改性热解炭黑的结构表征及其在丁苯橡胶中的应用

对比研究热解炭黑和改性热解炭黑的结构和性能及其在丁苯橡胶(SBR)中的应用。热解炭黑经浓硝酸和浓氢氟酸依次处理后得到改性热解炭黑,与热解炭黑相比,改性热解炭黑的DBP吸油值、挥发分含量增大,BET比表面积减小,二次结构粒径分布变宽、变大,表面羟基消失,羧基等极性基团增加不明显。与热解炭黑补强SBR相比,改性热解炭黑补强SBR混炼胶的门尼粘度增大,加工性能下降,焦烧时间延长,硫化速率减小;硫化胶的定伸应力增大20%~30%,拉伸强度增大10%,耐磨性能提高,压缩生热减小。     

连续法热解炭黑的性能及其在丁苯橡胶中的应用

研究连续法热解炭黑的性能及其在丁苯橡胶(SBR)中的应用。结果表明:热解炭黑是多种填料的混合物,为半补强炭黑,表面活性较低;与炭黑N660填充SBR混炼胶相比,热解炭黑填充SBR混炼胶的门尼粘度增大,焦烧时间缩短,硫化速率略有提高,交联密度有所下降;与炭黑N660填充SBR硫化胶相比,热解炭黑填充SBR硫化胶的拉伸强度、拉断伸长率和撕裂强度增大,硬度变化不大,定伸应力减小,动态生热性能和耐磨性能略有下降。     

热解炭黑的研磨和偶联改性及其对丁苯橡胶的补强作用研究

采用研磨和偶联剂乙烯基三乙氧基硅烷（VTEO）对热解炭黑（CBp）进行改性处理,研究研磨改性CBp和VTEO改性CBp补强对丁苯橡胶（SBR）胶料性能的影响。结果表明：随着研磨时间的延长,CBp粒径减小,与橡胶大分子链的相互作用增强,研磨改性CBp补强SBR胶料的门尼粘度和Fmax－FL增大,硫化胶的物理性能提高;VTEO改性使CBp补强SBR胶料的t10延长,加工安全性提高,当采用1份VTEO改性50份CBp时,硫化胶的拉伸强度提高1.6 MPa。     

废轮胎热解再生炭黑表面活性

为克服废轮胎常压热解再生炭黑(PC)表面碳质沉积物过多、表面活性差和不适于橡胶补强应用等缺点,本文以反相气相色谱法为分析手段,分别通过硝酸酸洗和硬脂酸-硝酸酸洗等方法改性处理PC,以期改善PC结构和提高其表面性能,继而改善PC填充天然橡胶硫化胶的机械性能.系统地考察了未改性PC以及硝酸酸洗改性热解炭黑(WPC)、硬脂酸-硝酸酸洗改性热解炭黑(SWPC)表面能色散分量、极性分量、热力学函数变化以及炭黑表面不同活性点的能量分布情况,并考察了改性处理对热解炭黑填充天然橡胶硫化胶机械性能的影响.实验结果表明,硝酸酸洗改性在炭黑表面引入较多的羟基和羧基等官能团,导致其表面能过高,不利于天然橡胶补强.而在硝酸酸洗基础上,通过加入硬脂酸再改性后,可以减少炭黑颗粒之间的团聚,降低表面能,改善炭黑在硫化胶中的分散性.通过硫化胶机械性能测试实验发现,与PC和WPC相比,填充SWPC的天然橡胶具有较高的拉伸强度、扯断伸长率、300%定伸应力,能基本达到半补强炭黑的应用标准.     

炭黑与白炭黑补强溶聚丁苯橡胶和乳聚丁苯橡胶胎面胶性能的对比研究

对比研究采用相同体积分数的炭黑和白炭黑分别补强溶聚丁苯橡胶(SSBR)和乳聚丁苯橡胶(ESBR)胎面胶的性能。试验结果表明:与炭黑填充丁苯橡胶(SBR)胶料相比,经偶联剂Si69(用量为白炭黑用量的8%)热处理的白炭黑填充SBR胶料的分散性改善,硫化胶的300%定伸应力增大,拉断伸长率减小,抗湿滑性能提高,滚动阻力和动态生热降低,耐磨性能和抗切割性能较差。     

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.     

白炭黑/热解炭黑并用对胎侧胶料性能的影响

测试了热解炭黑的部分理化性质,研究了热解炭黑的主要组成,粒径分布以及白炭黑/热解炭黑不同并用比对胎侧胶性能的影响。结果表明,热解炭黑由大部分炭黑、少量无机填料和微量未裂解的橡胶分子链组成;其粒径属于微米级,且分布范围宽;应用在胎侧胶中时,随着白炭黑/热解炭黑并用比的减小,硫化胶的动态性能变化明显,首先是压缩生热减少,硫化胶的tanδ先减小后增大,Payne效应依次减小;随着白炭黑/热解炭黑并用比的减小,大形变下硫化胶的拉伸强度有所下降,但100%定伸应力、300%定伸应力和补强因子(300%定伸应力/100%定伸应力)没有明显下降并有上升趋势。当白炭黑/热解炭黑并用比为45/15时,胎侧胶混炼胶具有较好的加工性能,硫化胶具有优良的动态力学性能,较小的损耗因子,且物理机械性能变化不大。     

二苯基硅烷改性白炭黑对SBR性能的影响研究

以二苯基硅烷作改性剂制备了改性白炭黑，研究了二苯基硅烷用量对白炭黑补强SBR性能的影响。结果表明，加入二苯基硅烷后，SBR胶料焦烧时间、工艺正硫化时间及最高转矩均明显增大，最低转矩逐渐减小；加入二苯基硅烷对SBR硫化胶力学性能有一定的改善作用；当用量为2份时，SBR硫化胶综合力学性能较好。随着二苯基硅烷用量的增大，SBR硫化胶0℃损耗因子tanδ略有增大，60℃损耗因子tanδ略有减小；白炭黑在SBR中的附聚体尺寸明显降低；当其用量为1份时，白炭黑附聚体尺寸达到最小值9.46μm。     

白炭黑对炭黑／丁苯橡胶复合材料耐疲劳性能的影响

研究白炭黑对炭黑/丁苯橡胶(SBR)复合材料耐疲劳性能的影响。结果表明:与炭黑/SBR复合材料相比,白炭黑/炭黑/SBR胶料的t10延长,交联密度下降,硫化胶的100%和300%定伸应力减小,拉断伸长率增大;在相同应变下,SBR复合材料的疲劳寿命延长,疲劳裂纹增长速率对撕裂能的敏感程度差别不大;白炭黑粒径越小,比表面积越大,结构度越低,对SBR复合材料的耐疲劳性能越有利。     

废轮胎热解炭黑/炭黑N550并用对丁苯橡胶性能的影响

表征了废轮胎热解炭黑(CBp)与炭黑N550的差异,并将两者并用填充到SBR中,考察其对SBR各项性能的影响。结果表明,CBp中灰分含量远高于炭黑N550,统计吸附比表面积相近,但结构度低。随着CBp用量的增大,胶料焦烧时间和正硫化时间明显缩短,挤出半成品表面变得粗糙,硫化胶拉伸性能、撕裂性能下降幅度很小,定伸应力下降,耐磨性变差;0℃tanδ值逐渐减小,60℃tanδ值变化不明显。     

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。