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以异佛尔酮二异氰酸酯(IPDI)、聚醚二元醇(N210)、聚酯二元醇(PBA)为主要原料,二羟甲基丙酸(DMPA)为亲水性扩链剂,一缩二乙二醇(DEG)为小分子扩链剂,乙二胺(EDA)、异佛尔酮二胺(IPDA)为后扩链剂,合成了一系列水性聚氨酯(WPU)乳液。主要考察了后扩链对水性聚氨酯乳液的稳定性,乳液粒径以及胶膜吸水率和力学性能的影响。结果表明,用二胺后扩链之后,乳液稳定性变好,乳液粒径变小,胶膜吸水率减小,耐水性变好,胶膜拉伸强度增加,当采用IPDA后扩链且质量含量为2.7%时,膜的综合性能较好,吸水率相对较低(16.7%),拉伸强度为31.23MPa,断裂伸长率为1022.31%。 相似文献
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采用异佛尔酮二异氰酸酯(IPDI)和聚醚二元醇(N-220)为主要原料,二羟甲基丙酸(DMPA)为亲水扩链剂,乙二胺(EDA)为后扩链剂,合成了一系列聚醚型聚氨酯(WPU)水分散体。考察了nNCO/nOH和中和度的变化对聚氨酯相对分子质量的影响以及聚氨酯相对分子质量与聚氨酯胶膜的力学性能和耐水性的关系。结果表明,随着nNCO/nOH的降低,聚氨酯的相对分子质量呈现先上升后下降的规律;随着中和度的增加,聚氨酯的相对分子质量增加;当nNCO/nOH为1.25时,水性聚氨酯相对分子质量最高,胶膜的力学性能和耐水性最好。 相似文献
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采用分子量为1000的聚丙二醇与甲苯二异氰酸酯反应制得一定异氰酸酯基含量的预聚体,然后加入亲水扩链剂进行扩链,最后加水乳化中和后得到单组分聚氨酯乳液胶粘剂.研究了异氰酸酯指数(R值)、亲水扩链剂和中和剂对聚氨酯乳液胶粘剂性能的影响.当R=3.5,亲水扩链剂用量为7%,中和度为100%时,单组分聚氨酯乳液胶粘剂综合性能较... 相似文献
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乙二胺扩链剂对水性聚氨酯性能的影响 总被引:5,自引:1,他引:5
以聚醚220、异佛尔酮二异氰酸酯(IPDI)为主要原料,二羟甲基丙酸(DMPA)为亲水性扩链剂,丁二醇(BD)和乙二胺(EA)为小分子扩链剂,按不同配比合成了系列水性聚氨酯分散体。主要考察了乙二胺扩链剂用量对水性聚氨酯乳液的稳定性、乳液粒径、粘度以及膜吸水性和力学性能的影响。结果表明,随乙二胺扩链剂用量的增加,乳液粒径增大、分散稳定性变差、粘度减小、胶膜的拉伸强度增加、断裂伸长率减小、耐溶剂性增加、吸水率变化不明显、硬段相Tg升高,软硬段相分离程度增加。胶膜的ATR红外表现为PPG类聚醚型聚氨酯典型的红外光谱。 相似文献
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热红外隐身涂料用水性聚氨酯的制备研究 总被引:1,自引:0,他引:1
以聚碳酸酯二元醇(PCDL)为软段,异佛尔酮二异氰酸酯(IPDI)为硬段,二羟甲基丙酸(DMPA)为亲水扩链剂,三乙胺为成盐剂,乙二胺为二次扩链剂,采用自乳化法合成了聚碳酸酯基低红外发射率水性聚氨酯。采用红外光谱仪(FI-IR)、红外发射率测试仪等对聚氨酯的结构和红外性能进行了表征。研究了PCDL/IPDI比例、亲水扩链剂、中和剂和二次扩链剂对合成水性聚氨酯胶膜红外发射率的影响。结果表明:PCDL/IPDI质量比为2.5∶1,DMPA的量为单体总量的6%,中和度为100%,控制二次扩链剂乙二胺的加入量使得—NH3与—NCO的物质的量比为1.5∶1时,所合成的乳液粘合剂在8~14μm波段红外基本透明,红外发射率可低至0.825,涂膜物理综合性能良好,可以应用于隐身涂层。 相似文献
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疏水型阳离子水性聚氨酯的合成与性能研究 总被引:1,自引:0,他引:1
以甲苯二异氰酸酯,聚酯、聚醚混合多元醇为基本原料,N-甲基二乙醇胺(MDEA)为亲水扩链剂,羟丙基聚二甲基硅氧烷、单硬酯酸甘油酯为改性剂,通过醋酸中和反应制备出疏水型自乳化阳离子水性聚氨酯乳液;研究了改性剂用量、R值(体系中—NCO和—OH的物质的量比)、MDEA含量和中和度对乳液耐水性的影响。结果表明:羟丙基聚二甲基硅氧烷和单硬酯酸甘油酯加入到聚氨酯体系中,均能显著提高聚氨酯的耐水性;胶膜吸水率随MDEA含量增加呈先降低后升高的趋势;当中和度小于100%时,胶膜吸水率随中和度的增大而减小;当中和度大于100%时,中和度对胶膜吸水率无明显影响。 相似文献
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M. S. J. Simmonds W. M. Blaney F. Delle Monache M. Marquina Mac-Quhae G. B. Marini Bettolo 《Journal of chemical ecology》1985,11(12):1593-1599
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. 相似文献
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Cheng-Le Zhao Shane Porzio Alan Smith Haiyan Ge H. T. Davis L. E. Scriven 《Journal of Coatings Technology and Research》2006,3(2):109-115
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. 相似文献
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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. 相似文献
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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. 相似文献
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中蓝晨光化工研究院《塑料工业》编辑部 《塑料工业》2007,35(3):1-25,67
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。 相似文献
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中蓝晨光化工研究院有限公司《塑料工业》编辑部 《塑料工业》2009,37(3)
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. 相似文献