硅烷封端聚氨酯预聚体的合成研究

以聚醚二元醇、二异氰酸酯为主要原料合成了硅烷封端聚氨酯预聚体,使用合成得到的预聚体制备了硅烷封端聚氨酯密封胶并对其性能进行了考察。研究了二异氰酸酯类型,NCO/OH比例,反应温度,扩链剂类型及封端剂类型对硅烷封端聚氨酯(SPU)的影响。结果表明:使用两种混合二异氰酸酯,NCO∶OH=1.3～1.5,二甘醇作为扩链剂,γ-巯丙基三甲基硅烷(KH590)作为封端剂,反应温度85℃制备得到较理想的预聚体,可使硅烷封端聚氨酯密封胶拉伸强度达到1.78MPa,断裂伸长率达到490%。     

硅烷改性对单组分湿固化聚氨酯胶粘剂性能的影响

采用3-巯丙基三甲氧基硅烷制备了硅烷改性单组分湿固化聚氨酯胶粘剂（SPU）。采用红外光谱、核磁共振氢谱、凝胶渗透色谱和扫描电子显微镜分析了SPU胶粘剂的结构,使用万能电子试验机、邵氏A硬度计测定了硅烷含量对SPU胶粘剂的力学性能、粘接性能与硬度的影响。研究结果表明：3-巯丙基三甲氧基硅烷成功反应到聚氨酯分子链上,减少了体系中异氰酸根（—NCO）的含量;随着硅烷用量的增加,SPU胶粘剂的拉伸强度与拉伸剪切性能升高,硬度降低,表干时间延长;当硅烷用量为理论用量的110%时,SPU胶粘剂的拉伸强度和拉伸剪切强度分别达0.58、0.72 MPa,比纯PU胶粘剂分别提高了7.41%、63.64%;SPU胶粘剂固化时产生的气泡显著减少,外观明显改善。     

硅烷封端羟基硅油改性端硅氧烷聚氨酯密封胶的研究

用2,4-甲苯二异氰酸酯(TDI)、α,ω-二羟基聚二甲基硅氧烷、聚醚多元醇和硅烷偶联剂为原料,分别制备了硅烷封端的羟基硅油(SHS)和端硅氧烷聚氨酯(SPU),并将其共混制备出硅烷封端羟基硅油改性的SPU密封胶。用红外光谱对预聚体进行了表征,考察了密封胶的力学性能。结果表明,添加的硅烷封端羟基硅油与SPU的质量比为50∶100时,SPU密封胶在保持高拉伸强度的同时,断裂伸长率比未添加硅烷封端羟基硅油的密封胶提高了46.7%。通过改变硅烷偶联剂的种类、填料和催化剂的种类和添加量,找到了偶联剂、填料和催化剂对硅烷封端羟基硅油改性SPU密封胶力学性能的影响规律。     

导热硅烷改性聚氨酯粘接剂的制备及性能研究

以聚醚和二异氰酸酯合成聚氨酯，并用硅烷进行封端制得硅烷改性聚氨酯（SPU）预聚体，再添加导热填料、助剂等制备了导热硅烷改性聚氨酯粘接剂。研究了聚醚分子量、异氰酸酯、封端硅烷和导热填料对SPU粘接剂性能的影响。研究结果表明：随着聚醚分子量增加，粘接剂的拉伸强度和硬度不断下降，断裂伸长率不断升高，导热性能基本不变；异氰酸酯结构中的苯环和对称结构有利于提高粘接剂的刚性，降低粘接剂的韧性，对导热性能影响小；三甲氧基硅烷封端制备的粘接剂的拉伸强度和断裂伸长率均高于六甲氧基硅烷封端制备的粘接剂，三甲氧基硅烷相比于六甲氧基硅烷更适合作封端剂；氧化铝粒径越小，越有利于提高导热性能，复合粒径制备的粘接剂导热性能高于单一粒径的导热性能；在60～80份范围内，随着导热填料用量不断增加，导热系数不断增大，导热性能越来越好。     

