影响ACM／FKM硫化胶耐热老化性能的配方因素

研究了共混比、炭黑品种及用量、软化剂和防老剂种类等配方因素对丙烯酸酯橡胶（ACM）／氟橡胶（FKM）硫化胶耐热老化性能的影响。结果表明,经180℃×48h热老化后,ACM／FKM硫化胶的力学性能保持率随ACM用量的增加而降低;加入0～50质量份炭黑补强的硫化胶耐热老化性能随炭黑用量增加而提高;使用软化剂硅油的硫化胶的耐热老化性能较好;添加防老剂可提高共混硫化胶的耐热老化性能,其中防老剂RD和A效果较好。     

氯化丁基橡胶和氯丁橡胶的并用研究

本文通过试验主要研究了并用比例、硫化体系、炭黑品种及用量等因素对CIIR/CR并用胶物理机械性能、耐老化性能及耐臭氧老化性能等的影响。结果发现在CIIR/CR并用胶中随CIIR用量比例的增加,其硫化胶的扯断伸长率会随之提高。CIIR的加入对会有效改善CR的耐老化性能及耐臭氧老化性能。炭黑N550在用量为40~50份时,CIIR/CR硫化胶物理机械性能相对较好。     

硫化体系对CR/CIIR共混硫化胶性能的影响

研究了ZnO/S硫化体系、TCY/树脂复合硫化体系、Pb3O4/树脂复合硫化体系对CR/CIIR共混胶硫化特性、物理机械性能、耐热老化性能、耐油性能的影响。结果表明:采用ZnO/S硫化体系,共混胶的硫化速度较快,转矩较高;采用3种硫化体系的共混胶力学性能相当,而采用TCY/树脂复合硫化体系硫化的共混胶老化后力学性能保持率比ZnO/S/有机促进剂硫化体系高;采用ZnO/S/有机促进剂硫化体系的共混硫化胶耐油性能稍好。     

炭黑填充IIR胶料耐热老化性能的研究

研究了不同硫化体系以及其它配方因素对丁基硫化胶耐热老化性能的影响。以硫化胶老化后的力学性能保持率作为评价胶料耐热老化性能的参数。研究结果表明 :经过 160℃× 2 4h热空气老化后 ,树脂硫化丁基胶的力学性能保持率比硫黄硫化胶和给硫体硫化胶高 ;炭黑的品种、防老剂的种类、操作油的品种、Zn0的用量对丁基硫化胶的力学性能和耐热老化性能都有一定影响     

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。     

聚醚型聚氨酯橡胶／氯丁橡胶共混物性能的研究

研究了聚醚型聚氨酯橡胶/氯丁橡胶共混物复合交联体系及其对共混硫化胶物理机械性能的影响;探讨了聚氨酯橡胶/氯丁橡胶共混胶料的硫化特性,共混硫化胶的力学性能、耐热老化性能和动态力学性能.结果表明:硫黄/MgO体系能够很好地硫化PUR/CR共混胶;当共混胶中PUR用量在0～100份范围内,共混胶的焦烧时间和正硫化时间均先减小后增加,最小转距和最大转距都降低;拉伸强度、撕裂强度和硬度均随PUR用量的增加而增加.拉断伸长率在PUR用量为40份时最大;共混硫化胶的耐热老化性能随着PUR用量的增加而增加,其拉仲强度保持率和拉断伸长率保持率呈上升趋势;动态力学研究表明,PUR和CR有很好的相容性,玻璃化温度随着PUR用量的增加而降低.     

HNBR/CR并用比对共混胶性能的影响

探讨了HNBR/CR并用比对共混胶加工性能、力学性能、耐热老化性能和耐油性能的影响。结果表明,随CR用量的增加,共混胶的硫化效率提高,加工性能逐渐改善,动态生热量降低,力学强度和耐油性能都有所下降。当HNBR/CR并用比大于70/30时,共混胶的拉伸强度和热空气老化后的性能保持率依然较高,且耐油性能优良,可满足一些耐油、耐热场合对胶料的基本性能要求。当并用比小于60/40时,共混胶的力学性能、耐油性能和耐热老化性能下降较为严重。     

硫化体系对CR／SBR共混胶性能的影响

探讨了给硫体和TCY／给硫体2种不同硫化体系对CR／SBR共混胶硫化特性、硫化橡胶力学性能和耐热老化性能的影响。结果表明：含DTDM的共混胶焦烧时间较长。正硫化时间较短,硫化特性较好。采用TCY／给硫体复合硫化体系且随着TCY用量的增加,CR／SBR硫化橡胶拉伸强度先增大后减小,TCY用量为1份拉伸强度达到最大值（23．0MPa）。2种不同硫化体系的硫化橡胶耐热老化性能都较好,老化后拉伸强度保持率在100％左右,拉断伸长率保持率也在70％左右。     

炭黑对ACM硫化胶性能的影响

研究了炭黑对ACM胶料的硫化特性、硫化胶力学性能、耐油性能以及耐热老化性能的影响.结果表明,在TCY/S用量分别为1.5份/0.3份,炭黑N220/N330用量分别为25份/25份时,ACM混炼胶具有较好的硫化特性,硫化胶具有较好的力学性能、耐油性能以及耐热老化性能.     

炭黑/酚醛树脂增强丁腈橡胶/氯丁橡胶并用胶的性能

采用炭黑与酚醛树脂复合增强体系对丁腈橡胶/氯丁橡胶(NBR/CR)并用胶进行增强,研究了其用量对并用胶硫化特性、力学性能及动态力学性能的影响。结果表明,保持炭黑与树脂总量不变,用酚醛树脂代替部分炭黑后,NBR/CR并用胶的加工性能提高,硫化速率降低,硫化时间延长。当酚醛树脂代替10份炭黑时,并用硫化胶的拉伸强度最大,说明炭黑与树脂具有协同作用。树脂用量相同时,随着炭黑用量的增加,NBR/CR并用硫化胶的Payne效应增强。     

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。