ESBR硫化胶交联结构及动态粘弹性在拉伸疲劳过程中的变化

研究炭黑和白炭黑填充乳聚丁苯橡胶硫化胶拉伸疲劳过程中交联结构和动态粘弹性的变化。结果表明,炭黑填充胶料的拉伸性能在拉伸疲劳次数低于50万次时下降明显,而白炭黑填充胶料在50万～100万次之间下降幅度较大;随着拉伸疲劳次数的增加,两种胶料的交联密度均减小;拉伸疲劳次数达到200万次时,炭黑填充胶料的tanδ峰宽明显增大,而白炭黑填充胶料在拉伸疲劳次数50万次以上tanδ峰就明显增高、增宽;炭黑填充胶料疲劳后高弹态的tanδ变化不大,而白炭黑填充胶料tanδ显著增大;白炭黑填充胶料的Payne效应较炭黑填充胶料大,且拉伸疲劳后Payne效应明显减小。     

白炭黑在NR/BR/SSBR并用胶中的应用

研究了白炭黑／炭黑填充NR／BR／SSBR并用胶的物理性能，用橡胶加工分析仪(RPA2000)分析并用胶硫化性能和动态粘弹性的变化规律。结果表明，炭黑和白炭黑总量固定．白炭黑的用量增大时，并用胶的物理性能略有下降，固特里奇压缩疲劳性能改善，并用胶的硫化速度减缓，且t90和t10的变化与白炭黑的用量呈线性关系；60℃的tanδ值随白炭黑用量增大而呈下降趋势，即硫化胶的滚动阻力降低。     

白炭黑Z125对NR和S-SBR硫化胶性能的影响

探讨了白炭黑Z125用量对NR和S-SBR硫化胶性能的影响.结果表明:随Z125用量增大,NR和S-SBR两种硫化胶的物理机械性能得到明显改善,且分别在填充量为45 phr和60 phf时有较好的综合物理机械性能;与S-SBR硫化胶相反,NR硫化胶的耐疲劳破坏性随Z125用量增大明显降低;随屈挠次数的增加,NR硫化胶的割口尺寸单调增大,而S-SBR硫化肢的初始割口尺寸迅速增大,之后稍有升高;随Z125用量增大,NR和S-SBR硫化肢的损耗因子峰值(tan δmax)减小,0～70℃时,NR的损耗因子值(tan δ)和弹性模量(E')增大,S-SBR高于20℃时的tanδ艿值增加,E,基本呈增大趋势.     

白炭黑填充NR拉伸疲劳过程中介观结构及动态粘弹性的演变

通过改变白炭黑粒子的网络化程度,系统地研究了其填充天然橡胶在拉伸疲劳过程中的介观结构及动态粘弹性能。结果表明,硫化胶疲劳寿命与白炭黑粒子的网络化程度呈线性关系;疲劳试验后,硫化胶Payne效应的下降幅度与白炭黑粒子的网络化程度正相关;疲劳前试样的损耗因子tanδ达到峰值时所需应变高于疲劳后试样;tanδ随疲劳程度的增大而升高,疲劳前试样的E′值对温度的依赖性较强,填充50份白炭黑的NR橡胶E′下降过程可分为2个阶段;白炭黑粒子在疲劳过程中出现一定程度的团聚现象。     

硫化时间对绿色轮胎胎面胶交联网络结构与性能的影响

针对以溶聚丁苯橡胶(SSBR)/顺丁橡胶(BR)并用胶为主体材料的绿色轮胎胎面胶,研究在不同硫化时间下未填充白炭黑的SSBR/BR并用胶(简称未填充白炭黑体系胶料)及填充白炭黑的SSBR/BR并用胶(简称填充白炭黑体系胶料)形成的交联网络结构与性能变化。结果表明:对于未填充白炭黑体系胶料,随着硫化时间的延长,硫化胶的交联密度略有降低,硬度、定伸应力、拉伸强度和回弹值等变化不大,撕裂强度提高,拉断伸长率和耐伸张疲劳性能降低;对于填充白炭黑体系胶料,随着硫化时间的延长,硫化胶的填料网络结构化程度逐渐提高,交联密度略有增大,键能较低的多硫键减少,键能较高的单硫和双硫键增多,硫化胶的拉伸强度、回弹值、耐伸张疲劳性能和耐磨性能基本不变,生热和滚动阻力降低;未填充及填充白炭黑体系硫化胶的耐老化性能均随硫化时间的延长而逐渐提高,这表明以SSBR/BR并用胶为主体材料的胎面胶即使在高温下硫化较长时间,仍具有较好的性能。     

IIR/CIIR共混胶的动态力学性能

研究了共混比、硫化体系、增强剂、软化剂和硅烷偶联剂对IIR/CIIR共混胶动态力学性能的影响。结果表明,随CIIR用量增加,共混胶的储能模量(E')和损耗模量(E″)逐渐增加,而阻尼因子(tanδ)峰值逐渐减小,共混胶的玻璃化转变温度(Tg)向高温方向偏移;采用叔丁基酚醛树脂硫化的共混胶的E″比硫黄硫化的高,但tanδ峰值和Tg均低于后者;细粒子高结构炭黑N220填充的共混胶的E'和E″较高,tanδ峰值较低,而粗粒子半增强炭黑N754填充的共混胶的E'和E″较低,tanδ峰值较高;软化剂凡士林的加入,使共混胶的E'和E″降低,tanδ峰值增加,而且Tg向低温方向偏移;γ-氨基丙基三乙氧基硅烷增加了共混胶的E'和E″值,但tanδ峰值降低,Tg基本不变。     

