丙烯酸酯改性ANGE-PCDL型WPUA的合成与表征

以丙烯海松酸新戊二醇酯(ANGE),聚碳酸酯二元醇(PCDL)、丙烯酸/3-AE丙Al-( HPA)、异佛尔酮二异氰酸酯(IPDI)、二劲甲基丙酸(DMPA)为主要原料,制备了ANGE-PCDL型水性聚氨酯分散体(WPU);滴加丙烯酸酯单体到WPU中,得到了PCDL-ANGE型水性聚氨酯-丙烯酸酯复合乳液(WPUA)....     

丙烯酸酯改性磺酸型水性聚氨酯乳液的合成及性能研究

以甲苯二异氰酸酯(TDI-80)、聚酯二元醇为主要原料,1,4-丁二醇(BDO)为小分子扩链剂,丙烯酸羟乙酯(HEA)为封端剂,乙二胺基己磺酸钠(N60)为亲水扩链剂,成功制备了封端型水性聚氨酯乳液(WPU)。再以甲基丙烯酸甲酯(MMA)和丙烯酸丁酯(BA)对上述乳液进行接枝共聚,成功制备出丙烯酸酯-水性聚氨酯复合乳液(WPUA)。通过红外(FTIR)、透射电镜(TEM)、热重分析(TGA)、耐水性和力学性能测试等分析手段研究了WPUA乳液及其涂膜的结构与性能。结果表明,WPUA乳液具有良好的室温贮存稳定性及成膜性能,与WPU乳液相比,WPUA乳液粒径有所增大,且粒子呈核壳结构。其胶膜的耐热性、耐水性和力学性能较WPU胶膜均有所提高。     

环保型抗起毛起球整理剂KD-1的合成与应用研究

研究合成聚氨酯丙烯酸酯结构的聚合乳液,用于涤/棉化纤织物的抗起毛起球整理,确定了较佳的合成工艺参数及整理工艺.经KD-1整理后的织物抗起毛起球等级可达到4～5级,手感较佳,该整理剂为无甲醛整理剂,符合环保要求.     

聚氨酯-聚丙烯酸酯共聚乳液的制备及形态研究

以聚醚二元醇(GE-210)、异佛尔酮二异氰酸酯(IPDI)和二羟甲基丙酸(DMPA)为主要原料,制备了水性聚氨酯(WPU)乳液;再采用丙烯酸丁酯(BA)和甲基丙烯酸甲酯(MMA)与WPU乳液共聚制备水性聚氨酯-聚丙烯酸酯(WPUA)复合乳液。讨论了WPUA乳液及胶膜的性能,并采用FT-IR、XRD、SEM和AFM等分析手段研究了WPUA涂膜的结构和形貌。结果表明,WPUA乳液具有良好的室温贮存稳定性及成膜性能,胶膜为无定型结构,透光率90%。与WPU乳液相比,WPUA乳液粒径有所增大,对基材的浸润性更好;其胶膜耐水性能明显提高;SEM和AFM分析同时显示,WPUA胶膜微观呈现"脊-谷"结构。     

水性聚氨酯-丙烯酸酯复合乳液的性能研究

用丙烯酸酯改性水性聚氨酯制备了具有核壳结构的水性聚氨酯-丙烯酸酯(WPUA)复合乳液,系统地研究了水性聚氨酯(PU)含量、nNCO/nOH(初始物质的量比)、亲水性扩链剂二羟甲基丙酸(DMPA)用量及软硬单体质量比对WPUA乳液及其膜的性能的影响.结果显示,WPUA乳液胶粒呈核壳型结构,聚丙烯酸酯(PA)与PU链段具有...     

