氟聚合物改性聚丙烯酸酯乳液的制备

氟聚合物改性聚丙烯酸酯乳液的制备;氟改性;聚四氟乙烯;聚丙烯酸酯乳液     

有机硅聚丙烯酸酯微乳液的合成与性能

有机硅聚丙烯酸酯微乳液的合成与性能;硅氧烷     

含氢聚甲基硅氧烷/丙烯酸丁酯/羟甲基丙烯酰胺复合乳液的制备方法对乳液性质的影响

采用自由基引发剂用３种不同的聚合方法制备了新型的含氢聚甲基硅氧烷（ＰＨＭＳ）／丙烯酸丁酯（ＢＡ）／羟甲基丙烯酰胺（ＮＭＡ）复合聚合物乳液。详细讨论了不同聚合方法对乳液稳定性和乳胶粒子的影响，同时对聚合反应的机理、产物的结构作了考察．结果表明：通过乳液聚合，得到了ＰＨＭＳ／ＢＡ／ＮＭＡ共聚物；单体乳液滴加法所得乳液粒径较小，乳液性能稳定，是制备ＰＨＭＳ／ＢＡ／ＮＭＡ复合聚合物乳液较适宜的方法．     

有机硅核-壳型聚丙烯酸酯乳液的合成及油田固砂性能研究

有机硅核-壳型聚丙烯酸酯乳液的合成及油田固砂性能研究;聚丙烯酸酯乳液;有机硅改性;固砂;渗透率     

一次加料法合成有机硅复合乳液

采用一次加料法合成了含氢聚甲基硅氧烷／丙烯酸丁酯／羟甲丙烯酰胺复合乳液,探讨了ＰＨＭＳ,引发剂用量和反应温度对反应速率,聚合稳定性、乳液粒长和成膜性的影响,得到了该反应的表观活化能Ｅａ＝１３２．７７Ｋｊ／ｍｏｌ及Ｒｐ∝「ＰＨＭＳ」＾１．３９「ＡＰＳ」＾０．８３,所得乳液具有优良的性能。     

硅氧烷表面改性聚醚酯聚酰亚胺的研究

通过两种方法。即将γ-氨丙基封端的聚二甲基硅氧烷和对氨基苯甲酸酯封端的聚(四亚甲基)醚与均苯四甲酸二酐共缩聚,和将两种预制的聚酰胺酸溶液共混,合成了一组硅氧烷改性的聚醚酯聚酰亚胺材料。ESCA能谱和表面水接触角测量研究材料的表面性质发现,硅氧烷在材料表面富集,对聚醚酯聚酰亚胺材料具有显著的表面改性作用,硅氧烷改性的聚醚酯聚酰亚胺,其热稳定性能和气体透过性能有一定程度的提高,但抗张强度和介电性能有所降低。     

反应加工体系PVC/PHMS的转矩流变性能研究(Ⅰ)

含氢聚甲基硅氧烷;聚氯乙烯;反应加工体系PVC/PHMS的转矩流变性能研究(Ⅰ)     

聚丙烯酸酯改性水性聚氨酯的制备

在回顾聚丙烯酸酯改性水性聚氨酯的研究历史基础上，系统地介绍了聚丙烯酸酯改性水性聚氨酯乳液（PUA）的制备方法，其中包括聚氨酯（PU）和聚丙烯酯（PA）的直接掺混法、PU和PA的乳液共聚法，接枝法，互穿网络法，核壳聚合法，对这些方法做了简单的评述，对其应用范围及前景进行了初步探讨。     

核壳型聚丙烯酸酯乳胶粒子及其乳液的研究进展

综述了目前制备核壳型聚丙烯酸酯乳胶粒子的常用方法,如种子乳液聚合法、无皂乳液聚合法、反相乳液聚合法、细乳液聚合法以及种子分散聚合法;分析了聚合工艺、单体种类、温度、乳化剂和引发剂种类及用量等因素对聚丙烯酸酯核壳乳液合成及性能的影响;并对聚丙烯酸酯核壳乳液的研究现状进行了归纳;最后,展望了聚丙烯酸酯核壳乳液的发展方向。     

聚氨酯/聚丙烯酸酯复合乳液的研制进展

概述聚氨酯－聚丙烯酸酯复合乳液的制备方法。特别对聚氨酯－聚丙烯酸酯复合乳液共聚法作了较为系统的介绍和讨论。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.