碳纤维对橡胶复合材料性能的影响

用高性能的碳纤维(CF)作增强剂,橡胶作基相及偶联剂作为相容剂制备了CF/橡胶复合材料。用CF增强顺丁橡胶(BR)、丁苯橡胶(SBR)、天然橡胶(NR)、丁腈橡胶(NBR)、三元乙丙橡胶(EPDM)4640、4045及4045M、氯丁橡胶(CR)、丙烯酸酯橡胶(ACM)和甲基乙烯基硅橡胶(MVQ),通过力学性能和热老化测试,确定CF适合增强的胶种及用量。用偶联剂作相容剂研究了偶联剂对橡胶和CF相容性的影响;通过红外光谱(IR)和扫描电镜(SEM)分析了CF和橡胶交联结构的相容性。结果表明,CR为基相,复合材料的力学性能最好;MVQ作基相,复合材料的热稳定性最好。获得最佳力学性能配方为:CR 100份,CF 12份,偶联剂KH550 2.5份,白炭黑20份,防老剂D 1份,促进剂M 1份,硬脂酸1份,硫黄1份,氧化锌8份。CF增强CR的最佳固化条件为:固化温度175℃,固化压力10MPa,固化时间30min。通过SEM和IR分析,进一步确定CF、KH550和CR的混合相容性最好。     

短切碳纤维/氟橡胶复合材料性能研究

利用碳纤维增强氟橡胶,研究了碳纤维含量对氟橡胶力学性能的影响,偶联剂对碳纤维/氟橡胶复合材料性能的影响,确定碳纤维增强氟橡胶的最佳用量及制备复合材料的最佳硫化条件,通过红外光谱(IR)和扫描电镜(SEM)分析探讨碳纤维/氟橡胶橡胶复合材料的形貌和结构。结果表明,短切碳纤维与氟橡胶的最佳质量比为12∶100,偶联剂为3-氨丙基三乙氧基硅烷(KH500),其用量为2.5份。最佳硫化条件为:硫化时间为15min,硫化温度为170℃,硫化压力为10MPa。红外光谱表明,碳纤维与氟橡胶之间生成了C—Si—O化学键,提高了氟橡胶和碳纤维的相容性,扫描电镜(SEM)表明用偶联剂KH550处理过的碳纤维在橡胶中的排列整齐,无明显断面、孔隙,相界面之间结合得很好。     

改性粉煤灰填充废胶粉复合材料研究

以废胶粉（URP）为基体相,粉煤灰（FA）为增强相,烷偶联剂为相容性制备了粉煤灰/废胶粉复合材料。研究了废胶粉和粉煤灰的最佳用量和偶联剂的用量,混合方式和最佳的硫化条件。通过扫描电镜（SEM）和红外光谱（FT-IR）分析了粉煤灰/废胶粉试样的结构和形貌。结果表明：用Si-69对粉煤灰的改性效果好于KH-550。废胶粉最佳用量为100份,粉煤灰40份,Si-69 1.0份。最佳的初混方式为热混,偶联剂先与粉煤灰混合,而后再与废胶粉混合。最佳硫化条件为：温度160℃,压力8MPa,时间25 min。Si-69/FA/URP比KH-550/FA/URP的相容性要好。硅烷偶联剂中的Si—OH和粉煤灰表面的—OH发生脱水缩合,形成了Si—O键;偶联剂的有机端和废胶粉形成了C—H键,从而改善了FA/URP复合材料相容性和力学性能。     

碳纤维增强氯丁橡胶复合材料的制备及性能

用碳纤维（CF）作增强相、氯丁橡胶（CR）作基相及硅烷偶联剂作相容剂,制备了CF/CR复合材料,考察了CF用量、硅烷偶联剂的种类及用量、硫化条件对复合材料热老化前后性能的影响,并用扫描电子显微镜（SEM）和傅里叶变换红外光谱（FTIR）仪对其结构进行了表征。结果表明,制备CF/CR复合材料的最佳配方为:CR 100份,CF 12份,KH 550 2.5份;最佳硫化条件为:温度175℃,压力10 MPa,时间30 min。SEM和FTIR分析表明,KH 550处理的CF比未处理及用Si 69处理的CF与CR的相容性更好。     

