EPDM的压缩永久变形性能研究

研究了硫化体系、填充体系、增塑体系和硫化时间对EPDM高温下压缩永久变形的影响。实验结果表明：在硫黄、过氧化物、酚醛树脂3种硫化体系中,过氧化物配合助交联剂（TAIC）硫化的EP—DM压缩永久变形最小,硫磺硫化体系硫化胶则最大;胶料的压缩永久变形随着炭黑类填料用量的增加而降低,却随着无机类填料用量的增加而增加;填充具有高结构、适当粒径的炭黑（如N550）并适当延长硫化时间能有效降低EPDM的压缩永久变形。     

三元乙丙橡胶压缩永久变形的研究

研究了不同硫化体系、防老剂及试验温度对４种牌号的三元乙丙橡胶的压缩永久变形的影响。结果表明：采用过氧化物ＤＣＰ硫化体系硫化的三元乙丙橡胶ＥＳＰＲＥＮＥ５５３牌号硫化胶，可获得较低的压缩永久变形，且随试验温度的升高呈现近似线性增大的程度也较小；加入３份防老剂ＭＢ，可进一步降低其压缩永久变形。防老剂ＲＤ、防老剂２２４６及３０号机油均可使三元乙丙橡胶压缩永久变形增大。     

无机填料对三元乙丙橡胶耐汽车合成制动液性能的影响

研究无机填料煅烧陶土、滑石粉、纳米碳酸钙、Creat E_2和强威粉TNK对三元乙丙橡胶耐汽车合成制动液性能的影响。结果表明:对于过氧化物硫化体系,无机填料的种类对体系硫化特性无明显的影响;添加Creat E_2的胶料门尼粘度最小,而添加强威粉TNK的胶料门尼粘度最大;Creat E_2的补强效果最佳;加入纳米碳酸钙和强威粉TNK可以有效降低硫化胶的压缩永久变形;添加Creat E_2的硫化胶耐制动液综合性能最优。     

三元乙丙橡胶压缩永外变形的研究

研究了不同硫化体系，防老剂及试验温度对４种牌号的三元乙丙橡胶的压缩永久变形的影响。结果表明：采用过氧化物ＤＣＰ硫化体系硫化的三元乙丙橡胶ＥＳＰＲＥＮＥ５５３牌号硫化胶，可获得较低的压缩永久变形，且随试验温度的升高呈现近似线性增大的程度也较小；加入３份防老剂ＭＢ，可进一步降低其压缩永久变形。防老剂ＲＤ，防老剂２２４６及３０号机油均可使三元乙丙橡胶压缩永久变形增大。     

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。     

丁腈橡胶与金属扯离强度的影响因素

介绍了硫化体系、胶粘剂及无机填料等因素对丁腈橡胶（ＮＢＲ）与金属扯离强度的影响。硫化剂ＤＴ－ＤＭ对ＮＢＲ与金属扯离强度会产生不利影响，并随其用量增加，这种影响加剧。试验得出：ＮＢＲ胶料硫化体系选用硫黄０．５、促进剂ＴＭＴＤ１．５、硫化剂ＤＴＤＭ１．０、促进剂ＣＺ１．０，无机填料选用轻质氧化镁１５，而胶粘剂选用胶粘剂ＲＭ－１（预固化条件１４０℃×１５～２０ｍｉｎ），胶料与金属的扯度强度和附胶情况良好     

丁腈橡胶/黑液-蒙脱土复合材料压缩永久变形的研究

以造纸黑液和蒙脱土为原料制备黑液-蒙脱土复合物(BL-MMT),并将其作为填料,通过机械混炼制备了丁腈橡胶/黑液-蒙脱土(NBR/BL-MMT)复合材料。考察了BL-MMT用量、硫化体系、填充体系对NBR/BL-MMT复合材料压缩永久变形的影响。实验结果表明:当BL-MMT的用量为50 phr时,使用过氧化物硫化体系的硫化胶压缩永久变形优于硫磺硫化体系,且随着过氧化物含量的增加,硫化胶的压缩永久变形减小。当过氧化物为1.5 phr时,综合性能较好。无机填料填充NBR/BL-MMT(100/50)复合物,将导致硫化胶的压缩永久变形增大。在添加相同量的无机填料时,填充白炭黑的硫化胶压缩永久变形最大,其次为轻质碳酸钙、重质碳酸钙。     

活化剂Struktol A-73在胶料中的应用特性

研究了活化剂Ｓｔｒｕｋｔｏｌ Ａ－７３在天然橡胶及天然橡胶与丁苯橡胶并用胶中的应用特性，结果表明：胶料中加入Ｓｔｒｕｋｔｏｌ Ａ－７３可改善胶料的抗硫化返原性和热稳定性；提高胶料的硫化效率；改进胶料的动态性能；降低胶料的生热和压缩永久变形；与噻唑类硫化促进体系并用，无亚硝胺污染环境的危险；对钢丝粘合性能造成的影响，在胶料老化之后即可降至最小；混炼工艺性能良好。它是一种特别有效的硫化活化剂，一般用量     

硫化体系对CO/ECO共混胶压缩永久变形的影响

研究了不同硫化体系对CO/ECO共混胶的硫化特性，高温压缩交变形的影响。结果表明，采用三嗪类衍生物硫化体系的CO/ECO共混胶高温压缩永久变形较小，增加硫化剂Na-22或TCY的用量或者对胶料进行二次硫化均能减小胶料高温压缩永久变形。在适当的二次硫化条件下。加入适量的TMTD能减小Na-22硫化的共混胶高温压缩永久变形，TMTD用量过多则增大共混胶高温压缩永久变形，在TCY硫化体系中加入TMTD则使得共混胶高温压缩永久变形增加。     

硫化体系对NBR压缩永久变形的影响

试验研究硫化体系类型、硫化剂DCP用量、硫黄用量及促进剂对NBR硫化胶压缩永久变形的影响。结果表明，采用过氧化物硫化体系的硫化胶压缩永久变形最小，普通硫黄硫化体系和镉镁硫化体系的硫化胶最大，半有效和有效硫化体系的硫化胶较小；在过氧化物硫化体系中，当硫化剂DCP用量为2．5份、硫黄用量为0．3份、促进剂TMTD或DPG用量为1．5份时，NBR硫化胶的压缩永久变形较小。     

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。