含氟水性聚氨酯-丙烯酸酯涂料的制备及其成膜强度和耐水性的研究

采用原位乳液聚合法,合成了含氟自交联型水性聚氨酯-丙烯酸酯(FPUA)乳液.研究了单体物质的量比、环氧基团含量和氟单体含量对乳液制备过程、乳液及涂膜性能的影响.通过红外光谱、热重分析对其结构和膜性能进行表征,并对涂膜表面的水接触角进行了研究.结果表明:n(—NCO)∶n(—OH)=1.4、n(—NHNH2)∶n(—CO—)=1、GMA用量为4％、含氟单体用量为6％时,合成乳液稳定性良好,涂膜的耐水性和热稳定性良好.在成膜时复合乳液中的氟基团向空气/聚合物界面伸展,有效地覆盖涂膜表面,降低涂膜表面能,水在涂膜上的接触角达到117.2°.     

阳离子型水性UV固化含氟聚氨酯树脂的制备及性能研究

以二乙醇胺、甲基丙烯酸十三氟辛酯为原料,通过迈克尔加成反应合成一种含氟二元醇(F-DEA),并以此为含氟单体,通过缩合共聚的方法与异佛尔酮二异氰酸酯(IPDI)、聚四亚甲基醚二醇(PTMG-1000)、N-甲基二乙醇胺(MDEA)以及季戊四醇三丙烯酸酯(PETA)反应合成一种阳离子型水性UV固化含氟聚氨酯树脂。利用FT-IR、1H-NMR等手段对产物的分子结构进行表征。采用粒径分析、接触角、X射线光电子能谱(XPS)以及各种性能测试手段,对乳液、光固化过程及涂膜性能进行分析研究。结果表明:在一定条件下,该树脂能稳定分散在水中,随着含氟量的增加,乳液粒径增大,但光固化效率有所降低,同时热处理后的氟碳链迁移至涂膜表面,所得的光固化涂膜各种性能较好,特别是耐水和耐酸碱性有明显改善。     

含氟丙烯酸酯乳液合成及其内墙涂料防涂鸦性的研究

以烯丙氧基羟丙基磺酸钠(COPS-1)、壬基酚聚氧乙烯醚硫酸铵(CO-436)和NP-10为复合乳化剂,过硫酸铵为引发剂进行了含氟丙烯酸酯乳液聚合研究,测定不同含氟单体含量制备的乳液干膜及漆膜与水、油的接触角,比较含氟单体含量、不同交联单体及含量对涂膜耐污性能的影响。研究结果表明:随含氟单体含量增加,乳液干膜及涂膜与水、油接触角增大;由12%甲基丙烯酸十二氟庚酯、5%双丙酮丙烯酰胺所合成的含氟丙烯酸酯乳液,稳定性高,耐沾污性好;当乳液含量为涂料配方总量的36%时,涂膜对水彩污迹的耐污性能明显改善,且遮盖力好。     

水性含氟耐候防锈涂料的制备及应用

采用核壳乳液聚合法,并加入磷酸酯功能单体(PAM-100),制备了氟单体用量为5%的含氟丙烯酸酯聚合物乳液。分析了含氟单体、乳化剂、磷酸酯功能单体等因素对乳液合成的影响。用合成的乳液配制了水性防锈涂料,并对其性能进行测试。     

含氟丙烯酸酯乳液高疏水性与低氟含量的平衡探索

为了研究含氟丙烯酸酯乳液涂膜的疏水性与氟含量的平衡关系,以甲基丙烯酸十二氟庚酯(DFHM)为含氟单体,双丙酮丙烯酰胺(DAAM)和己二酸二酰肼(ADH)为交联单体,采用半连续核壳乳液聚合的方法合成了一系列自交联含氟丙烯酸酯共聚物乳液。研究表明:含氟单体含量为12%(即氟含量为6.84%,均以聚合单体的总质量计,下同)时,含氟基团在涂膜表面可以达到饱和,乳液固含量可达38.2%;再添加4%交联单体,涂膜的水接触角为116.6°。当含氟单体含量降为4%(氟含量2.28%)时,通过提高成膜温度或添加成膜助剂,也可使涂膜表面的水接触角达到104.2°,具有较好的疏水性能。     

阳离子型全氟丙烯酸酯无皂乳液的合成及性能

以全氟烷基乙基丙烯酸酯(FEA)为含氟单体,以甲基丙烯酰氧乙基三甲基氯化铵(DMC)为阳离子单体,采用无皂乳液聚合方法合成了阳离子型全氟丙烯酸酯共聚物乳液.分析了FEA含量对涂膜性能的影响,讨论了DMC用量对聚合转化率、涂膜吸水率以及乳胶粒粒径大小的影响;利用FT-IR和X-射线衍射分析(XRD)对共聚物乳液进行了表征,结果表明,当FEA和DMC质量分数分别为7.1%和12%时,涂膜的吸水率最小,仅为3.75%,乳胶粒平均粒径为65 nm.随着FEA量的增加,共聚物膜的硬度减小,拉伸强度增加,断裂伸长率降低;XRD分析显示全氟丙烯酸酯无皂乳液具有好的结晶性.     

