HTBN/蓖麻油基聚氨酯脲材料的制备与性能

以可再生的蓖麻油、端羟基聚丁二烯-丙烯腈(HTBN)、甲苯二异氰酸酯(TDI)为原料,采用预聚体法合成了一系列的聚氨酯脲材料(PUU),对其力学性能进行了测定,并采用DSC和TG对材料进行了热分析。结果表明,随着HTBN用量的增加,材料的拉伸、撕裂强度表现出先增加后降低的趋势,断裂伸长率先降低后增加,硬度表现出一定的下降。HTBN/蓖麻油基软段共混型PUU的耐热性能明显优于纯蓖麻油型PUU。     

HTBN／蓖麻油基聚氨酯脲材料的制备与性能

以可再生的蓖麻油、端羟基聚丁二烯-丙烯腈（HTBN）、甲苯二异氰酸酯（TDI）为原料,采用预聚体法合成了一系列的聚氨酯脲材料（PUU）,对其力学性能进行了测定,并采用DSC和TG对材料进行了热分析。结果表明,随着HTBN用量的增加,材料的拉伸、撕裂强度表现出先增加后降低的趋势,断裂伸长率先降低后增加,硬度表现出一定的下降。HTBN／蓖麻油基软段共混型PUU的耐热性能明显优于纯蓖麻油型PUU。     

聚碳酸酯二醇/蓖麻油基聚氨酯(脲)弹性体的制备及性能

以蓖麻油和聚碳酸酯二醇(PCDL)为共混软段,分别以1,4-丁二醇(BDO)和3,5-二甲硫基-2,4-二胺基甲苯(DMTDA)为扩链剂,用预聚体法合成出一系列聚氨酯(PU)和聚氨酯脲(PUU)弹性体,考察了异氰酸基(NCO)含量和PCDL用量对弹性体力学性能的影响,并对弹性体的热性能进行了分析。结果表明,随着预聚体中NCO含量的增加,PU、PUU弹性体的硬度和强度逐渐上升,当NCO质量分数为8%时,弹性体的拉伸强度最高,而扯断伸长率呈单调下降趋势;随着PCDL用量的增加,弹性体的拉伸强度先升高后下降,扯断伸长率和永久变形逐渐增加;用DMTDA为扩链剂制备的PUU比用BDO制备的PU具有更高的拉伸强度和撕裂强度;PCDL/蓖麻油基PUU的耐热性能优于纯蓖麻油基PUU,PUU的耐热性优于PU。     

邻接交联型聚氨酯弹性体的制备与性能

以聚四氢呋喃醚二醇(PTMG)、端羟基聚丁二烯-丙烯腈(HTBN)和交联剂N,N-间苯撑双马来酰亚胺(HVA-2)作为共混软段,甲苯二异氰酸酯(TDI)为硬段,3,5-二甲硫基甲苯二胺(DMTDA)为扩链剂制备出邻接交联型聚氨酯脲(PUU),研究了硬段含量、交联密度和温度对其力学性能的影响,深入探讨了交联密度对材料热稳定性和低温热性能的影响。采用平衡溶胀法、高低温力学测试、热失重分析法(TGA)、差示扫描量热分析法(DSC)等测试手段对材料的交联密度、力学性能以及热性能进行分析表征。结果表明,当硬段质量分数为39%时,制备的线型PUU力学性能最好;HVA-2的加入增加了PUU的交联密度,提高了材料的热性能和力学性能。当交联密度为0.947×10-3 mol/cm3时,交联型PUU比线型PUU的拉伸强度提高了17.3%,最大分解温度提高了20.1℃,玻璃化转变温度(Tg)增加了5℃。     

内交联水性聚氨酯脲的制备及性能表征

以二羟甲基丙酸(DMPA)、异佛尔酮二异氰酸酯(IPDI)、乙二胺作为硬段,聚醚多元醇(GE220)为软段,以蓖麻油(CA)和三羟甲基丙烷(TMP)多元醇为内交联剂,制备了两个系列的交联型水性聚氨酯脲(PUU)分散液,测定了PUU水分散液及其膜的物理性能和力学性能.结果表明,与未交联的PUU水分散液相比,交联型PUU表现出较好的疏水性能,吸水率从52.4%下降到12.0%,力学性能也有较大程度的提高.随交联剂用量的增加,尽管水分散液的粒径略有增加,但成膜后的耐水性增强,力学性能提高.     

