共查询到20条相似文献,搜索用时 15 毫秒
1.
Ding Wang Ye Liu Chun‐Yan Hong Cai‐Yuan Pan 《Journal of polymer science. Part A, Polymer chemistry》2005,43(21):5127-5137
Novel hyperbranched poly(amido amine)s containing tertiary amines in the backbones and acryl as terminal groups were synthesized via the Michael addition polymerizations of trifunctional amines with twofold molar diacrylamide. The hyperbranched structures of these poly(amido amine)s were verified by 13C NMR (INVGATE). The polymerization mechanisms were clarified by following the polymerization process with NMR method, and the results show that the reactivity of secondary amine formed in situ is much lower than that of the secondary amine in 1‐(2‐aminoethyl) piperazine (AEPZ) ring and the primary amine. The secondary amine formed in situ was almost kept out of the reaction before the primary and secondary amines in AEPZ were consumed, leading to the formation of the AB2 intermediate, and the further reaction of the AB2 yielded the hyperbranched polymers. The molecular weights and properties of poly(amindo amine)s obtained were characterized by GPC, DSC, and TGA, respectively. Based on the reaction of active acryl groups in the polymers obtained with glucosamine, hyperbranched polymers containing sugar were formed. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5127–5137, 2005 相似文献
2.
Hyperbranched poly(amido amine)s (HPAA) show weak photoluminescence, however, they have shown strong emission after short polyethylene glycol (PEG) chains have been linked onto HPAA macromolecule via Michael addition reaction. These PEGylated hyperbranched poly(amido amine)s show low cytotoxicity and potential application in cell imaging. 相似文献
3.
Jae Wook Lee Hee Joo Kim Seung Choul Han Ji Hyeon Kim Sung‐Ho Jin 《Journal of polymer science. Part A, Polymer chemistry》2008,46(3):1083-1097
General, fast, efficient, and inexpensive methods for the synthesis of poly (amido amine) (PAMAM) dendrimers having core diversities were elaborated. In all syntheses, the major step involved an inexpensive 1,3‐dipolar cycloaddition reaction between an alkyne and an azide in the presence of Cu(I) species, which is known as the best example of click chemistry. The propargyl‐functionalized PAMAM dendrons are obtained by the divergent approach using propargylamine as an alkyne‐focal point. Three core building blocks, 1,3,5‐tris(azidomethyl)benzene, N,N,N′,N′‐tetra(azidopropylamidoethyl)‐1,2‐diaminoethane, and 4,4′‐(3,5‐bis(azidopropyloxy)benzyloxy)bisphenyl, were designed and synthesized to serve as the azide functionalities for dendrimer growth via click reactions with the alkyne‐dendrons. These three building blocks were employed together with the propargyl‐functionalized PAMAM dendrons in a convergent strategy to synthesize three kinds of PAMAM dendrimers with different core units. This novel and pivotal strategy using an efficient click methodology provides the fast and efficient synthesis of the PAMAM dendrimers with the tailed made core units. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1083–1097, 2008 相似文献
4.
Hyperbranched poly(amido amine)s containing vinyl and hydroxyl groups were successfully synthesized via Michael addition polymerization of triacrylamide (TT) and 3-amino-1,2-propanediol (APD) with equal molar ratio in feed. 1H, 13C and HSQC NMR techniques were used to clarify the structure of hyperbranched polymers and polymerization mechanism. The Michael addition reaction of hyperbranched poly(1TT-1APD)s with primary amine-terminated poly(ε-benzyloxycarbonyl-l-lysine)s [PLys(Z)] yielded a star-like hyperbranched polymers with poly(1TT-1APD) core and Plys(Z) shell. The Z groups in PLys(Z) were removed under acidolysis, and thus star-like hyperbranched polymers with hydroxyl groups inside and primary amine groups outside were obtained successfully. 相似文献
5.
