双固化聚氨酯丙烯酸酯的性能研究

将三种双固化聚氨酯丙烯酸酯低聚物与环氧丙烯酸酯组成不同的双固化体系,利用实时红外(FT-IR)的方法研究了不同固化顺序(先光固化后热固化和先热固化后光固化)对体系中-NCO反应基团和C=C双键转化率的影响,结果显示先光固化后热固化的固化顺序更有利于体系达到高转化率.通过测试不同体系固化后的硬度和柔韧性,证明后期的热固化能大幅度提高涂膜的硬度.     

光固化体系对环氧树脂固化及性能的影响

研究了两种光引发剂（硫Ｗｅｎｇ盐、铁配合物）与活性稀释剂地Ｅ４４光固化反应及产物性能的影响。结果表明：光引发活性是硫Ｗｅｎｇ盐〉铁配合物，知量的活性释释剂能加速Ｅ４４的固化，活性释剂的加入能改善固化产物的脆性，双烯醚的增韧效果最佳。     

功能性光活性稀释剂的合成及光固化性能研究

研究了含有嗯唑烷酮单元的新型光活性单体的合成及结构表征,考察了反应条件对产物结构的影响.以实时红外光谱法研究了新型光活性稀释剂、复配胶的光聚合行为,结果表明合成的新单体具有很高的光固化活性.还对所配胶的光固化时间、光固化膜的硬度、耐冲击性、凝胶率等性能进行了研究,考察了胶的组成对紫外光固化膜性能的影响.     

不饱和聚酯树脂的紫外光固化研究

通过红外光谱分析,凝胶转化率测定及力学性能测试研究了不同光引发剂(安息香双甲醚(DMPA),2-羟基-2-甲基苯基丙酮(HMPP)和二苯甲酮/三乙胺(BP/TEA))和不同配比稀释剂(苯乙烯(ST)和甲基丙烯酸甲酯(MMA))对不饱和聚酯光固化体系性能的影响。结果表明,质量分数1%的DMPA拥有较高的光引发活性,适合作为UP/ST/MMA体系的光引发剂,当m(ST)/m(MMA)=9∶1时,固化物冲击强度和弯曲强度达到最大,分别为17.33 k J/m2和168.3 MPa,拉伸强度则在m(ST)/m(MMA)=6∶4时达到最大值65.8 MPa。     

紫外光固化环氧丙烯酸酯的贮存稳定性

为制备贮存稳定性优良的紫外光(UV)固化涂料,采用自制改性环氧丙烯酸酯树脂、活性稀释剂、光引发剂和阻聚剂制备了UV固化涂料体系并通过考察50°C下贮存7 d前后黏度的变化,研究了活性稀释剂、光引发剂和阻聚剂种类及用量对贮存稳定性的影响,并确定了最优体系:活性稀释剂w(己二醇二丙烯酸酯)=20%~30%,光引发剂w(Darocur 11733)=3.0%,阻聚剂w(对羟基苯甲醚)=0.04%。用红外光谱、凝胶渗透色谱等对贮存前后的体系进行了表征。测试了以最优体系为基础配制的UV涂料的涂膜性能。结果表明,加速贮存7 d后,涂料体系的重均分子量和数均分子量分别增加393 g/mol和403 g/mol,C═C双键含量仅损失4.9%,可见涂料具有较好的贮存稳定性,其漆膜性能与贮存前相比并无差异。     

乙烯基醚活性稀释剂在环氧丙烯酸树脂紫外光固化中的应用

运用红外光谱法研究环氧丙烯酸树脂紫外光固化过程中体系中双键的转化率，发现体系的粘度和活性稀释剂的反应活性同时影响固化过程中双键的转化率，当体系的粘度为Cp，活性稀释剂TMPTA／DVE-3(质量比)=1：1时，双键的转化率最大。当体系的粘度为Cp，活性稀释剂TMP-TA／(DVE-3 CHVE)(总质量比)=1：1时，双键的转化率最大。同时发现在，部分加入乙烯基醚的固化产物，具有优异的表面硬度和光泽度。     

活性稀释剂对环氧豆油丙烯酸酯光固化体系的影响

用环氧豆油与丙烯酸反应制备出环氧豆油丙烯酸酯预聚物,研究了活性稀释剂的组成、配比对紫外光固化速率、固化膜性能及施工性能的影响,并利用红外光谱对涂料光固化前后的结构进行了表征。结果表明:活性稀释剂的加入量以30%为宜,当其配比为10%苯乙烯,20%三羟甲基丙烷三丙烯酸酯时,光固化速率较快,固化膜无色透明,表面光滑平整,其硬度达到3H,且具有较好的柔韧性和附着力。     

紫外光固化EFOA-HDDA-EA共聚体系的动力学研究

通过测定凝胶含量,对由环氧全氟辛酸酯丙烯酸酯、1,6-己二醇双丙烯酸和环氧丙烯酸酯组成的光固化体系[即P(EFOA-HDDA-EA)]进行了动力学研究,得到紫外光聚合速率与光引发剂的活性和浓度、光敏性单体的用量、活性稀释剂的种类、涂膜厚度等因素之间的关系,证明了P(EFOA-HDDA-EA)光聚合体系的单体转化率比P(EFOA-TMPTA-EA)光聚合体系(TMPTA即三羟甲基丙烷三丙烯酸酯)的单体转化率大,裂解型自由基引发剂2-羟基-2-甲基-1-苯基-1-丙酮(HMPP)时光固化EFOA-HDDA-EA共聚树脂体系的引发效果优于二苯甲酮/三乙胺引发体系.     

多官能度UV固化松节油基聚氨酯丙烯酸酯的研究

以三羟甲基丙烷(TMP)、环氧丙醇及自制的松节油-马来酸酐(TMA)为原料,制备含有6个端羟基的聚酯,再以甲苯-2,4二异氰酸酯(TDI)、丙烯酸羟丙酯(HPA)进行封端,得到可UV固化的多官能度聚氨酯丙烯酸酯(PUA)。采用红外光谱(FT-IR)分别对制备出的聚酯及PUA进行了表征,并应用力学性能测试、热重分析考察了活性稀释剂种类及用量对固化涂膜物理性能和热性能的影响。结果表明:采用二丙二醇二丙烯酸酯(DPGDA)和三羟甲基丙烷三甲基丙烯酸酯(TMPTMA)复配活性稀释剂,m(DPGDA)∶m(TMPTMA)=4∶1,添加质量分数为20%时,固化膜综合性能较佳,固化膜初始分解温度约为245℃,另1分解温度约为390℃,耐热性能较好;利用凝胶法研究PUA的光固化行为表明其不饱和双键的最终转化率高达92%。     

印刷纸张用紫外光固化水性上光油的制备研究

研究了纸张用紫外光(UV)固化水性上光油低聚物共聚单体的配方、引发剂种类和用量及反应条件,合成了水性上光油低聚物,在此基础上与活性稀释剂、光引发剂等复合制备了纸张用紫外光固化水性上光油,研究了其组成和性能指标,优化出了光固化速率适宜、性能良好的水乳性紫外固化涂料。研究结果表明:当该复合涂料中光引发剂2959的用量为3%、活性稀释剂的质量为乳液质量的40%、附着力促进剂含量为0.6%时涂层光固化时间最短,涂膜综合性能最好。最终制得了光泽度佳、光滑、耐磨、紫外固化速率较快的水性上光油。     

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.     

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.     

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。     

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.