航空透明件抗风沙侵蚀聚氨酯丙烯酸酯涂层研究

以聚醚PTMG-1000、N-330与异佛尔酮二异氰酸酯制得的聚氨酯预聚体和羟基丙烯酸树脂为主要原料,制备了聚氨酯丙烯酸酯(PUA)涂层,并对涂层的表面状态、透光度、雾度、抗风沙侵蚀性能和抗紫外老化等性能进行了研究。结果表明,随着PTMG-1000含量的增加,PUA涂层的透明性增加;当PTMG-1000/N-330的摩尔比为5/1时,涂层具有良好的外观,涂覆有机玻璃的透光度达到92.3%,雾度仅为0.41%,经过风沙实验后透光度为92.2%,雾度为2.49%;光稳定剂和抗氧剂可以显著提高涂层的耐紫外老化性能。该涂层可用于风沙环境中航空透明件的表面防护。     

二缩水甘油乙醇胺封端聚氨酯/环氧树脂胶粘剂的研制

以二缩水甘油乙醇胺(DGEEA)作为端-NCO型PU(聚氨酯)预聚体的封端剂,合成了具有高反应活性的GAPU(端缩水甘油胺型聚氨酯)。采用红外光谱(FT-IR)法对其结构进行表征,应用滴定分析法确定了中间产物和目标产物的羟值、环氧值和-NCO值,考查了不同柔性链段对产品力学性能的影响。结果表明:间苯二甲胺(m-XDA)作为EP/GAPU体系的固化剂,具有相对最好的固化效果;当多元醇为聚四氢呋喃醚二醇(PTMG-1000)时,PTMG-1000-GAPU/m-XDA体系的综合力学性能较好,其剪切强度为8.28 MPa,剥离强度为1.52 kN/m。     

日本开发出反应性热塑聚氨酯弹性体

日本爱知工业大学利用原位反应直接制备出反应热塑性聚氨酯弹性体(TPU),并将之用于环氧树脂改性(制备TPU所用多元醇为PTMG-650、PTMG-1000、PTMG-2000和PTMG-3000,多异氰酸酯为MDI,环氧树脂为Epikote 828)。试验结果表明:用TPU改性的环氧树脂在钢-钢粘接中的粘接强度、弯曲强度和韧性等都有明显提高。用热分析和扫描电镜对固化物的动力学粘弹性进行研究,发现:固化物形态与多元醇相对分子质量、TPU分子结构中的硬段类型有关。     

TPU改性环氧树脂

日本利用原位反应在环氧树脂中直接制备反应性热塑性聚氨酯弹性体(TPU)，所用原料巾多元醇为PTMG-650、PTMG-1000、PTMG-2000和PTMG-3000，多异氰酸酯为MDI，环氧树脂为Epikote828。     

异氰酸酯类型对蓖麻油基聚氨酯性能的影响

以4,4-二环己基甲烷二异氰酸酯(HMDI)、异氟尔酮二异氰酸酯(IPDI)、蓖麻油基多元醇为主要原料,在不添加扩链剂及交联剂的情况下,采用两步法(预聚体法)制备了蓖麻油基聚氨酯材料。通过动态力学性能(DMA)、热失重(TGA)及力学性能测试等手段对聚氨酯材料的性能进行测试,探究异氰酸酯类型及溶剂对蓖麻油基聚氨酯材料性能的影响。结果表明:HMDI型聚氨酯材料的拉伸强度与耐热性能均优于IPDI型聚氨酯材料,但IPDI型聚氨酯材料的断裂伸长率相对较高;采用丙酮作为溶剂会在降低材料拉伸强度与耐热性能的同时提高材料的断裂伸长率;蓖麻油基聚氨酯材料具有较高的损耗因子(tanδ),因此其具有优异的阻尼性能,有效阻尼温域集中于常温区域。     

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。