液压支架密封圈用聚氨酯弹性体的性能

采用不同游离甲苯二异氰酸酯(TDI)含量的预聚体和不同结构的二胺扩链剂3,3'-二氯-4,4'-二氨基二苯基甲烷(MOCA)、3,5-二甲硫基甲苯二胺(E-300)和4,4'-亚甲基双(3-氯-2,6-二乙基苯胺)(MCDEA)制备了一系列用于液压支架密封的聚氨酯(PU)弹性体,考察了游离TDI含量及不同扩链剂对PU弹性体物理机械性能、热性能和动态力学性能的影响。结果表明,采用相同预聚体时,对于不同的扩链剂,当扩链系数为95%时,PU弹性体的综合性能最佳;以MCDEA为扩链剂制得PU弹性体的邵尔A硬度、弹性和定伸应力最高,扯断伸长率最低,低温动态性能最好,而撕裂强度和玻璃化转变温度则以E-300为扩链剂制得的PU弹性体最低,拉伸强度相差较小;以MCDEA和MOCA为扩链剂制得PU弹性体的耐热性优于以E-300为扩链剂制得的PU弹性体;以MOCA为扩链剂制得PU弹性体的高温动态性能最好;采用相同扩链剂时,随着预聚体中游离TDI含量的降低,PU弹性体的弹性、定伸应力、撕裂强度和动态性能提高,扯断伸长率降低和永久变形减小,拉伸强度相差较小。     

质量，企业生命的永恒动力！

三晃是台湾知名的TPU生产商，在产品的质量与技术方面都拥有很好声誉。自1974年创立以来，三晃从事各种人造合成皮革原材料的生产，供给PVC和PU人造皮革。现在，产品的业务逐步拓展到各种油墨、表面处理剂、涂料及PU树脂等领域。对于PU树脂，公司已有10多年的经营研发经验，先后引进日     

发展中的中国石油化学工业——四十二、己内酰胺

己内酰胺,简称e-己内酰胺,白色晶体或结晶性粉末,熔点68～70℃,沸点140～142℃(15毫米)。手触有润滑感,工业品有微弱的叔胺气味,易溶于水、乙醇、乙醚、氯仿和苯等。其70％水溶液的密度是1.05g/cm~3,受热时起聚合反应,用于制备聚己内酰胺树脂、聚己内酰胺纤维和人造皮革等。 1 工艺技术 己内酰胺的工业生产方法,可以归纳为4种: (1)环己烷氧化制环己酮,再与羟胺肟化生成环己酮肟,经Beckmann重排得己内酰胺。 (2)苯酚加氢制环己酮,经肟化、Beckmann重排得己内酰胺。 (3)甲苯氧化制苯甲酸,加氢得环己烷羧酸,与亚硝     

皮革用聚氨酯乳液系列产品通过鉴定

化工部晨光化工研究院一分院和成都市皮革研究所共同研制的皮革用聚氨酯乳液系列产品已于1987年11月通过省级鉴定。专家和用户一致认为:该系列产品的综合技术指标属国内先进,使用性能优于国内同类产品,是生产高档皮革及制品的理想化材料。该系列产品系聚醚型,自乳化,阴离子聚氨酯乳液。是用不同分子量聚醚二醇合成预聚体,用含羧基的半酯化合物引入羧基,多元醇部分扩链或不扩链,最后经乳化制得。共有四个牌号,即补伤剂PU—230、PU—723、固含量为30±2％;涂饰剂PU—     

易染色超细纤维合成革用聚氨酯树脂的研制

以二苯基甲烷二异氰酸酯(MDI)、聚四氢呋喃二醇(PTMG)和聚酯多元醇等为主要原料,合成了一种易染色的聚氨酯(PU)树脂。讨论了树脂100%模量、粘度对超细纤维合成革加工性能的影响以及N-甲基二乙醇胺(MDEA)、二苯基甲烷二胺(MDA)2种扩链剂对聚氨酯树脂物性、染色性能的影响。结果表明:PU树脂100%模量在10MPa左右,粘度在40～60Pa.s时,制得的PU树脂合成革具有良好的物性和染色性能。PU树脂中加入MDA质量分数为2.5%是合成PU树脂的最佳用量;加入MDEA的质量分数为2.0%时的K/S值是不加入MDEA时的10.3倍,单独使用MDEA的用量不宜超过2.0%;MDEA和MDA都能提高染色性,但MDA含量增加,树脂拉伸强度增加,伸长率下降,而加入MDEA的结果刚好相反,因此采用MDA和MDEA混合,nMDA/nMDEA在1∶1～2∶1时,所制得PU树脂物性和染色性均保持较高的水平。     

聚氨酯信息

<正> PU 新发展欧洲技术与以色列研究者联合开发出一类无异氰酸酯 PU,它可用于涂料代替环氧树脂改性 PU。无异氰酸酯 PU 是由环碳酸酯齐聚物与脂肪伯胺反应制得。之所以选择这两原料是由产品最终应用特性所决定的。该产品具有较高的机械性能和抗化学品性能。且比通用 PU 硬,这是因为其结构密实;在     

高固含量丙烯酸酯改性聚氨酯胶粘剂的研制

以聚醚多元醇、聚酯多元醇和蓖麻油为混合多元醇,以改性MDI(4,4′-二苯基甲烷二异氰酸酯)及PAPI(多亚甲基多苯基多异氰酸酯)为混合异氰酸酯,合成了聚氨酯(PU)胶粘剂预聚体;然后以PA(羟基丙烯酸酯树脂)作为PU预聚体的改性剂,制得高固含量的PUA(聚丙烯酸酯改性聚氨酯)胶粘剂。结果表明:当m(改性MDI)∶m(PAPI)=1∶1、n(-NCO)∶n(-OH)=2.2∶1、w(PA)=8%(相对于PU质量而言)和w(丙烯酸羟乙酯)=3%(相对于PU质量而言)时,PUA胶粘剂的综合性能较好。     

PVC/PU共混超滤膜性能研究

PVC膜对糖类化合物有较强的排斥力,但其亲水性差,而聚氨酯有较强的亲水性,本课题研究聚氯乙烯(PVC)与聚氨酯(PU)的共混膜,探讨相转化法制备PVC/PU共混超滤膜的性能。实验结果表明,当聚合物浓度为16%,PVC/PU以8/2(质量分数)共混时,可制的水通量、截留率较好的多孔膜。     

聚氨酯改性的微孔膜的制备与性质

PVC膜对糖类化合物有较强的排斥力,但其亲水性差,而聚氨酯有较强的亲水性,本课题研究聚氯乙烯(PVC)与聚氨酯(PU)的共混膜,探讨相转化法制备PVC/PU共混超滤膜的性能。实验结果表明,当聚合物浓度为16%,PVC/PU以8/2(质量分数)共混时,可制的水通量、截留率较好的多孔膜。     

丙烯酸酯改性水性聚氨酯乳液的制备及性能研究

采用物理共混和核-壳聚合法制备了丙烯酸酯改性水性聚氨酯(PU/PA,PUA)乳液,并对不同改性方法制得的乳液进行了研究。通过红外(FTIR)、透射电镜(TEM)、差示扫描量热(DSC)、热重分析(TGA)、耐水性和力学性能测试等研究了丙烯酸酯改性聚氨酯乳液及涂膜的结构与性能。结果表明具有核-壳结构的PUA乳液涂膜耐水性、耐热性和固含量较水性聚氨酯(PU)有明显的提高,力学性能稍有下降;PUA综合性能优于PU/PA。     

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。