玄武岩短纤维增强硅橡胶复合材料的制备及性能

采用玄武岩短纤维(BF)增强硅橡胶,制备了BF/硅橡胶复合材料,考察了硅烷偶联剂的种类、BF用量以及硫化条件对复合材料力学性能的影响,并用扫描电子显微镜观察了复合材料的微观形貌。结果表明,用KH 550对BF进行表面处理,所得复合材料的力学性能优于以Si 69处理的材料;当BF用量为20份时,BF/硅橡胶复合材料的力学性能最好;制备复合材料的最佳硫化条件为10 MPa×175℃×25 min;用KH 550处理BF,BF与硅橡胶的相容性比用Si 69处理的好。     

短切碳纤维增强氟橡胶复合材料的制备及表征

采用短切碳纤维(CF)增强氟橡胶(FR),制备了短切CF/FR复合材料,考察了短切CF的用量、偶联剂的种类以及硫化条件对复合材料力学性能的影响,并采用傅里叶变换红外光谱和扫描电子显微镜对复合材料的微观结构和形貌进行了表征。结果表明,短切CF的用量为12份时,制备的短切CF/FR复合材料的综合性能最佳; 用硅烷偶联剂KH 550对短切CF进行表面处理,制备的短切CF/FR复合材料的力学性能优于以Si 69处理的材料; 制备短切CF/FR复合材料的最佳硫化条件为10 MPa×170℃×15 min; 短切CF与FR之间存在化学键的结合,提高了短切CF与FR的相容性; 用偶联剂KH 550处理短切CF,短切CF与FR的相容性最好。     

竹粉的表面改性及其对聚丙烯基复合材料性能的影响

用偶联剂KH-550和硬脂酸对氢氧化钠溶液(10wt%)处理过的竹粉(BF)表面进行二次改性,然后通过熔融挤出制备了竹粉/聚丙烯(BF/PP)木塑复合材料.采用热重-差热分析(TG/DTA)、红外光谱(FTIR)、X射线衍射(XRD)和原子力显微镜(AFM)等对改性前后竹粉的微观结构进行表征.结果表明,改性后BF的热稳定性升高,比表面积增大,形成疏松的纤维聚集束;复合材料的力学性能显著提高;其中用KH-550改性竹粉制备的复合材料力学性能最佳,冲击强度较纯PP提高了83%.复合材料冲击断面扫描电镜(SEM)显示,KH-550改性可以明显提高BF与PP基体树脂间的相容性.     

碳纤维/硅橡胶复合材料的制备

以硅烷偶联剂为相容剂研制碳纤维/硅橡胶复合材料。最佳配方为硅橡胶100,白炭黑20,碳纤维12,偶联剂KH-550 2.5,三氧化二铁1,硬脂酸1,防老剂D 1,交联剂DCP 5,促进剂M 1;最佳一段硫化条件为175℃/10 MPa×30 min,最佳二段硫化条件为200℃(常压)×2 h。     

玄武岩短纤维/硅橡胶复合材料性能研究

采用玄武岩短纤维补强硅橡胶,研究玄武岩短纤维/硅橡胶复合材料的性能。结果表明:用丙酮脱玄武岩短纤维表面的浆膜,处理时间为50 min时效果最佳;用偶联剂KH-550对玄武岩短纤维表面进行处理,且玄武岩短纤维用量为20份时,玄武岩短纤维/硅橡胶复合材料的综合性能最佳;制备玄武岩短纤维/硅橡胶复合材料的最佳硫化条件为175℃/10 MPa×25 min。     

玄武岩短纤维/硅橡胶/氟橡胶复合材料制备及表征

以氟橡胶(FMK)和硅橡胶(MVQ)为基体,用玄武岩短纤维作增强相制备了玄武岩短纤维/MVQ/FMK复合材料,研究了MVQ/FMK的最佳并用比,玄武岩短纤维的长径比、用量及表面处理,二段硫化条件对复合材料力学性能的影响,用扫描电镜(SEM)和红外光谱(IR)分析表征了玄武岩短纤维和FMK/MVQ的相容性。结果表明,MVQ/FMK(质量比)为10/90时,并用胶的力学性能最好,使用长径比为1 800的玄武岩短纤维7份时,玄武岩短纤维/MVQ/FMK复合材料的力学性能最佳,最佳的二段硫化条件是200℃×6h。SEM和IR分析得出γ-巯丙基三甲基硅烷(KH-590)、双(γ-三乙氧基硅基丙基)四硫化物(Si69)在玄武岩短纤维表面发生了明显的化学反应,而且KH590处理的玄武岩短纤维与MVQ/FMK的相容性较好。     

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。