IIR/EPDM并用硫化胶压缩永久变形性能的研究

研究了IIR／EPDM的并用比例、炭黑品种与黑用量、硫黄用量、促进剂CZ用量对IIR／EPDM并用硫化胶压缩永久变形的影响。结果表明：IIR／EPDM并用比例为80／20时,硫化胶具有较好的综合力学性能;在所研究的填充补强体系中,ISAF能够赋予硫化胶较好的耐压缩性能,适宜用量为50份;IIR／EPDM并用硫化胶的压缩永久变形在硫黄用量为0．5－1．0份较好;在研究的范围内,促进剂CZ的用量对IIR／EPDM并用硫化胶的压缩永久变形影响不大。     

补强剂对CO/ECO共混硫化胶断裂行为的影响

采用CO/ECO不同并用比、不同补强剂和不同用量作为研究变量,研究了CO/ECO共混硫化胶的力学性能和共混硫化胶的拉伸断面形貌。结果表明,当CO/ECO共混比为50/50,采用白炭黑补强的共混硫化胶拉伸强度较高,拉断伸长率达到1000%以上,拉伸断面胶料有明显流动现象;采用N220炭黑补强的共混硫化胶拉伸强度达到16.5MPa,拉伸断面粗糙并有明显"瓣膜",共混胶的综合力学性能较优,并具有较好的加工性能。     

IIR/EPDM并用胶性能的研究

对IIR/EPDM并用胶性能进行试验研究。结果表明,在EPDM用量不超过30份时,随着EPDM用量的增大,IIR/EPDM并用胶的加工性能、焦烧时间和硫化速度变化不大;与IIR硫化胶相比,IIR/EPDM并用胶的交联密度减小,拉伸强度和拉断伸长率增大,撕裂强度略有提高,长期耐热老化性能相当,-10～ 25℃时的损耗因子小于IIR硫化胶,25～200℃时的损耗因子大于IIR硫化胶。     

软质炭黑并用在内胎再生胶中增强作用的比较

研究炭黑N550/N660并用对共混胶RIIR/IIR/EPDM/胶囊再生胶性能的影响.结果表明:随着炭黑N550/N660并用体系中N550用量的增加,共混胶的门尼黏度增加焦烧时间(t10)、正硫化时间(t90)均有所缩短,交联密度略有增加,硫化胶的100％、300％ 定伸应力增大,硬度和拉伸强度增大,断裂伸长率减小...     

炭黑对IIR/CIIR共混硫化胶压缩弹性模量的影响

研究了IIR／CIIR不同并用比和不同炭黑和用量以及软化剂品种和用量对IIR／CIIR共混硫化胶压缩弹性模量的影响。结果显示：当IIR／CIIR并用比为80／20，N220炭黑用量为80份时共混硫化胶有良好的压缩弹性模量，软化剂的加入会降低共混硫化胶的压缩弹性模量。     

影响IIR/CIIR共混硫化胶动态力学性能的因素

研究了IIR/CIIR井用比、补强剂品种和用量以及软化剂对IIR／CIIR共混硫化胶动态力学性能的影响。研究表明：IIR/CIIR井用比对共混硫化胶的动态力学性能有明显的影响，当IIR/CIIR的井用比为80／20时，综合力学性能比较好；炭黑品种和用量对共混硫化胶动态力学性能有显著的影响。组粒子炭黑使共混硫化胶的损耗因子tanδ峰值增大，随炭黑用量增大，tanδ峰值显著威小；软化剂也在一定程度上影响共混硫化胶的动态力学性能。     

EPDM/NR并用胶压缩永久变形的研究

研究了EPDM/NR并用比、配合剂、硫化体系、补强体系和EPDM预硫化工艺等对EPDM/NR并用胶高温条件下压缩永久变形的影响。结果表明,当EPDM用量介于70~80份之间时,并用胶压缩永久变形最大;EGDMA配合剂改性的EPDM/NR并用胶压缩永久变形最小,聚异丁烯改性的最大;过氧化物硫化体系的EPDM/NR并用胶压缩永久变形最小,硫黄硫化体系的最大;随炭黑类填料用量的增加,并用胶压缩永久变形先减小后增大,但随着无机类填料用量的增加而增加;填充快压出炭黑（N550）并采用EPDM预硫化工艺能有效降低并用胶压缩永久变形。     

DCP／MgO复合硫化体系的PUR／CR共混物硫化特性

采用硫化特性参数、溶胀指数和DSC谱图等表征了聚氨酯橡胶(PUR)/氯丁橡胶(CR)共混胶的共硫化性能,并研究了PUR/CR的共混比、补强体系与软化体系等对共混胶的硫化特性的影响.结果表明,采用过氧化二异丙苯/氧化镁(DCP/MgO)复合硫化体系,可以使PUR/CR共混胶达到共硫化;增加PUR和炭黑的用量,减少软化剂的用量,则共混胶料的转矩增大;增加PUR用量,可以加快共混胶料的硫化速度,其它因素对硫化速度的影响不明显.当PUR/CR共混比为20/80、DCP 3份、MgO 4份、炭黑N550 30份、软化剂聚异丁烯(PIB)5份时,共混硫化胶有较好的综合性能.     

硫黄硫化体系对IIR/EPDM共混胶力学性能的影响

研究IIR/EPDM体系中共混比、硫黄硫化体系对其共混胶性能的影响。结果表明 ,IIR与EPDM共混相容性较好 ,可以达到共硫化 ;IIR/EPDM共混比为 75 /2 5时共混胶性能最好 ;用传统硫化体系 (CV)、有效硫化体系 (EV)和半有效硫化体系 (SEV)都能得到性能较好的共混胶 ,其中以CV体系的硫化胶性能最好。     

IIR和HIIR的应用研究进展

简介IIR和卤化丁基橡胶(HIIR)的配合体系及并用共混体系.IIR的硫化体系主要包括硫黄、树脂和醌类硫化体系,HIIR还可采用氧化锌和金属硫化物等硫化体系,补强填充剂主要包括炭黑、白炭黑和煅烧高岭土等.IIR与EPDM的相容性和共硫化性较好,IIR并用部分EPDM可改善其耐热性能和抗氧化性能.HIIR中并用部分NR可提高其加工性能、生胶强度和硫化胶低温性能.CIIR与石油树脂、酚醛树脂或聚丙烯酸乙醇的共混物阻尼性能良好.     

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。