纳米SiO_2表面改性及其在WPUA中的应用研究

用γ-甲基丙烯酰氧丙基三甲氧基硅烷(KH-570)对纳米SiO2进行表面改性,通过光固化法制备纳米SiO2/水性聚氨酯丙烯酸酯(WPUA)复合涂膜,考察了纳米SiO2的粒径、改性条件及SiO2和2,2-二羟甲基丙酸(DMPA)用量对涂膜性能的影响。结果表明,当KH-570用量为10%,反应温度为60℃和反应时间为7 h时,对纳米SiO2表面的改性效果最好;采用粒径为56 nm的改性SiO2所制备的WPUA具有优良的性能;当DMPA的质量分数为6.5%～8.0%时,WPUA乳液的稳定性和外观较好;当加入1.0%改性后的纳米SiO2时,WPUA乳液和涂膜的综合性能较佳。     

复合有机硅改性苯丙乳液的性能

以苯乙烯(St)、丙烯酸异辛酯(EA)和丙烯酸丁酯(BA)为主要单体,丙烯酸(AA)为功能单体,十二烷基苯磺酸钠(SDS)和壬基酚聚氧乙烯醚(OP-10)为复合乳化剂,γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH570)、乙烯基三甲氧基硅烷(A-171)和八甲基环四氧硅烷(D4)为有机硅改性剂,通过乳液聚合合成了不同有机硅改性苯丙乳液。研究了复合乳化剂的用量及配比,软硬单体质量比,以及复合有机硅改性剂的配比与用量对苯丙乳液性能的影响,确定了合成有机硅改性苯丙乳液的较佳用量:有机硅的质量分数为6%,软单体(EA、BA)和硬单体(St)的质量比为1∶2,OP-10与SDS的质量比为3∶2,且复合乳化剂的用量为3%。通过红外光谱和热重分析对苯丙乳液,KH570、A-171或D4单一改性以及复合改性苯丙乳液进行了表征,测试了各种乳液及其涂膜的性能。结果表明,有机硅改性后苯丙乳液的综合性能明显提高,复合有机硅改性苯丙乳液的性能最好。当复合有机硅中KH570、A-171和D4的质量比为1∶2∶1时,合成的复合有机硅改性苯丙乳液的固含量为41.33%,粒径80.09 nm,黏度127 mPa·s,其漆膜硬度为2H,吸水率9.34%,失重温度区间在450~520°C,高于苯丙乳液的350~420°C以及由KH-570、A-171或D4单一改性苯丙乳液的390~430°C。     

KH570用量对纳米SiO_2接枝改性的影响

以乙醇和水混合液作为分散介质,采用硅烷偶联剂KH570对纳米二氧化硅(Nano-SiO2)进行接枝改性,制备了KH570接枝改性纳米SiO(2Nano-SiO2-g-KH570)。采用红外光谱、粒度分析及亲油化度测试,研究了KH570用量对Nano-SiO2改性效果的影响。结果表明,以乙醇和水混合液为分散介质,KH570可以对Nano-SiO2进行接枝改性;KH570用量对Nano-SiO2-g-KH570的粒径、粒径分布及亲油化度有明显的影响:KH570用量为5%时,Nano-SiO2-g-KH570的粒径最小,为103nm,粒径分布较窄,亲油化度为32%。     

有机硅改性水性聚氨酯丙烯酸酯的制备及性能

以异佛尔酮二异氰酸酯(IPDI)、聚氧化丙烯二醇(PPG)、二羟甲基丙酸(DMPA)、丙烯酸羟乙酯(HEA)等为原料合成了含双键的聚氨酯乳液,再与有机硅偶联剂KH570、甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)进行自由基聚合,制备了有机硅改性聚氨酯丙烯酸酯(PUA)复合乳液。讨论了KH570用量对PUA胶膜耐水性、耐热性和力学性能的影响,并通过红外光谱、热重分析、粒度分析等测试对其结构和性能进行表征。结果表明,当固体分中KH570质量分数小于7.65%,乳液稳定性良好;随着KH570添加量增大,乳液粒径逐渐增大,胶膜吸水率下降,水接触角增大,耐水性、热稳定性和力学性能得到较大提高。     

硅烷偶联剂改性聚硅氧烷乳液的合成及性能研究

以γ-缩水甘油醚氧丙基三甲氧基硅烷(KH 560)、γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH 570)及八甲基环四硅氧烷(D4)为原料,十二烷基苯磺酸(DBSA)阴离子乳化剂(又作催化剂)与烷基苯酚聚氧乙烯醚(OP-10)非离子乳化剂为复合乳化剂,通过乳液聚合反应合成了性能稳定的改性聚硅氧烷乳液。讨论了KH 560、KH 570及混合单体(KH 560/KH 570)用量对聚硅氧烷乳液粒径及性能的影响。结果表明:随着KH 560用量的增加,乳液粒径逐渐增大,而分布指数先减小后增大。随着KH570用量的增加,乳胶粒粒径先增大后减小,但是粒径分布变窄。两种改性单体同时加入所合成的乳液粒径更大。硅烷偶联剂改性聚硅氧烷乳液耐高温稳定性、耐低温稳定性、离心稳定性及稀释稳定性都良好。加入KH 560单体改性的聚硅氧烷乳液,其在环境温度下成膜效果较佳。     