核壳型短链含氟丙烯酸酯乳液的合成及表征

该文研究了核壳型短链含氟丙烯酸酯乳液的合成与表征。以甲基丙烯酸甲酯(MMA)和丙烯酸丁酯(BA)的共聚体为核,短氟碳链2-(全氟己基)乙基甲基丙烯酸酯(FMA6)和非氟烷基丙烯酸酯的共聚体为壳,采用多步乳液聚合法,合成系列具有核壳结构的含氟丙烯酸酯乳液,研究了壳相中氟单体用量和非氟烷基丙烯酸酯的烷基链长度n(链长n=4、8、12、16、18)对产物疏水疏油性能的影响,并对产物进行表征。结果表明:当采用氟单体用量为总单体质量的8.5%,甲基丙烯酸十六酯(CMA)的共聚体为壳层时,由合成乳液制得的乳胶膜的疏水疏油性最佳,对水接触角为124.67°,对二碘甲烷接触角为112.76°。FTIR、TEM和DSC/TGA表征表明,原料单体均参加了反应;乳液颗粒具有明显的核壳结构;聚合物存在两个玻璃化温度(-18.87℃和32.08℃),热分解温度比不含氟的聚合物提高了近20℃。由此说明,用合成的核壳型短链含氟丙烯酸酯乳液制得的涂膜具有优异的疏水疏油性和耐热性能。     

导读

彭晨等以含酮基的双键封端的PUA-kt功能单体与甲基丙烯酸甲酯(MMA)、丙烯酸乙酯(EA)等单体共聚合成了聚氨酯丙烯酸酯乳液,再加入一定量己二酸二酰肼,制得室温自交联聚氨酯丙烯酸酯乳液,对聚氨酯丙烯酸酯的合成工艺及性能进行了研究,讨论了乳化剂用量对乳液黏度及凝胶率的影响,PUA-kt对乳液黏度及涂膜交联度的影响,ADH用量对涂膜交联度的影响,并用FTIR、TEM、TGA对聚合物进行     

含磷丙烯酸酯聚氨酯乳液的合成及其性能研究

以聚四氢呋喃二醇(PTMG)、甲苯二异氰酸酯(TDI)、二羟甲基丙酸(DMPA)及丙烯酸β-羟乙酯(HEA)为主要原料合成水性聚氨酯(PU)大单体,得到HEA封端的聚氨酯,加入甲基丙烯酸甲酯(MMA)、磷酸酯功能单体等单体,以半连续乳液聚合法合成了水性含磷丙烯酸酯聚氨酯(P-PUA)。考察了DMPA用量、引发剂用量、丙烯酸磷酸酯单体用量、MMA用量对乳液和涂膜性能的影响。结果表明:DPMA用量、引发剂用量、丙烯酸磷酸酯单体用量、MMA用量分别为预聚体总量6.0%、3.0%~3.5%、5.0%、15.0%时,得到综合性能良好的P-PUA乳液,制得的涂膜附着力1级,涂膜耐水时间550 h,无闪蚀现象。     

含全氟壬烯基丙烯酸酯单体合成及乳液聚合

研究了含全氟壬烯基丙烯酸酯的合成及其聚合反应。以全氟壬烯氧基苯磺酰氯为原料,经酰胺化、酯化得到N-甲基-N-p-全氟壬烯氧基苯磺酰胺基乙基丙烯酸酯(Ⅲ);确定了Ⅲ的较优合成工艺条件为:n(Ⅱ)∶n(丙烯酰氯)=1∶3,室温反应6 h,含氟单体Ⅲ的收率为75.0%;并将Ⅲ与甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)在K2S2O8(KPS)存在下,通过半连续乳液聚合法,制备了含氟丙烯酸酯乳液。用傅里叶变换红外光谱(FTIR)、核磁共振波谱(1HNMR)、质谱(ESI-MS)等对含氟丙烯酸酯单体(Ⅲ)和聚合物乳胶膜的结构进行了表征;考察了乳液的稳定性、Ⅲ的含量对聚合物膜上水接触角的影响。当含氟丙烯酸酯占单体总质量的20%时,水接触角为88.2°。     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009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、环氧树脂、不饱和聚酯树脂)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。     

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.     

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.     

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.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.