UV固化改性蓖麻油基水性聚氨酯的制备及抗菌性能

以蓖麻油(CO)、异佛尔酮二异氰酸酯(IPDI)、阳离子扩链剂N-甲基二乙醇胺(MDEA)、封端剂甲基丙烯酸羟乙酯(HEMA)为主要原料,制备一系列紫外(UV)固化型蓖麻油基水性聚氨酯(UWPU)乳液.为进一步提升其抗菌性能,通过引入胍基的方法,制备出抗菌型UV固化蓖麻油基水性聚氨酯(GWPU)乳液.通过耐水性、抑菌圈、抗菌性能测试对制得胶膜性能进行了检测.结果表明,GWPU胶膜相对UWPU吸水率有所上升,但均保持在10％以下;GWPU胶膜抗菌方式为接触性杀菌,同时不具有浸出性;当氨基胍盐含量为UWPU胶膜质量的1.2％时,GWPU对金黄色葡萄球菌(S.aureus)、大肠杆菌(E.coli)的抗菌率均可达99.9％,且经过10 d抗菌测试后仍能保持99.9％的抗菌性.     

UV固化改性蓖麻油基水性聚氨酯的制备及抗菌性能

以蓖麻油(CO)、异佛尔酮二异氰酸酯(IPDI)、阳离子扩链剂N-甲基二乙醇胺(MDEA)、封端剂甲基丙烯酸羟乙酯(HEMA)为主要原料,制备一系列紫外(UV)固化型蓖麻油基水性聚氨酯(UWPU)乳液.为进一步提升其抗菌性能,通过引入胍基的方法,制备出抗菌型UV固化蓖麻油基水性聚氨酯(GWPU)乳液.通过耐水性、抑菌圈、抗菌性能测试对制得胶膜性能进行了检测.结果表明,GWPU胶膜相对UWPU吸水率有所上升,但均保持在10％以下;GWPU胶膜抗菌方式为接触性杀菌,同时不具有浸出性;当氨基胍盐含量为UWPU胶膜质量的1.2％时,GWPU对金黄色葡萄球菌(S.aureus)、大肠杆菌(E.coli)的抗菌率均可达99.9％,且经过10 d抗菌测试后仍能保持99.9％的抗菌性.     

UV固化改性蓖麻油基水性聚氨酯的制备及抗菌性能

以蓖麻油(CO)、异佛尔酮二异氰酸酯(IPDI)、阳离子扩链剂N-甲基二乙醇胺(MDEA)、封端剂甲基丙烯酸羟乙酯(HEMA)为主要原料,制备一系列紫外(UV)固化型蓖麻油基水性聚氨酯(UWPU)乳液.为进一步提升其抗菌性能,通过引入胍基的方法,制备出抗菌型UV固化蓖麻油基水性聚氨酯(GWPU)乳液.通过耐水性、抑菌圈、抗菌性能测试对制得胶膜性能进行了检测.结果表明,GWPU胶膜相对UWPU吸水率有所上升,但均保持在10％以下;GWPU胶膜抗菌方式为接触性杀菌,同时不具有浸出性;当氨基胍盐含量为UWPU胶膜质量的1.2％时,GWPU对金黄色葡萄球菌(S.aureus)、大肠杆菌(E.coli)的抗菌率均可达99.9％,且经过10 d抗菌测试后仍能保持99.9％的抗菌性.     

UV固化PHMG基抗菌非离子水性聚氨酯的制备与性能

通过乙二胺（GHC）和盐酸胍（GHC）熔融缩聚制备了抗菌剂聚六亚甲基胍盐酸盐（PHMG），将PHMG与甲基丙烯酸缩水甘油酯（GMA）反应制得双键官能化PHMG（MPHMG），通过FTIR、1H NMR、13C NMR和UV表征了MPHMG的成功合成；将MPHMG、光引发剂和双键封端非离子水性聚氨酯（NU）共混，待水挥发后经紫外固化得到抗菌涂层PNU。通过FTIR、TGA、拉伸、吸水率和抗菌性能测试对PNU胶膜的结构与性能进行了表征。结果表明，MPHMG会增加PNU胶膜中软段的氢键作用和亲水基团含量，当胶膜中MPHNG含量为2.0%时，其T30%和T50%分别提高了7.3℃和12.6℃，拉伸强度提高了1.6MPa，吸水率增加了6.8%。抗菌试验表明，当胶膜中MPHMG的含量大于1.0%时，接触细菌2h，对金黄色葡萄球菌和大肠杆菌的抗菌率均可以达到99.8%以上。     

马来酸酐改性蓖麻油制备交联型水性聚氨酯

以马来酸酐与蓖麻油制备含碳碳双键的三羧基蓖麻油(MACO)作为内交联剂,合成改性蓖麻油水性聚氨酯乳液(MACO-WPU)。采用FT-IR和XRD对改性聚氨酯的结构进行表征,证实MACO被成功引入到聚氨酯大分子链中且分子链呈现无序状态。通过对力学性能、吸水率、粒径、热重分析等研究了MACO用量对聚氨酯乳液及胶膜性能的影响,结果表明:当w(MACO)=3%时,乳液外观和稳定性好,平均粒径为48.45 nm; 胶膜的拉伸强度和断裂伸长率分别为13.15 MPa、195%;与未改性WPU相比热稳定性略有提高。     