种子乳液聚合法制备纳米SiO_2/苯丙复合乳液

采用种子乳液聚合工艺,用经硅烷偶联剂改性后的纳米SiO2原位合成了纳米SiO2/苯丙复合乳液。通过正交实验确定了最佳原料配比和聚合工艺条件,并对复合乳液性能进行了分析与表征。结果表明,当功能单体的用量为单体总量的5%、阴离子乳化剂十二烷基硫酸钠(SDS)与非离子乳化剂辛基苯基聚氧乙烯醚(OP-10)质量比为1颐1、复合乳化剂总量3%、纳米SiO2含量为单体总量的1.5%、聚合温度为80℃时,可制备具有良好综合性能的复合乳液,其涂膜耐水性、硬度、附着力等均优于普通苯丙乳液。该复合乳液乳胶粒粒度呈单峰分布,平均粒径为101nm,具有核/壳结构。     

纳米氧化锡锑/UV固化水性聚氨酯隔热涂料的制备及其性能表征

以聚酯二元醇、异佛尔酮二异氰酸酯、二羟甲基丙酸、季戊四醇三丙烯酸酯(PETA)等为原料,制备了具有感光性能的水性聚氨酯丙烯酸酯预聚体(PUA),通过溶胶-凝胶法对采用硅烷偶联剂KH570对纳米氧化锡锑(ATO)进行改性,然后将改性纳米ATO与PUA加水乳化制得纳米WPUA/ATO复合乳液,最后通过UV固化制得WPUA/ATO涂膜,研究了ATO含量对WPUA/ATO涂膜性能的影响。结果表明,随着纳米ATO含量增加,可见光平均透过率降低,红外光平均屏蔽率增加;其中当纳米WPUA/ATO复合乳液中ATO质量含量为9%时,可见光平均透过率为71.43%,红外光平均屏蔽率高达为79.69%,隔热性能较好,特别适合制备涂膜隔热玻璃。     

水性硅溶胶/丙烯酸聚氨酯纳米复合乳液的制备

以异佛尔酮二异氰酸酯(IPDI)、硅溶胶、聚醚二元醇(N210)、二羟甲基丙酸(DMPA)、三羟甲基丙烷(TMP)等为原料,采用原位分散聚合法制备了水性硅溶胶/丙烯酸聚氨酯(SiO2/PUA)纳米复合乳液,研究了硅溶胶、DMPA和TMP的用量以及中和度对SiO2/PUA纳米复合涂层性能的影响,确定了较佳的制备条件:硅溶胶最大添加量为SiO2占SiO2/PUA总固含量的4.5%,DMPA添加量为PUA质量的6.5%,TMP添加量为PUA质量的1.25%,中和度控制在90%。在此条件下制备的SiO2/PUA纳米复合涂层与市售PUA涂膜相比,其硬度、附着力、耐水性、耐溶剂性等都得到一定程度的提高。     

硅溶胶/有机硅改性丙烯酸树脂复合材料的制备

以有机硅KH570为偶联剂,采用溶液聚合法,将其与硅溶胶同时加入到丙烯酸及其酯类单体的聚合过程中,利用有机硅的架桥作用将硅溶胶接枝到丙烯酸树脂分子上,得到稳定的硅溶胶/有机硅改性丙烯酸树脂复合材料(SSPA)。研究了有机硅种类及其用量、硅溶胶用量对SSPA性能的影响,通过红外光谱对其结构进行了表征,测试了改性前后丙烯酸树脂的粒径分布。结果表明,硅溶胶通过有机硅成功接枝到丙烯酸树脂分子上,最佳的制备工艺条件为硅溶胶添加量[m(SiO2)/m(单体)]为4%,m(KH570)/m(SiO2)=5%。用硅溶胶和有机硅改性后得到的SSPA平均粒径增大,分散性变好,涂膜的硬度、冲击强度和附着力等性能都有所提高。     

硅溶胶/有机硅改性丙烯酸酯聚氨酯复合材料的制备

以有机硅KH570为偶联剂,把硅溶胶引入到丙烯酸酯聚氨酯(PUA)中,采用原位分散聚合法制备了硅溶胶/有机硅改性丙烯酸酯聚氨酯(SPUA)复合材料,研究了KH570和硅溶胶的添加量以及硅溶胶与有机硅/丙烯酸酯聚氨酯的反应时间对SPUA复合材料平均粒径、附着力、硬度、耐水性和耐醇性的影响,获得了较佳的反应条件:KH5707.0%,硅溶胶5.5%,反应时间3h。通过红外光谱对较佳条件下制备的SPUA复合材料进行了表征,并与市售产品进行了综合性能对比研究。结果表明,SPUA复合材料出现了N─H弯曲振动吸收峰2046cm1,游离态N─H键的产生说明PUA的N─H键在有机硅的作用下产生电子偏移;硅溶胶的Si─O─H伸缩振动吸收峰从原来的3568cm1处移到了复合后的3442cm1处,且峰变宽,吸收强度变大,说明硅溶胶通过与有机硅作用接枝到PUA分子上。与市售产品比较,SPUA复合材料的硬度、附着力、耐水性和耐醇性等性能更好。     

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.     

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。     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。     

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.