TPI/HVBR/NR共混物的性能

对高反式-1，4-聚异戊二烯（TPI）/高乙烯基聚丁二烯橡胶（HVBR）/NR共混物的综合物理性能和动态力学性能进行研究。结果表明，在TPI/HVBR/NR共混物中，NR用量为70份，HVBR用量为10～20份，可使胶料具有较低的滚动阻力和生热，且胶料的抗湿滑性明显改善。当HVBR用量为20份时，表征胶料抗湿滑性能的0℃时的tanδ值提高42.2%，而表征滚动阻力和生热的60和80℃时的tanδ值进一步降低；NR用量为70～50份，TPI用量为10～25份和HVBR用量为20～35份的TPI/HVBR/NR共混物不仅具有较好的综合物理性能，而且具有较低滚动阻力和较高抗湿滑性，是一种较为理想的胎面胶配合。     

TPI/HVBR/SBR共混物的性能

对高反式－1，4－聚异戊二烯（TPI）／高乙烯基聚丁二烯橡胶（HVBR）／SBR共混物的综合物理性能和动态力学性能进行研究。结果表明，共混物中TPI／HVBR／SBR并用比为10／20／70时，共混物具有较低的滚动阻力和动态生热及优异的耐屈挠疲劳性和耐磨性，与TPI／SBR（并用比为30／70）比较，其抗湿滑性提高（0℃时的tanδ值增大76．3％）。在SBR用量为70－50份，TPI用量为15－25份和HVBR用量为15－35份范围内，共混物具有良好的综合性能，滚动阻力和抗湿滑性获得平衡，同时具有优异的耐磨性和耐屈挠疲劳性，是高性能胎面胶料的较理想配合。     

TPI/HVBR共混物用于胎面胶的研究

在传统的胎面胶配方NR／SBR1500（并用此为60／40）和SBR1712／SBR1500（并用比为60／40）的基础上，采用高反式－1，4－聚异成二烯（TPI）和／或高乙烯基聚丁二烯橡胶（HVBR）取代或部分取代SBR1500，研究共混物的物理性能和动态粘弹性。结果表明，添加了TPI和HVBR的胎面胶，其力学性性能可满足使用要求，定伸应力和抗屈挠疲劳性较大提高，滚动阻力和动态生势明显降低，而抗湿滑性仍有较高的保持率，达到了滚动阻力和抗湿润性能的良好兼备。相对而言，NR／TPI／HVBR并用胎面胶具有量的滚动阻力和生热，而SBR／TPI／HVBR并用胎面胶具有更好的抗湿滑性、抗屈挠疲劳性和耐磨性。     

高性能子午线轮胎胎面胶的开发

采用充油SBR1721和低滞后炭黑DZ-13开发高性能子午线轮胎胎面胶配方,并试制185/60R14 82H轿车子午线轮胎。结果表明,试验配方胶料的基本物理性能与生产配方相差不大;损耗因子(tanδ)在40~100℃内较小,胶料的滚动阻力和生热降低,tanδ在-15~ 15℃内较大,胶料的抗冰滑和抗湿滑性能优异;试验轮胎在冰滑和湿滑路面上的抓着力较大,行驶时牵引力增大,制动距离明显缩短,同时滞后损失和生热降低,即轮胎的抗滑性能、滚动阻力和耐磨性能获得很好的平衡。     

SSBR改善胎面胶动态力学性能的研究

考察了不同种类和不同用量的SSBR在轮胎胎面胶中的应用,研究了NR／SSBR硫化橡胶的物理机械性能和动态力学性能。结果表明：天然橡胶与新型溶聚丁苯橡胶SSBR2并用比为70／30时。硫化橡胶具有优异的动态力学性能和较低压缩生热;DMA测试结果表明：随着SSBR2的加入,硫化橡胶0℃时的tanδ值逐渐增大,60℃时的tanδ值减小。实验表明：加入适量SSBR2能够满足胎面胶基本物理性能要求,而且具有较低生热和较好的抗湿滑性。     

钼系高乙烯基聚丁二烯橡胶用于半钢轮胎胎面的研究

采用质轻、优异耐老化性、低生热和高抗湿滑性的高乙烯基聚丁二烯橡胶(HVBR)部分替代不同结构含量的SSBR用于轮胎应用配方。高性能成品轮胎初步测试结果表明,HVBR的取代量为15%~30%时,胎面胶的耐磨性、低生热和抗湿滑性等综合性能最佳,操作油的加入可以很好地改善胶料的加工性,提高炭黑分散性、耐疲劳性、耐低温性和回弹性,但是耐磨性变差。当HVBR代替15份SSBR2550时,轮胎抗湿滑性与滚动阻力与现有轮胎相当,且耐老化性和耐磨性均略高于原配方胎。     

NR/BR/NBR并用胶的结构与性能

研究了NR／BR／NBR并用胶的结构与性能。透射电子显微镜分析显示，随着NBR用量的增大，炭黑的分散趋于均匀；NR／BR／NBR并用胶出现两个玻璃化温度，在O℃时的tanδ值增幅较大，而在65和80℃时的tanδ值变化不大；并用胶物理性能变化不大。通过调节NBR用量可获得抗湿滑性能较好、滚动阻力和生热小的胎面胶。     

NR/SBR/BR共混胎面胶料动态力学性能及生热特性研究

利用动态力学分析技术,研究了8种胎面胶料配方的滚动阻力、湿抓着性及生热率,实验结果表明：SBR的滞后损失大,生热多,BR的抗湿滑性差一些,NR/SBR/BR的并用比为60/20/20有良好的湿抓着性、低的滚动阻力和生热率,炭黑N121比N115的滚动阻力和生热率都小,湿抓着性良好.实验结果一方面为轮胎胎面胶料配方提供参考,另一方面为轮胎温度场的研究提供物性参数生热率.     

高乙烯基聚丁二烯橡胶双羧酸型钠离聚体的阻尼性能

将高乙烯基聚丁二烯橡胶(HVBR)与马来酸酐接枝改性后,与氢氧化钠络合制备了HVBR双羧酸型钠离聚体。结果表明,HVBR接枝共聚物断裂表面出现许多裂痕,在动态力学性能测试中发生断裂,而HVBR钠离聚体断裂表面出现许多相连的凸起结构。与HVBR相比,HVBR钠离聚体具有较好的抗湿滑性、低生热和低滚动阻力,拓宽了有效阻尼温域,更接近于室温。     

溶聚丁苯橡胶2557A的结构与性能研究

研究溶聚丁苯橡胶(SSBR)2557A的结构和性能,探讨其对轮胎胎面胶抗湿滑性能和滚动阻力的影响,并与乳聚丁苯橡胶(ESBR)1712E进行对比。结果表明:与ESBR1712E相比,SSBR2557A的乙烯基含量高,数均和重均相对分子质量大,相对分子质量分布指数小;混炼胶的焦烧时间长,硫化速度稍慢;硫化胶的邵尔A型硬度和定伸应力稍高,拉断伸长率减小,压缩生热和压缩永久变形较低,其他物理性能差别不大,不同应变下的剪切弹性模量、剪切损耗模量和损耗因子(tanδ)均较小,0℃下的tanδ值较大,60℃下的tanδ值较小。采用SSBR2557A的胎面胶在抗湿滑性能和滚动阻力方面可达到较好的平衡。     

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.     

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.     

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。     

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.