溶聚丁苯橡胶2557-A的基本性能

对中国石油独山子石化公司生产的溶聚丁苯橡胶(SSBR)2557-A的基本性能进行了研究,并与SSBR T 2530、5025-1以及乳聚丁苯橡胶(ESBR)1712的性能进行了对比。结果表明,相对于ES-BR 1712和SSBR T 2530,SSBR 2557-A的分子量分布较窄,乙烯基含量高;2557-A与SSBR 5025-1的微观结构基本一致;2557-A的拉伸强度和定伸应力均比1712和5025-1低;同1712和T 2530相比,2557-A和5025-1的硬度较高,回弹性很低,压缩生热较低;2557-A的耐磨耗性能低于1712和T2530;相对于1712,2557-A的热氧老化性能较好;2557-A具有优良的抗湿滑性能,滚动阻力较小。     

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。     

国产溶聚丁苯橡胶T2000 R的微观结构及基本性能

采用傅里叶变换红外光谱分析、凝胶渗透色谱-激光光散射-自动黏度在线检测仪、动态力学性能分析及差示扫描量热仪等手段对国产溶聚丁苯橡胶(SSBR-T2000 R)的微观结构及其基本性能进行了分析与表征,并与乳聚丁苯橡胶(ESBR-1502)作了对比。结果表明,与ESBR-1502相比,SSBR-T2000 R具有分子量分布窄、数均分子量较高、重均分子量明显低、支化度低的特点;其链结构中顺式-1,4-结构含量高、反式-1,4-结构、1,2-结构含量低;热稳定性高于ESBR-1502;玻璃化转变温度比ESBR-1502低,说明其具有优异的低温性能;高弹态动态模量较低,但其动态损耗因子和动态生热低于ESBR-1502;其硫化特性为焦烧时间较长,而正硫化时间较短;用密炼机加工胶料,SSBR-T2000 R的耐屈挠龟裂性优于ESBR-1502,且压缩生热较低。     

溶聚丁苯橡胶T2530基本性能的研究

探讨国产溶聚丁苯橡胶(SSBR)T2530的基本性能.结果表明,与乳聚丁苯橡胶(ESBR)1712E和1712相比,SSBR生胶的重均相对分子质量略小,数均相对分子质量稍大,相对分子质量分布较窄,纯胶含量较高;混炼胶的门尼粘度较高,硫化速度较快,焦烧时间略有缩短,但加工工艺性能差别不大;硫化胶的300%定伸应力和拉伸强度略低(适当调整炭黑用量可使300%定伸应力达到ESBR的水平),弹性较好,滚动阻力较低.     

SSBR2530在轮胎胎面胶中的应用

研究溶聚丁苯橡胶(SSBR)2530等量代替乳聚丁苯橡胶(ESBR)1712在轮胎胎面胶中的应用.结果表明,与ESBR1712胶料相比,SSBR2530胶料具有较好的耐磨和耐屈挠疲劳性能,并且生热较低.采用SSBR2530的成品轮胎与采用ESBR的成品轮胎相比,胎面胶物理性能相似,经济效益显著.     

国产溶聚丁苯橡胶T 2000 R的基本加工性能

通过开炼机、密炼机、橡胶加工分析仪、毛细管流变仪考察了国产溶聚丁苯橡胶(SSBR,牌号为T 2000 R)的基本加工性能,并与乳聚丁苯橡胶(ESBR,牌号为1502)进行了比较分析。结果表明,当开炼机辊筒温度控制在35~50℃,且前辊温度稍低于后辊温度,缩小辊距时,SSBR-T 2000 R包辊良好;为使SSBR-T 2000 R的密炼机混炼达到良好效果,密炼机温度开始应控制在60~80℃,且需采用增强剂或生胶分批加入的混炼工艺;与ESBR-1502相比,在较低温度(小于77℃)、低剪切频率(小于30 s-1)的条件下,如混炼、压延工艺,SSBR-T 2000 R混炼胶的剪切黏度和剪切模量较低,具有良好的加工性能;在挤出工艺中,SSBR-T 2000 R的剪切黏度较ESBR-1502稍高,应提高其加工温度,以100~130℃为宜,可使挤出物外观光滑。     

SSBR2530在载重斜交轮胎胎体配方中的应用

采用溶聚丁苯橡胶(SSBR)2530等量替代乳聚丁苯橡胶(ESBR)1712用于载重斜交轮胎胎体配方.结果表明,与ESBR1712胶料相比,SSBR2530胶料的硫化速度稍快,焦烧时间、硬度、强伸性能、撕裂强度和耐老化性能相当,压缩生热减小,粘合强度提高,加工性能明显改善.采用SSBR2530的成品轮胎耐久性能和帘布层间粘合强度均有所提高.     

炭黑对SSBR-T2000R屈挠疲劳的影响

通过改变炭黑的种类及用量,考察了炭黑粒径、结构度、用量对SSBR-T2000R屈挠性能及断面形貌的影响,并与乳聚丁苯橡胶ESBR-1502作了对比。结果表明,炭黑粒径对SSBR-T2000R屈挠性能有一定影响,粒径太小,炭黑对橡胶分子的吸附力大,使得承受应力的橡胶链段不能很快地通过分子运动产生应力松弛;粒径太大,对SSBR-T2000R硫化胶的补强作用差,强度低,屈挠疲劳性能降低。结构度对SSBR-T2000R屈挠性能的影响比ESRB-1502大。结构度高,SSBR-T2000R屈挠断面较不平整。SSBR-T2000R硫化胶的屈挠疲劳寿命随着炭黑用量的增多先增大后减小,炭黑用量在15份左右时硫化胶的耐屈挠性能最好;炭黑对SSBR-T2000R的补强效果高于对ESBR-1502的,从而使SSBR-T2000R的耐屈挠性能提高较快。     

充油溶聚丁苯橡胶2564 A的微观结构与性能

研究了溶聚丁苯橡胶(SSBR,牌号为2564 A)的微观结构与性能,并与牌号为5025-2的SSBR及乳聚丁苯橡胶(ESBR,牌号为1712)进行了对比。结果表明,与ESBR 1712相比,SSBR 2564 A生胶的数均分子量和重均分子量大,分子量分布窄,乙烯基和顺式结构含量高、反式结构含量低,混炼胶的硫化速率慢,硫化胶的物理机械性能略差,耐老化性能、压缩生热性能及炭黑分散性优;与SSBR 5025-2相比,SSBR 2564 A生胶的数均分子量、重均分子量及分子量分布相当,乙烯基含量高,顺式结构含量略高,反式结构含量低,混炼胶的结合胶含量高,交联密度相当,硫化速率略快,硫化胶的物理机械性能相当,耐老化性能优,压缩生热性能及炭黑分散性相当。     

调节剂对连续聚合溶聚丁苯橡胶乙烯基含量的调节

在连续聚合工艺条件下,采用调节剂四氢呋喃(THF)和复合调节剂对溶聚丁苯橡胶(SSBR)的乙烯基含量进行调节.结果表明,SSBR的乙烯基含量与THF/n-BuLi的相关性不强,而与THF的用量呈现较好的线性相关;与THF调节体系相比,复合调节体系对乙烯基结构的调节能力更强;连续聚合的SSBR相对分子质量分布宽,综合性能优于间歇聚合产品,其中高苯乙烯基和高乙烯基SSBR具有较高的抗湿滑性能.     

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。