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CR混炼过程中焦烧性能的研究 总被引:1,自引:2,他引:1
测试了CR在较宽混炼温度 ( 110~ 160℃ )和转子转速 ( 4 0~ 10 0r·min- 1 )范围内的混炼焦烧时间ts 和动态硫化指数Δt以及相应温度范围的门尼焦烧性能 (t5和Δt30 ) ,指出门尼焦烧性能不能真正反映混炼胶在实际加工过程中的焦烧特性。根据试验数据 ,拟合了CR的混炼焦烧性能与混炼温度或转子转速的关系及关系模型 ,从橡胶力化学反应的角度解释了温度和转子转速对CR混炼焦烧性能的影响趋势 ,并在此基础上对该模型进行了验证。方差、回归分析结果表明 ,该模型可以很好地表征CR混炼焦烧性能与混炼温度和转子转速之间的关系 ,在试验范围内 ,转子转速对CR混炼焦烧性能的影响比温度大 ,且两者间存在一定的交互作用。 相似文献
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研究停放时间对帘布胶和垫胶门尼粘度、门尼焦烧时间和硫化特性的影响。结果表明:随着停放时间的延长,帘布胶和垫胶的门尼粘度呈增大趋势,门尼焦烧时间先延长后缩短;帘布胶的最小转矩先增大后趋于平稳,t10呈延长趋势,t90变化不大;垫胶的最大转矩总体增大,最小转矩、t10和t90变化不大;帘布胶半成品的门尼粘度总体增大,门尼焦烧时间先缩短后延长,最小转矩略有增大,t10呈延长趋势,t90变化不大。帘布胶合理的停放时间在4 d以内,半成品应尽量缩短停放时间,以保证胶料性能稳定。 相似文献
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研究了密炼机再生工艺对废旧轮胎胶粉再生效果的影响。对再生橡胶的交联密度、溶胶含量、门尼黏度、物理机械性能和动态力学性能进行了分析。结果表明,溶胶含量随着脱硫温度的升高而逐渐增大;交联密度随着脱硫温度的升高而逐渐降低;根据horikx理论分析表明高混脱硫再生工艺再生过程中化学键的断裂以交联键断裂为主。再生胶的焦烧时间(ts 1)和再硫化时间(t9 0)随着脱硫温度的升高均呈现逐渐增大的趋势,拉伸强度随脱硫温度的增加逐渐降低。随脱硫时间的增加,再生胶硫化胶的拉伸强度略有降低,拉断伸长率变化不大。 相似文献
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根据普通密炼机一段混炼工艺和密炼结合开炼机低温混炼工艺,通过硫化特性、门尼黏度、Payne效应、基本力学性能及耐疲劳性能和耐磨耗性能等测试,研究了密炼机转子转速和开炼机薄通次数对胎面胶结构与性能的影响。结果表明,改变密炼机转子转速对硫化胶的耐疲劳性能和耐磨耗性能影响较大,随着转子转速的增加,胶料的疲劳寿命先下降后提高、耐磨耗性能逐渐上升;改变薄通次数对门尼黏度、Payne效应和基本力学性能影响较大,但对疲劳寿命和耐磨耗性能的影响不明显,薄通15次胶料的门尼黏度、Payne效应和基本力学性能明显下降;密炼结合开炼机低温薄通工艺的混炼效果优于普通密炼机一段混炼工艺的混炼效果。 相似文献
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通过与俄罗斯丁戊橡胶和BR对比 ,研究了国产新型稀土丁戊橡胶 (Nd BIR)的加工性能、未硫化胶性能和硫化胶物理性能 ,并探讨了Nd BIR在轮胎胎面胶中的应用。结果表明 ,Nd BIR混炼包辊性好 ,混炼功耗低 ,混炼胶片表面光滑平整 ;胶料硫化速度快 ,硫化曲线平坦 ,门尼焦烧时间长 ;硫化胶撕裂强度高 ,耐疲劳、耐磨耗和耐老化性能好 ,压缩生热低 ,低温性能极佳。NR/Nd BIR(并用比 70 /3 0和 5 0 /5 0 )并用体系胎面胶硫化速度快 ,焦烧时间长 ;硫化胶强伸性能好 ,耐磨、耐老化、耐疲劳和抗湿滑等性能满足轮胎胎面要求。Nd BIR用于轮胎胎面胶中是可行的 相似文献
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M. S. J. Simmonds W. M. Blaney F. Delle Monache M. Marquina Mac-Quhae G. B. Marini Bettolo 《Journal of chemical ecology》1985,11(12):1593-1599
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. 相似文献
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Cheng-Le Zhao Shane Porzio Alan Smith Haiyan Ge H. T. Davis L. E. Scriven 《Journal of Coatings Technology and Research》2006,3(2):109-115
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. 相似文献
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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. 相似文献
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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. 相似文献
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中蓝晨光化工研究院有限公司《塑料工业》编辑部 《塑料工业》2009,37(3)
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. 相似文献
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中蓝晨光化工研究院《塑料工业》编辑部 《塑料工业》2007,35(3):1-25,67
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。 相似文献