白炭黑在溶聚丁苯橡胶中的分散性研究

研究白炭黑和偶联剂Si69用量对溶聚丁苯橡胶(SSBR)胶料白炭黑分散性以及物理性能的影响。结果表明:随着白炭黑用量的增大,SSBR硫化胶的白炭黑分散性下降,硬度增大,拉伸强度和撕裂强度在白炭黑用量为60份时最大;在填充65份白炭黑的SSBR胶料中,当偶联剂Si69用量为6份时,SSBR硫化胶的白炭黑分散性和物理性能最好。     

SSBR和ESBR胎面胶性能研究

研究炭黑或白炭黑补强溶聚丁苯橡胶(SSBR)和乳聚丁苯橡胶(ESBR)胎面胶的性能.结果表明,SSBR与白炭黑的界面作用强于ESBR;当采用白炭黑补强时,SSBR硫化胶的物理性能优于ESBR,而采用炭黑补强时,SSBR硫化胶的物理性能无明显优势;与炭黑补强SBR硫化胶相比,白炭黑补强SBR硫化胶的抗湿滑性能较好,滚动阻力较低,但耐磨性能较差,其中白炭黑补强SSBR硫化胶的抗湿滑性能最突出.     

硅烷偶联剂对丁腈橡胶和溶聚丁苯橡胶性能的影响

研究了双-(γ-三乙氧基硅基丙基)四硫化物(Si 69)作为硫给予体对硫黄硫化体系丁腈橡胶(NBR)和溶聚丁苯橡胶(SSBR)硫化特性及力学性能的影响。结果表明,Si 69参与了NBR和SSBR的硫化,导致NBR和SSBR的焦烧时间明显缩短,其中对SSBR焦烧时间的影响更大;但随着硫化温度的提高,Si 69对胶料焦烧时间的影响减弱。对添加Si 69后混炼胶的前期硫化行为进行一级动力学模拟发现,Si 69会降低NBR的硫化反应速率,使活化能减小,而对SSBR的硫化反应速率影响不大。硫化胶力学性能研究表明,随着硫化时间的延长,添加Si 69有利于提高NBR硫化胶的力学性能;但是与NBR相反,硫化时间过长,添加Si 69后SSBR硫化胶的力学性能明显下降。     

微晶纤维素-SiO2杂化纳米填料的制备及应用研究

以正硅酸乙酯为硅源,采用“微反应器”技术,在微晶纤维素(MCC)表面负载纳米级别的SiO₂,得到MCC-SiO2杂化体。红外光谱(IR)热失重(TG)和扫描电镜分析(SEM)表明不同形态结构的纳米级别的SiO2成功的负载在微晶纤维素表面。将MCC-SiO2杂化体应用于橡胶体系,结果发现MCC杂化改性后补强性能提高,硫化胶的tanδ值在0℃时明显提高,而在60℃时下降。SEM分析测试结果表明MCC杂化改性后在橡胶基体粒径变小,达到原位微细化的目的,同时MCC-橡胶的界面结合性能提高。     

充油溶聚丁苯橡胶与乳聚丁苯橡胶结构和性能对比的研究

对充油溶聚丁苯橡胶(SSBR)和乳聚丁苯橡胶(ESBR)的结构和性能进行对比研究。结果表明:充油SSBR与ESBR的微观结构相差较大,SSBR的1,2-结构和顺式-1,4-结构质量分数较大,相对分子质量分布较窄,滞后损失小;SSBR HP755R硫化胶具有良好的物理性能、耐磨性能、抗湿滑性能和较低的滚动阻力,SSBR HP755R适用于轮胎胎面胶;SSBR2564S硫化胶的物理性能和抗湿滑性能略差于、滚动阻力略高于SSBR HP755R硫化胶。     

不同炭黑对溶聚丁苯橡胶性能的影响

研究不同炭黑对溶聚丁苯橡胶(SSBR)性能的影响。结果表明:在密炼(一段混炼)过程中炭黑N330填充SSBR胶料的温度和功率均较高,不同炭黑填充SSBR胶料的粘-切依赖性大致相同;炭黑粒径越小、结构度越高,其填充SSBR胶料的Payne效应越显著;炭黑SP5000填充SSBR胶料的焦烧时间最长,炭黑N115,N234,N330和N550填充SSBR胶料的硫化速率稍快;粒径较小的炭黑填充SSBR硫化胶的物理性能和耐磨性能较优,但压缩温升较高;粒径相近而结构度较高的炭黑填充SSBR硫化胶的物理性能优于结构度较低的炭黑填充硫化胶;粒径较大的炭黑填充SSBR硫化胶的抗湿滑性能较好和滚动阻力较低,炭黑N774填充SSBR硫化胶的抗湿滑性能最好,且滚动阻力最低。     

溶聚丁苯橡胶在绿色轮胎胎面胶中的应用

研究不同牌号溶聚丁苯橡胶(SSBR)在绿色轮胎胎面胶中的应用。结果表明:与牌号为VSL 4526-2HM的SSBR相比,牌号为VSL 2438-2HM,VSL PBR 4078和VSL PBR 4070的SSBR加工性能略差,其硫化胶的物理性能相对较好;末端改性SSBR(牌号为VSL PBR 4078和VSL PBR 4070)硫化胶的滚动阻力较小,抗湿滑性能较好。     

尿素对MCC-纳米SiO_2杂化材料形态、结构及应用的影响

利用微晶纤维素(MCC)易吸水溶胀的特点,将MCC在尿素水溶液中溶胀,控制吸附在MCC表面和内部尿素水膜的厚度。以此水膜为"微反应器",采用溶胶-凝胶工艺,以正硅酸乙酯为前驱体,在MCC表面和内部生成无机纳米SiO_2颗粒。红外光谱(IR)、热失重(TG)和扫描电镜分析(SEM)表明,纳米级别的SiO_2成功负载在微晶纤维素上。将MCC-纳米SiO_2杂化材料应用于胎面胶中,结果发现,MCC杂化改性后补强性能提高,硫化胶的压缩疲劳温升降低。     

偶联剂Si69原位改性白炭黑对SSBR胶料性能的影响

研究偶联剂Si69原位改性白炭黑对SSBR胶料性能的影响.结果表明,偶联剂Si69原位改性白炭黑可以降低SSBR混炼胶的门尼牯度.减弱混炼胶的Payne效应,改善混炼胶的加工性能;其在SSBR硫化胶中的分散度提高,且分散均匀,可以降低硫化胶的邵尔A型硬度,提高硫化胶的300%定伸应力.动态粘弹性能分析表明,偶联剂Si69原位改性白炭黑可降低60℃下、多次应变及大应变、宽频率范围内SSBR硫化胶的滞后损失.动态热力学分析表明,偶联剂Si69原位改性白炭黑可以提高SSBR硫化胶在0℃左右的损耗因子,从而提高胶料的抗湿滑性能.     

不同厂家SBR对高性能乘用轮胎胎面胶性能的影响

研究不同厂家溶聚丁苯橡胶(SSBR)、乳聚丁苯橡胶(ESBR)生胶和混炼胶的加工性能,并对胶料的硫化特性、物理性能、耐磨性能、抗湿滑性能和滚动阻力进行对比。结果表明,与ESBR相比,SSBR生胶及其混炼胶的加工性能相差不大,但均较难加工;SSBR胶料的硫化特性、物理性能满足轮胎加工及使用性能要求。LAT100磨耗试验结果表明,与ESBR相比,SSBR硫化胶的耐磨性能降低,抗湿滑性能提高,滚动阻力增大。     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009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、环氧树脂、不饱和聚酯树脂)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。     

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.     

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.     

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.