Ying Lin Zhong‐Ming Dong Xiao‐Hui Liu Yue‐Sheng Li 《Journal of polymer science. Part A, Polymer chemistry》2007,45(18):4309-4321
A new straightforward strategy for synthesis of novel hyperbranched poly (ether amide)s from readily available monomers has been developed. By optimizing the reaction conditions, the AB2‐type monomers were formed dominantly during the initial reaction stage. Without any purification, the AB2 intermediate was subjected to further polymerization in the presence (or absence) of an initiator, to prepare the hyperbranched polymer‐bearing multihydroxyl end‐groups. The influence of monomer, initiator, and solvent on polymerization and the molecular weight (MW) of the resultant polymers was studied thoroughly. The MALDI–TOF MS of the polymers indicated that the polymerization proceeded in the proposed way. Analyses of 1H NMR and 13C NMR spectra revealed the branched structures of the polymers obtained. These polymers exhibit high‐moderate MWs and broad MW distributions determined by gel permeation chromatography (GPC) in combination with triple detectors, including refractive index, light scattering, and viscosity detectors. In addition, the examination of the solution behavior of these polymers showed that the values of intrinsic viscosity [η] and the Mark–Houwink exponent α were remarkably lower compared with their linear analogs, because of their branched nature. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4309–4321, 2007 相似文献
6.
Blencowe A Fagour W Blencowe C Cosstick K Hayes W 《Organic & biomolecular chemistry》2008,6(13):2327-2333
A novel diazirine functionalised aniline derivative, 3-(3-aminophenyl)-3-methyldiazirine 1, was prepared and employed as an AB(2)-type monomer in the synthesis of hyperbranched polymers; thus providing the first instance in which polyamines have been prepared via carbene insertion polymerisation. Photolysis of the monomer 1 in bulk and in solution resulted in the formation of hyperbranched poly(aryl amine)s with degrees of polymerisation (DP) varying from 9 to 26 as determined by gel permeation chromatography (GPC). In solution, an increase in the initial monomer concentration was generally found to result in a decrease in the molecular weight characteristics of the resulting poly(aryl amine)s. Subsequent thermal treatment of the poly(aryl amine)s caused a further increase in the DP values up to a maximum of 31. Nuclear magnetic resonance (NMR) spectroscopic analysis revealed that the increase in molecular weight upon thermal treatment resulted from hydroamination of styrenic species formed in the initial photopolymerisation or activation of diazirine moieties. 相似文献
7.
Qimin Jiang Yongzhuang Du YuanLiang Zhang Liang Zhao Li Jiang Wenyan Huang Hongjun Yang Xiaoqiang Xue Bibiao Jiang 《Journal of polymer science. Part A, Polymer chemistry》2020,58(19):2718-2727
In this research, we developed a novel and facile strategy to prepare aliphatic tertiary amine chromophore hyperbranched poly(amino ether ester)s with pH and thermo responsiveness via phosphazene base (t-BuP2) catalyzed oxa-Michael addition polymerization of triethanolamine with ethylene glycol diacrylate at room temperature. UV–vis and fluorescence analyses results showed that the tertiary amine at branching point for hyperbranched poly(amino ether ester)s is very important to retain strong blue fluorescence of tertiary amine chromophore. Moreover, the hyperbranched poly(amino ether ester)s exhibit an aggregation caused quenching (ACQ) fluorescence, solvent induced red-shifted emission, molecular weight, and temperature dependent emission characters. More interestingly, the hyperbranched poly(amino ether ester)s show extreme acid induced quenching fluorescence phenomenon, and also display good water solubility, specific recognition of Fe3+ ion, low cytotoxicity, and bright cell imaging, which could serve as a microenvironment-responding fluorescent probe for application in chemical sensing, cell imaging, drug delivery, or disease diagnostics. This research provides a versatile method for the preparation of stimuli-responsive aliphatic tertiary amine chromophore polymers, and supplies ideas for researchers to explore other unconventional fluorescent polymers for application. 相似文献
8.