白炭黑与溶聚丁苯橡胶的键接位置对白炭黑/炭黑/溶聚丁苯橡胶复合材料性能的影响

研究白炭黑/炭黑填充星形溶聚丁苯橡胶(SSBR)和分子链自由末端用硅氧烷基团封端改性星形SSBR(S-SSBR)的物理性能、动态力学性能和微观结构。结果表明:随着偶联剂用量(硅氧烷基团物质的量)的增大,星形SSBR复合材料的拉伸强度先增大后减小,S-SSBR复合材料的拉伸强度先减小后增大;星形SSBR和S-SSBR复合材料的300%定伸应力呈增大趋势,压缩疲劳温升降低,0℃下损耗因子(tanδ)增大,60℃下tanδ值减小。当复合材料中硅氧烷基团的物质的量相同时,与星形SSBR复合材料相比,S-SSBR复合材料定伸应力和0℃下tanδ值的增幅、压缩疲劳温升和60℃下tanδ值的降幅较大,填料的分散性较好。     

白炭黑在NR／BR／SSBR并用胶中的应用

研究了白炭黑／炭黑填充NR／BR／SSBR并用胶的物理性能，用橡胶加工分析仪(RPA2000)分析并用胶硫化性能和动态粘弹性的变化规律。结果表明，炭黑和白炭黑总量固定，白炭黑的用量增大时，并用胶的物理性能略有下降，固特里奇压缩疲劳性能改善，并用胶的硫化速度减缓，且t90和t10的变化与白炭黑的用量呈线性关系；60℃的tan8值随白炭黑用量增大则呈下降趋势，即硫化胶的滚动阻力降低。     

白炭黑填充溶聚丁苯橡胶并用胶复合材料的性能对比研究

对比研究白炭黑填充溶聚丁苯橡胶(SSBR)以及SSBR并用顺丁橡胶(BR)、异戊橡胶和反式1,4-聚异戊二烯(TPI)所制备复合材料的性能。结果表明:经偶联剂Si69改性的白炭黑填充的SSBR/BR并用胶在低温下的损耗因子(tanδ)最大,在60℃下的tanδ值最小,耐磨性能最好,抗切割性能最差;白炭黑填充的SSBR/TPI并用胶在60℃下的tanδ值最大。     

炭黑和白炭黑填充环氧化反式-1,4-聚异戊二烯硫化胶的性能研究

首次研究了炭黑和白炭黑对水相悬浮法合成环氧化反式-1,4-聚异戊二烯(ETPI)硫化胶性能的影响。结果表明,炭黑对ETPI硫化胶的正硫化时间影响不大,而白炭黑对ETPI硫化胶的正硫化时间有明显的延迟效应;炭黑和白炭黑使ETPI硫化胶的100%定伸强度和撕裂强度明显提高,白炭黑填充的ETPI比炭黑填充的撕裂强度提高的幅度更大,并且随着加入份数的增加而增大,断裂伸长率和回弹值逐渐降低,邵尔A硬度逐渐增大;动态力学性能(DMA)测试显示,对于水相悬浮法合成的ETPI硫化胶,炭黑和白炭黑使40℃以上tanδ峰值明显提高,有利于阻尼材料宽温域的要求,但0℃时tanδ值逐渐下降,抗湿滑性降低;60℃时tanδ值上升,滚动阻力提高,对轮胎胎面胶的使用不利。     

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.     

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.     

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。     

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.     

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.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Some Large Wood-Boring Beetles in Southeastern USA

Ethanol and α-pinene were tested as attractants for large wood-boring pine beetles in Alabama, Florida, Georgia, North Carolina, and South Carolina in 2002–2004. Multiple-funnel traps baited with (−)-α-pinene (released at about 2 g/d at 25–28°C) were attractive to the following Cerambycidae: Acanthocinus nodosus, A. obsoletus, Arhopalus rusticus nubilus, Asemum striatum, Monochamus titillator, Prionus pocularis, Xylotrechus integer, and X. sagittatus sagittatus. Buprestis lineata (Buprestidae), Alaus myops (Elateridae), and Hylobius pales and Pachylobius picivorus (Curculionidae) were also attracted to traps baited with (−)-α-pinene. In many locations, ethanol synergized attraction of the cerambycids Acanthocinus nodosus, A. obsoletus, Arhopalus r. nubilus, Monochamus titillator, and Xylotrechus s. sagittatus (but not Asemum striatum, Prionus pocularis, or Xylotrechus integer) to traps baited with (−)-α-pinene. Similarly, attraction of Alaus myops, Hylobius pales, and Pachylobius picivorus (but not Buprestis lineata) to traps baited with (−)-α-pinene was synergized by ethanol. These results provide support for the use of traps baited with ethanol and (−)-α-pinene to detect and monitor common large wood-boring beetles from the southeastern region of the USA at ports-of-entry in other countries, as well as forested areas in the USA.