SBR/TPI并用胶硫化体系的研究

研究硫化体系类型、硫黄用量和促进剂NOBS用量对SBR/反式 1,4 聚异戊二烯 (TPI)并用胶性能的影响。结果表明 ,采用普通硫黄硫化体系 ,硫黄用量为 2 .5份、促进剂NOBS用量为 1.2份时SBR/TPI并用胶可以获得良好的综合性能 ;硫黄用量较小时 ,胶料的热老化性能较好 ;适当增大促进剂NOBS用量 ,可改善胶料的动态生热性能。     

NR/BR/TPI共混物硫化体系的研究

研究了普通硫化体系(CV)、半有效硫化体系(SEV)和有效硫化体系(EV)对NR／BR，TPI共混物(共混比为40／40／20)性能的影响，特别是CV体系中硫黄和促进剂DM用量的影响。结果表明，采用CV体系，NR／BR／TPI共混物的耐疲劳性能等物理性能较好，硫黄用量为3份、促进剂DM用量为1份时，共混物的撕裂强度和耐屈挠性能最好，其它性能也保持在较高水平。配合剂直接加入共混胶中混炼比分别加入3种生胶混炼后再加以混合的方式可获得更好的力学性能，但正硫化时间和焦烧时间缩短。     

NR/TPI并用胶半有效硫化体系的研究

考察了促进剂NS用量、硫黄用量和硫载体DTDM对NR/反式-1,4-聚异戊二烯(TPI)并用胶性能的影响.结果表明,在半有效硫化体系中,硫黄用量1.2～1.4份,促进剂NS用量1.4～1.6份时,NR/TPI(80/20)并用胶可以获得良好的综合性能.NR/TPI中使用DTDM后,硫化速度虽略有降低,但胶料焦烧时间延长,加工安全性提高,硫化胶物理机械性能、疲劳性能、滚动阻力以及耐老化性能均得到改善,这与DTDM在NR中的应用相似.     

优化配方设计提高9.00－20 16PR轮胎的综合性能

通过对9.00-20 16PR轮胎胎冠胶、缓冲层、胎肩胶和胎体帘布层内外层胶的配方优化,提高了轮胎的速度、耐久性能.胎冠胶采用NR/BR(50/50)并用、炭黑N234/N220并用(用量54份);胎肩胶采用NR/BR(90/10)并用、硫化体系为促进剂NOBS、硫化剂DTDM和硫黄;缓冲胶采用全NR,炭黑N330/N660并用(用量44份)、硫化体系为促进剂CZ、不溶性硫黄与硫化剂DTDM;内外层胶采用NR/SBR/BR并用、炭黑N330/N660并用(用量40份)、硫化体系采用促进剂NOBS、DM、硫化剂DTDM和硫黄并用.改进后轮胎的速度性能达到110 km·h-1级运转h,耐久性超过120h.     

EPDM硫黄硫化体系的优化设计

研究由硫黄、促进剂M、TRA和BZ组成的硫黄硫化体系对EPDM胶料性能的影响，特别是在总有效硫用量为1．5份、促进剂M用量为0．5份情况下，硫黄、促进剂TRA和BZ用量变化对EPDM胶料硫化特性和焦烧性能、硫化胶物理性能和耐老化性能的影响，并用等高线法进行分析。结果表明，促进剂BZ和TRA的用量不宜高于0．8份，硫黄／促进剂TRA／BZ适宜配比应保持在普通硫化体系的范围。     

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。     

硫化体系对NBR胶料性能的影响

试验研究7种硫化体系对NBR胶料性能的影响.结果表明,在普通硫化体系、半有效硫化体系、有效硫化体系、过氧化物硫化体系、硫黄/过氧化物并用硫化体系、无硫硫化体系和平衡硫化体系中,半有效硫化体系胶料具有合适的焦烧时间、较短的正硫化时间、较高的拉伸强度和撕裂强度以及优良的耐老化性能.在半有效硫化体系中,硫黄/促进剂NOBS用量比为1/1、硫黄用量为1.4～1.8份时,NBR胶料具有较好的综合性能,符合油封制品的实际要求.     

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。     

均匀设计在电梯导靴轮胶料硫化体系优化中的应用

通过均匀设计试验研究硫化体系中硫黄和促进剂M用量对电梯(直梯)导靴轮胶料及成品性能的影响,并确定优化的硫黄和促进剂M用量。结果表明:与硫黄用量相比,促进剂M用量对胶料性能的影响更显著;促进剂M用量对混炼胶的t10和Fmax,硫化胶的硬度、拉伸强度、拉断伸长率和拉断永久变形,成品导靴轮的硬度和低频噪声影响显著;硫黄用量对硫化胶的硬度、拉伸强度和拉断伸长率,成品导靴轮的硬度影响显著;促进剂M用量取1～1. 5份、硫黄用量取2～3份为宜。     

复合硫化体系对ACM/NBR共混胶性能的影响

分别采用TCY/硫黄、3#硫化剂/硫黄/促进剂、皂/硫黄/促进剂3种复合硫化体系硫化ACM/NBR共混胶。研究不同复合硫化体系、TCY用量和硫黄用量对ACM/NBR共混胶硫化特性、力学性能、耐热老化性能、耐油性能和压缩永久变形性能的影响,结果表明,TCY/硫黄复合硫化体系硫化的ACM/NBR共混胶的综合性能优于3#硫化剂/硫黄/促进剂和皂/硫黄/促进剂复合硫化体系,当TCY/硫黄的用量为1.5/0.3份时,ACM/NBR共混胶具有良好的综合物理机械性能。     

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。