《Journal of polymer science. Part A, Polymer chemistry》2018,56(16):1853-1859
The para‐fluoro‐thiol “click” reaction (PFTCR) was utilized to prepare linear and hyperbranched fluorinated poly (aryl ether‐thioether). For this purpose, 1,2‐bis(perfluorophenoxy)ethane was prepared and reacted with 1,6‐hexandithiol and trimethylolpropane tris(3‐mercaptopropionate), respectively. While hyperbranched polymers were prepared using 0.5 M concentrations of starting materials at room temperature, the linear polymer syntheses were performed at different reaction temperatures and concentrations. The resulting polymers were mainly characterized by NMR measurements and a very distinct fluorine signals regarding meta‐ and ortho‐ positions in the 19F NMR were found for both polymer topologies. In addition to NMR analyses, both linear and hyperbranched polymers were further characterized by using Fourier transform infrared spectroscopy (FT‐IR), gel permeation chromatography (GPC), and differential scanning calorimetry (DSC). © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 1853–1859 相似文献
9.
We report a facile synthesis method of dendrimer-like star-branched poly(N-isopropylacrylamide) (PNIPAM) via the combination of click chemistry and atom transfer radical polymerization (ATRP) by employing the arm-first approach. First, the α-azido-ω-chloro-heterodifunctionalized building block, N 3-PNIPAM-Cl (G0-Cl), was synthesized via ATRP by 3-azidopropyl 2-chloropropionate as the initiator. Taking advantage of click chemistry, the first generation (G1) of dendrimer-like star-branched PNIPAM, G1-(Cl)3, was facilely prepared via the click coupling reaction between G0-Cl and tripropargylamine. For the construction of second generation (G2) dendrimer-like star-branched PNIPAM, G2-(Cl)6, terminal chloride moieties of G1-(Cl)3 were first converted to azide, and then reacted with excess tripropargylamine to give G1-(alkynyl)6; G2-(Cl)6 was subsequently prepared via click reaction between G1-(alkynyl)6 and G0-Cl. Gel permeation chromatography (GPC) and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry were employed to confirm the successful construction of dendrimer-like star-branched polymers. The unique thermal phase transition behavior of this dendrimer-like star-branched polymer in aqueous solutions was further investigated by turbidimetry and micro-differential scanning calorimetry (Micro-DSC). 相似文献
10.
A green, operationally simple and highly efficient one-pot three-component approach for the synthesis of spiro[indoline-3,4′-thiopyrano[2,3-b]indole] derivatives has been developed by the domino reaction of indoline-2-thione, isatin and ethyl cyanoacetate or malononitrile in ethanol at 80 °C for just 20 min. The significant advantages of this protocol are short reaction time, excellent yields, operational simplicity and formation of three new bonds in one operation from easily available starting materials. 相似文献
11.
Joel R. Morgan Mary J. Cloninger 《Journal of polymer science. Part A, Polymer chemistry》2005,43(14):3059-3066
Mannose‐functionalized and ethoxyethanol‐functionalized poly(amido)amine dendrimers bound multiple vanadate‐substituted polyoxotungstate Wells–Dawson‐type polyoxometalates (POMs). Dendrimers incorporating 10–30 POMs were characterized with NMR, transmission electron microscopy, and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry techniques. The number of metal clusters per dendrimer molecule varied according to the dendrimer generation and the nature of the surface functional groups. Efforts aimed at using the poly(polyoxometalate) dendrimers as oxidation catalysts are also described. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3059–3066, 2005 相似文献
12.
LI HongKun MEI Ju WANG Jian ZHANG Shuang ZHAO QiuLi WEI Qiang QIN AnJun SUN JingZhi & TANG Ben Zhong MOE Key Laboratory of Macromolecular Synthesis Functionalization 《中国科学B辑(英文版)》2011,(4)
Regioseletive 1,3-dipolar polycycloadditions of 4,4'-isopropylidenediphenyl dipropiolate (1) and tetraphenylethene (TPE)-containing diazides (2) are carried out in polar solvents such as DMF/toluene at a moderate temperature of 100℃ for 6 h,producing poly(aroxycarbonyltriazole)s (PACTs) P3 with high molecular weights (Mw up to 23900) and regioregularities (F1,4 up to ~90%) in high yields (up to ~99%).These metal-free click polymerizations can propagate smoothly in an open atmosphere without protection from ... 相似文献
13.