硅烷改性聚氨酯胶粘剂的研制

介绍了硅烷改性聚氨酯预聚体的物性,以自制硅烷改性聚氨酯预聚体为主要原料制备了单组分端硅烷基的聚氨酯胶粘剂,研究了不同原料配比对其性能的影响。该胶拉伸强度为2.94~3.52 MPa、断裂伸长率为182%~400%。     

增塑剂对硅烷化聚氨酯密封胶性能的影响

以自制的硅烷化聚氨酯预聚物为主要原料,配合补强填料、增量填料、固化催化剂等配制成湿固化硅烷化聚氨酯(SPU)密封胶。通过溶胀实验和动态力学性能分析,讨论了增塑剂对SPU密封胶的溶胀性能、增塑效率以及力学性能的影响。结果表明,氯化石蜡-52、白油和液体石蜡三种增塑剂中,以氯化石蜡-52与SPU的相容性最好、增塑效率最高;当氯化石蜡-52用量为10份时,密封胶拉伸强度为1.65 MPa、断裂伸长率为335%、邵A硬度为37。     

聚丁二烯改性端硅烷化单组分聚氨酯密封胶

安徽大学研究者选择聚醚多元醇、端羟基聚丁二烯、甲苯二异氰酸酯、γ-氨丙基三乙氧基硅烷等为主要原料，在制出聚氨酯预聚物之后，又添加助剂与填料，最终制得单组分湿固化聚氨酯密封胶。由于采用聚丁二烯改性和端硅烷化两项工艺革新，促使该胶的表干时间延长，粘接性能提高，拉伸强度有所增进，断裂伸长率降低。该胶拓展了聚氨酯胶粘剂的实用领域，市场前景较佳。     

蒙脱土与有机硅共改性聚氨酯型密封胶的研究

采用2,4-甲苯二异氰酸酯(TDI)、聚醚多元醇、纳米有机蒙脱土(OMMT)、α,ω-二羟基聚二甲基硅氧烷和硅烷偶联剂为原料,制备了蒙脱土和有机硅复合改性的硅烷化聚氨酯(SPU)密封胶。研究了有机硅和OMMT用量、填料、催化剂的种类及用量对SPU密封胶力学性能的影响。采用X射线衍射和红外光谱对预聚体进行了表征,研究表明,经有机化处理的蒙脱土和有机硅复合改性的SPU密封胶具有性能互补效果,能同时提高密封胶的拉伸强度和伸长率。比纯SPU密封胶分别提高了72.5%和73.2%。     

密封胶用硅烷封端聚醚树脂的制备与性能研究

以3-异氰酸酯基丙基二甲氧基硅烷、聚丙二醇(PPG)、N-(β-氨乙基)-γ-氨丙基三甲氧基硅烷为主要原料,通过加成反应制备了不同异氰酸酯基与羟基的量之比(R值)的硅烷封端聚醚树脂.采用红外光谱和核磁共振氢谱表征了产物结构,并测试了其固化物性能.结果表明,随着R值的增大,硅烷封端聚醚树脂固化物的拉伸强度从0.29 MP...     

一种硅烷封端聚氨酯的合成及其在密封胶制备中的应用

设计了一种不同于以往同类型硅烷封端聚氨酯（SPU）预聚体的合成方案。以一种端—NCO硅烷和端—OH聚氨酯预聚体封端反应，得到硅烷封端聚氨酯预聚体。然后以此为基料，并添加催化剂和补强填料，通过配方筛选，制备了一种弹性密封胶产品。研究结果表明：当以MDI-100制备的产品作为调胶基料，以KH-540作为偶联剂，选择使用改性有机锡催化剂，w（纳米碳酸钙）=25%,w（疏水性白炭黑）=2%（相对于总质量而言）时，制备的密封胶综合性能较优。该密封胶克服了聚氨酯和硅酮密封胶的缺点，具有湿气固化特性，胶层不起泡、弹性好、可涂饰，综合性能优异，并且合成过程简单易控，产物稳定，目前已在工程密封领域得到了应用。     

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。