PDMS改性蓖麻油基水性聚氨酯的制备及防污性能

本研究以低成本的二甲基二甲氧基硅烷为主要原料，通过水解缩合反应制备合成了聚二甲基硅氧烷（PDMS），进而将其引入蓖麻油基水性聚氨酯（CWPU-SOP）中制备了具有防污性能的蓖麻油基水性聚氨酯(PDMS/CWPU-SOP)。结果表明，当PDMS引入量为8%时，与CWPU-SOP薄膜相比，PDMS/CWPU-SOP薄膜接触角提高了25?，达110?，PDMS/CWPU-SOP薄膜的吸水率下降了7%，为15%；PDMS提高了薄膜疏水性和耐水性。PDMS/CWPU-SOP薄膜在不同酸碱性的液滴在其表面可自由滚落且不留痕迹，具有一定的防污性能。     

蓖麻油改性巯基-烯UV固化水性聚氨酯分散体的制备

采用自乳化聚氨酯水分散体的制备方法,分别制备了含蓖麻油基和巯基的聚氨酯水分散体.将两者按一定比例复合,加入水性光引发剂,在紫外光照射下,通过水性光引发剂引发涂层中的双键及巯基进行巯基-烯点击反应,制得交联聚氨酯涂膜.采用核磁共振氢谱、红外光谱、差示扫描量热仪、热重分析等手段对水分散体及光固化涂膜的结构和性能进行了分析表征.结果表明:巯基和蓖麻油结构中的碳碳双键成功地引入到了水性聚氨酯链段中;在紫外光辐照下,巯基和不饱和双键间进行了加成反应;UV固化膜具有良好的机械性能和热稳定性:凝胶量为96.67％、胶膜吸水率为13.0％、耐冲击性大于50 cm、硬度为5H、耐溶剂(甲乙酮)拭擦次数为734次、失质量50％时的温度为375 ℃.     

玻璃纤维浸润剂用聚氨酯的制备

采用异氟尔酮二异氰酸酯与聚酯二元醇为主要原料,以二羟甲基丙酸(DMPA)为亲水扩链剂,以乙二胺为小分子扩链剂,采用预聚体法合成了可以应用于玻纤浸润剂中的阴离子水性聚氨酯。考察了异氰酸根指数R、DMPA、蓖麻油及扩链剂的用量对水性聚氨酯及胶膜性能的影响,得出了制备蓖麻油改性阴离子型水性聚氨酯的最佳配方,并将其应用在玻纤中。     

三嗪基含氟扩链剂改性水性聚氨酯的合成

利用三聚氰氯（CC）、八氟戊醇（OFP）和乙醇胺（MEA）间的反应先合成了三嗪基含氟扩链剂CC-F，在此基础上制备出系列三嗪基含氟扩链剂改性水性聚氨酯CC-FPUF。利用FTIR和1HNMR对其结构进行表征，并用DLS、XRD、XPS、SEM、WCA和电子万能试验机探究了CC-FPUF制备中所用CC-F的含量(以CC-F、IPDI、CMA-1044、DMPA、S104、TMP和TEA的总质量为基准，下同）对CC-FPUF的乳液粒径、聚合物形态、胶膜形貌、表面元素组成、疏水性能和力学性能的影响。结果表明，随着CC-F含量的增加，CC-FPUF的乳液粒径、胶膜疏水性能和胶膜拉伸强度均有所增加。当CC-F的含量达到8%（CC-FPUF-8）时，胶膜的水接触角最高达到125.8°，相比不含氟的水性聚氨酯（PU）和CC-FPUF-0（CC-F的含量为0）分别增加了60.9°和34.1°；此时胶膜的拉伸强度最大，相比CC-FPUF-0增加了24.47 MPa。胶膜CC-FPUF-8表现出优异的疏水性能和良好的力学性能。     

磺酸型扩链剂用量对WPU胶膜性能影响的研究

以聚四氢呋喃二醇(PTMG1000)、异佛尔酮二异氰酸酯(IPDI)和自制液态磺酸型扩链剂1,2-二羟基-3-丙磺酸(DHPS)为原料合成预聚体,以四甲基氢氧化铵(TMAH)为成盐剂,改变DHPS用量制备了一系列水性聚氨酯乳液,利用动态力学分析(DMA)、热重分析(TGA)、拉伸等测试方法对聚氨酯胶膜性能进行了研究。结果表明,随着DHPS用量的增加,聚氨酯胶膜的拉伸强度增大,断裂伸长率降低。当磺酸基质量分数为4%时,聚氨酯胶膜的拉伸强度为40.4 MPa、断裂伸长率为1006%。随着磺酸基含量的增加,聚氨酯胶膜的硬度增加,耐水性降低,耐溶剂性增加。     

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.