丙烯酸酯类低聚物改性水性聚氨酯压敏胶的性能研究

以聚醚多元醇和IPDI(异佛尔酮二异氰酸酯)为主要原料,以自制的DJW-330(丙烯酸酯类低聚物)为WPU(水性聚氨酯)乳液的化学改性剂,采用自乳化法合成了性能良好的改性WPUA(水性聚氨酯丙烯酸酯)乳液。结果表明:当R=n(-NCO)/n(-OH)=0.95、w(DJW-330)=1.4%时,改性WPUA乳液的稳定性较好,其粒径分布变宽,耐热性略高于未改性WPU乳液;由于DJW-330与WPU分子间是以化学键的形式结合,故此时改性WPUA压敏胶的初粘力(14#号球)、持粘力(100 min)和180°剥离强度(5.38 N/cm)同时达到最大值。     

丙烯酸酯用量对溶胀-嵌段型水性聚氨酯性能的影响

以甲基丙烯酸甲酯(MMA)、丙烯酸正丁酯(BA)为单体,通过巯基乙醇链转移自由基无规共聚合成端羟基聚丙烯酸酯(PA-OH),采用嵌段共聚法将PA-OH与水性聚氨酯(WPU)嵌段,通过预聚体分散法制得聚丙烯酸酯嵌段水性聚氨酯乳液(WPUA),进而通过乳液聚合法制备了一系列以MMA/BA为单体的聚丙烯酸酯嵌段-溶胀水性聚氨酯复合乳液(WPUA-PA),结果表明WPUA-PA中丙烯酸酯量最多可达到WPUA的240%,当丙烯酸酯量为WPUA的120%时WPUA-PA的性能最佳,此时乳液平均粒径为68 nm、粒径分布指数为0.174,胶膜拉伸强度为13.88MPa、断裂伸长率为558.3%、吸水率为4.94%,且具有优异的乳液稳定性。     

功能化石墨烯改性无胺型水性聚氨酯的制备

以聚己内酯二元醇(PCL)、甲苯二异氰酸酯(TDI)、甲基丙烯酸甲酯(MMA)为主要原料,合成水性聚氨酯-丙烯酸酯乳液(WPUA)预聚体。将偶联改性的纳米SiO_2与氧化石墨烯进行接枝后,与聚氨酯-丙烯酸酯乳液预聚体进行原位聚合,用自乳化法制备了经功能化石墨烯改性的无胺型水性聚氨酯-丙烯酸酯复合乳液(SiO_2-NH_2-GO/WPUA),对功能化石墨烯的用量进行讨论,并对其复合乳液、胶膜结构及性能进行测试。与水性聚氨酯-丙烯酸酯(WPUA)相比,SiO_2-NH_2-GO/WPUA具有更好的耐温性及胶膜性能,当氧化石墨烯接枝SiO_2(SiO_2-NH_2-GO)质量分数为0.75%时,复合乳液胶膜较未改性乳液胶膜相比,热分解温度提高14.51℃;拉伸强度提高到81.28 MPa;该复合乳液配制的胶黏剂在铝箔/PVC薄膜的T-剥离强度达到15.4 N;易氧化物含量指标符合药品包装容器标准,表明该水性聚氨酯胶黏剂适用于医药包装。     

水性聚氨酯-丙烯酸酯的制备及涂膜性能

水性聚氨酯具有良好的粘结性、弹性、耐寒性、高光泽性等特点,但是单一的WPU乳液耐水性,耐侯性和耐老化性比较差且成本比较高。而水性丙烯酸酯却具有良好耐水性,耐侯性和耐老化性,防腐、耐碱、耐水、成膜性好,保色性佳,无污染等特征。本论文首先通过乳液聚合制备水性丙烯酸酯乳液,在此基础上,用聚丙烯酸酯对聚氨酯进行改性,从而使聚氨酯和聚丙烯酸酯的优势性能得到互补,可以制得性能优异的水性转移涂料用聚氨酯一丙烯酸酯(PUA)复合乳液。并且对其涂膜性能进行了研究。     

聚氨酯型反应性乳化剂改性丙烯酸酯的合成及应用

以低聚物多元醇、异佛尔酮二异氰酸酯、二羟甲基丙酸、甲基丙烯酸β-羟乙酯、三羟甲基丙烷等为原料分别制备直链型和具有一定支化度的水性聚氨酯（WPU）。以合成的WPU作为大分子型反应性乳化剂,再辅以少量乳化剂DNS-86与丙烯酸酯单体热引发聚合,制得聚氨酯-丙烯酸酯乳液（PUA）。通过红外光谱和粒径分析等方法对PUA的结构及性能进行表征。结果表明：与直链型相比,经过支链型PU改性后的成膜物拉伸强度达到23.3MPa,粘合剂的皂洗牢度等级达到4级,干摩擦牢度达到4级,湿摩擦牢度达到3级。     

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.     

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.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.