聚氯醇醚聚氨酯胶粘剂的研究

本文以环氧氯丙烷聚醚、环氧丙烷聚醚及其混合物、环氧丙烷—环氧氯丙烷共聚醚与甲苯二异氰酸酯反应制得预聚体;以三羟甲基丙烷和二乙醇胺为交联剂,制得一系列聚醚型聚氨酯胶粘剂,并对不同配方,不同固化条件及单组分和双组分的胶对粘接强度的影响作了初步的研究。结果表明:1、胶粘剂的粘接强度与硬段含量、聚环氧氯丙烷聚醚的含量成正比;2、室温下,共聚醚聚氨酯胶粘剂的粘接强度比共混聚醚聚氨酯胶粘剂的粘接强度大;3、用分子量分布宽的聚醚制成的胶粘剂,有较好的粘接强度。     

聚氨酯反应性热熔胶粘剂进展

近年来聚氨酯反应性热熔胶粘剂上市的商品很多,目前聚氨酯反应性热熔胶粘剂一般以聚酯型端NCO聚氨酯预聚物为主成分,配以适当的增粘树脂、软化剂、稳定剂、催化剂、填料等成分。近来报道的聚氨酯反应性热熔胶粘剂配方除主要为聚酯型MDI预聚体为主成分外,还有以聚醚-聚酯混合型预聚体为主成分,甚至研究全由聚醚型预聚体为主成分的聚氨酯反应性热熔胶粘剂。聚醚型聚     

改性聚氨酯胶粘剂的研究

本文采用一种新的聚酯聚醚树脂作聚氨酯的柔性链段,带有支化点的有苯环结构的多异氰酸酯化合物为刚性链段,引进了较多的苯环结构和支化点以增加聚氨酯胶粘剂的内聚强度和固化时的交联密度,使改性后的胶粘剂具有优良的耐高、低温性能,良好的粘接强度。文中介绍了制备方法,着重讨论了聚酯聚醚预聚体,羟基聚氨酯,固化条件及固化剂用量对胶粘剂性能的影响。     

聚氨酯弹性体的合成及其阻尼性能的研究

以端羟基聚环氧氯丙烷为原料,采用半预聚体制备聚氨酯弹性体;对端羟基聚环氧氯丙烷和聚氨酯弹性体的阻尼性能进行了表征,并研究了半预聚体中—NCO的的质量分数、弹性体中硬段的质量分数、异氰酸酯的种类和聚醚的相对分子质量对聚氨酯弹性体阻尼性能的影响。结果表明:聚氨酯弹性体具有良好的阻尼性能,降低半预聚体中—NCO的质量分数、弹性体中硬段的质量分数、端羟基聚环氧氯丙烷的相对分子质量和使用异氰酸酯TDI-80可以提高聚氨酯弹性体的阻尼性能。     

聚氨酯弹性体软段对其力学性能的影响

先用4,4'-二苯基甲烷二异氰酸酯(MDI)与不同相对分子质量不同种类低聚物多元醇合成预聚体,再以1,4-丁二醇(BDO)为扩链剂制备聚氨酯弹性体,考察了软段对聚氨酯弹性体力学性能的影响.结果 表明:当预聚体NCO含量相同时,聚酯型聚氨酯弹性体的力学性能整体优于聚醚型的,随低聚物多元醇相对分子质量的增加,聚氨酯弹性体的...     

四氢呋喃均聚醚聚氨酯弹性体——影响PTMG-PU力学性能的因素

介绍四氢呋喃均聚醚（PTMG）聚氨酯弹性体的力学性能。讨论了化学结构因素对聚氨酯弹性体力学性能的影响,化学结构因素包括PTMG相对分子质量、二异氰酸酯、扩链剂、硬段质量分数、预聚体NCO基质量分数和化学交联等。结果表明：影响聚氨酯弹性体硬度和拉伸强度最大因素是二异氰酸酯类型和预聚体NCO基质量分数,影响聚氨酯弹性体扯断伸长率最大因素是PTMG相对分子质量和交联密度。     

预聚体法制备聚醚聚氨酯胶粘剂

以四氢呋喃-环氧丙烷共聚醚三醇、甲苯二异氰酸酯、1，4-丁二醇、白炭黑为原料，合成了聚醚预聚体，以四氢呋喃-环氧丙烷共聚醚三醇为固化剂，制备了双组分无溶剂聚氨酯胶粘剂。研究了硬段比例，NCO质量分数、白炭黑用量、预聚体贮存时间等因素对预聚体和胶粘剂性能的影响，测试了预聚体的粘度和NCO质量分数，以及胶粘剂固化物的力学性能，粘接强度。测试结果表明，将1，4-丁二醇（BG）和四氢呋喃-环氧丙烷共聚醚三醇（JF）的羟基摩尔比值控制在1.5，NCO质量分数控制在5.6%左右，白炭黑用量为10g，可以获得工艺性能和贮存性能良好的聚醚预聚体，与聚醚固化剂配制，可以获得比较高而且稳定的力学性能和粘接强度。     

鞋用水性聚氨酯胶粘剂的研究进展

介绍了水性聚氨酯胶粘剂的特点、分类、制备及其在制鞋领域的应用情况，并对其在该领域的前景进行了展望。即使不使用交联剂，水性聚氨酯胶粘剂仍具有耐温性好、固化温度低的特点。根据产物链段上亲水基团的性质，水性聚氨酯分为离子型和非离子型两大类，而离子型又分为阳离子型和阴离子型。水性聚氨酯的制备方法是将低聚物二醇和二异氰酸酯反应制成端NCO基聚氨酯预聚体，然后使预聚体在水中进行乳化，通过扩链反应，使预聚体链增长，形成高相对分子质量的聚氨酯。一种新型单组分水性聚氨酯胶粘剂研制成功，它将取代现在制鞋行业采用的双组分水性聚氨酯胶粘剂。它的主要优点是：适用于多种材料的粘接，对工作环境不造成污染。     

聚醚-聚酯型水性聚氨酯胶粘剂的合成

文章以聚醚二元醇、聚酯二元醇为软段,以甲苯二异氰酸酯、1,4-丁二醇等为硬段,采用两步法合成水性聚氨酯胶粘剂。研究了亲水基团的含量、异氰酸酯基(-NCO)与羟基(-OH)的摩尔比、聚醚/聚酯二元醇复配比例等对水性聚氨酯胶粘剂性能的影响。结果表明:亲水性基团含量1.5%～1.7%,异氰酸酯基与羟基的摩尔比为1.13～1.27,聚醚/聚酯复配比例为25/75～35/65时所合成的胶粘剂对BOPP/PET软包装复合材料有较佳的粘结性能。     

软链段结构对聚氨酯弹性体胶粘剂性能的影响

合成了以聚己二酸-乙二醇聚酯二醇、聚己二酸-丁二醇聚酯二醇、聚己二酸-己二醇聚酯二醇为软链段的含羟基的聚氨酯胶粘剂样品。利用DSC和TEM等现代测试手段对聚氨酯胶粘剂的结晶行为和形态结构进行了表征。并探讨了软链段结构对聚氨酯胶粘剂粘接性的影响。     

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.     

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。     

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.