿滑性能提高,滚动阻力降低;当采用先混炼NBR和白炭黑、再加SSBR的工艺时,NBR3305改性白炭黑填充SSBR硫化胶的动态力学性能最好。     

NBR在白炭黑表面吸附对SSBR胶料性能的影响

以高乙烯基溶聚丁苯橡胶（SSBR2557A）为研究对象,研究了不同丙烯腈含量的2种丁腈橡胶（NBR1846和NBR3305）对白炭黑填充的SSBR2557A胶料加工性能、力学性能和动态性能的影响。结果表明,加入NBR,缩短了混炼胶的硫化时间,提高了硫化速度。加入NBR除对硫化胶的压缩生热和永久变形造成不利影响外,对其他力学性能都有不同程度的改善,尤其是耐磨耗性能改善显著。动态力学性能（DMA）测试表明,加入NBR,使硫化胶在0℃时的tanδ值升高,60℃时的tanδ值降低,NBR3305的影响尤为显著。     

兰州石化公司丁腈橡胶与JSR丁腈橡胶性能对比

对兰州石化公司、JSR公司同类丁腈橡胶(NBR)产品对相对分子质量及其分布、结构组成、硫变特性、物理机械性能、老化性能、耐油性能、耐磨性能和玻璃化转变温度等进行了对比研究。结果表明,NBR2907的重均相对分子质量和数均相对分子质量比JSR241、JSR240S高,且相对分子质量分布比JSR241、240S宽;结构组成中结合丙烯腈含量比JSR240S、JSR241高;NBR2907的加工安全性更好,但硫化速度比JSR241、240S慢;NBR2907与JSR240S物理机械性能相当,比JSR241的拉伸强度、300%定伸应力稍大;老化性能、磨耗性能和耐油性能比JSR241、JSR240S稍好;低温性能比JSR241、JSR240S稍差;NBR3305的相对分子质量及其分布、物理机械性能、耐磨性能、耐油性能与JSR230S相当;NBR3305结构组成中结合丙烯腈含量略高,焦烧时间长,硫化速度慢;NBR3305的老化性能比JSR230S稍好,低温性能较JSR230S稍差。     

极性橡胶改性白炭黑对全钢载重子午胎胎面胶性能的影响

利用丁腈橡胶(NBR)强极性的氰基与白炭黑表面的羟基之间的强相互作用,以两种不同丙烯腈含量的丁腈橡胶NBR1846和NBR3305改性白炭黑,并将之应用于全钢载重子午线轮胎胎面胶配方中。研究了NBR改性白炭黑对胎面胶加工性能、基本物理机械性能和动态性能的影响。研究结果表明,NBR-白炭黑的加入可以极大的提高胎面胶的硫化速度,当NBR用量为8phr时,硫化胶具有优良的综合物理机械性能。当采用NBR与白炭黑先共混的工艺时,硫化胶的物理机械性能最佳,而且硫化胶的磨耗体积和压缩疲劳温升也较小。动态力学测试分析表明,NBR用量为8phr时,胎面胶即具有高的抗湿滑性又具有低的滚动阻力,相对于与NBR1846,NBR3305改性白炭黑胶料的抗湿滑性能更高,滚动阻力也更低。     

受阻酚抗氧剂对NBR/WCB共混胶耐热老化性能的影响

研究了抗氧剂2-叔丁基-6-(3-特丁基-2-羟基-5-甲基苯基)-4-甲基苯酚丙烯酸酯(简称GM)、抗氧剂264和抗氧剂2246对NBR/WCB共混胶的硫化特性、力学性能和耐热老化性能的影响,并通过TG分析表征NBR/WCB共混胶的耐热稳定性。结果表明,与抗氧剂264和抗氧剂2246相比,抗氧剂GM对NBR/WCB共混胶具有防止焦烧、加快硫化速度和软化胶料的作用。添加抗氧剂GM的共混胶比加入抗氧剂264和2246的共混胶具有更优异的耐热老化性能。TG分析表明,在3种抗氧剂中,加入抗氧剂GM的NBR/WCB共混胶的耐热稳定性最高。     

NBR/PVC热塑性弹性体耐热老化性能研究

考察了硫化体系、PVC聚合度、DOP用量、抗氧剂种类及用量对丁腈橡胶／聚氯乙烯(NBR／PVC)热塑性弹性体(TPE)的耐热老化性能的影响。试验结果表明：NBR／PVC：的质量比为70：30时，酚醛树脂硫化体系制备的TPE的耐热老化性能最好；增加PV(：的聚合度，TPE的耐热老化性能提高；DOP用量越大。TPE的耐热老化性能越差；抗氧剂2246对TPE的耐热老化性能最好，其最佳用量为2．0份。     

双酚单丙烯酸酯抗氧剂对NBR/WCB混炼胶耐热老化性能的影响

研究了抗氧剂GM对NBR/WCB混炼胶的硫化特性、力学性能和耐热老化性能的影响,并通过TG分析表征混炼胶的耐热稳定性。结果表明,抗氧剂GM具有防止焦烧和加快硫化速度的作用,随着GM用量的增大,混炼胶的拉伸强度和伸长率升高,撕裂强度和硬度下降。混炼胶的耐热老化性能随抗氧剂GM用量增大而提高,GM用量以4份为宜。TG分析表明,加入抗氧剂GM后,混炼胶的耐热稳定性提高。     

偶联剂γ-氨丙基三乙氧基硅烷对炭黑增强丁腈橡胶性能的影响

考察了偶联剂γ-氨丙基三乙氧基硅烷(KH550)的用量对炭黑增强丁腈橡胶(NBR)硫化胶的交联密度、物理机械性能及动态性能的影响。结果表明,KH550的加入明显提高了NBR硫化胶的交联密度,且使NBR硫化胶的耐老化性能得到改善;当KH550用量为2份时,NBR硫化胶具有较佳的物理机械性能,NBR硫化胶的Payne效应最小,在高、低应变下均具有较低的滞后损失和动态温升,同时改善了老化前后NBR硫化胶的耐屈挠性。     

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.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

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。     

Inorganic/organic nanocomposite coatings: The next step in coating performance

Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.