A novel convergent route to 3-arm star polymers is described that takes advantage of RAFT-synthesized homopolymers serving as masked macromolecular terminal thiol-containing materials capable of undergoing thiol-ene click reactions. 相似文献
14.
Tomohiro Kubo Morgan S. Young Kendra D. Souther Matthew D. Hannigan Anne J. McNeil 《Journal of polymer science. Part A, Polymer chemistry》2021,59(3):268-273
The discovery of catalyst-transfer polymerization and its further developments have led to unprecedented control over the length and sequence of conjugated polymers. However, the methods themselves are technically challenging to perform due to the air- and moisture-sensitivities of the monomers and catalysts. Herein, we report a catalyst-transfer polymerization method that affords poly(3-hexylthiophene) in high yields without using an inert atmosphere. The synthesis capitalizes on a rapid Negishi cross-coupling using a moisture-tolerant organozinc monomer mediated by an air-stable Pd precatalyst. This simple method should make conjugated polymer synthesis more accessible to a broader range of researchers and may be generalizable to other monomer scaffolds. 相似文献
15.
Xiaofeng Zhang Shen Lin Xinqing Chen Jiebo Chen Liuyi Yang Minghong Luo 《Frontiers of Chemistry in China》2007,2(4):419-421
Mesoporous aluminophosphate was prepared by using G4.0 poly(amido amine)dendrimer as a template and characterized by Fourier
transform infrared spectrometer (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and N2 adsorption/desorption methods. Results show that the title compound exhibits a typical mesoporous structure with the average
pore size from 5 to 8 nm. The formation mechanism of the nanoporous structure using dendrimer as a template was also discussed.
__________
Translated from Journal of Fujian Normal University (Natural Science Edition), 2007, 23(2): 67–70 [译自: 福建师范大学学报 (自然科学版)] 相似文献
16.
The present study describes a method of incorporating amine functional groups on poly(dimethylsiloxane) chains as pendant groups on silicon atoms. This method allows for independent control of the molecular weight and the amine content of the oligomer. The new molecular design was achieved by co-equilibration of the cyclic tetramer octamethylcyclotetrasiloxane (D4) with a new cyclic siloxane monomer containing aliphatic amine substituents on the silicon atoms. The co-equilibration of the two cyclic siloxanes was carried out in the presence of a silanolate catalyst, using the nonfunctionalized hexamethyldisiloxane as the end-capper. The distribution of the molecular species at thermodynamic equilibrium and the efficiency of incorporation of siloxane units containing pendant amine functionalities into the poly(dimethylsiloxane) chains were investigated as a function of oligomer chemical composition and molecular weight. 相似文献
17.
Ribovski Laís dos Santos Fabrício A. Zucolotto Valtencir Janegitz Bruno C. 《Journal of Solid State Electrochemistry》2019,23(5):1581-1591
Journal of Solid State Electrochemistry - The use of gold nanomaterials in electrochemical biosensing has been proven to be effective either by modifying the electrodes’ surface or by... 相似文献
18.
Mingxiu Lv Mengwei Wang Kui Lu Lu Peng Yufen Zhao 《Phosphorus, sulfur, and silicon and the related elements》2018,193(3):149-154
A facile, rapid and cheap synthetic strategy towards a wide range of novel 2-aminoethylidene-1,1-bisphosphonate derivatives was developed through the Michael addition reaction of various aromatic amines, aromatic amides as well as nucleoside analogues with tetraethyl ethenylidene-1,1-bisphosphonate. All the newly obtained compounds were characterized by 1H, 31P, 13C NMR spectroscopy, IR and HR MS. 相似文献
19.
Jialing Xian Lin Chen Ling Ye Yin Sun Zhichuan Shi Zhigang Zhao Xuefeng Li 《Tetrahedron》2019,75(15):2350-2356
A highly enantioselective (49–99% ee) Michael addition/lactonization cascade process has been developed to construct 3,4-dihydropyran-2-one in the presence of a bifunctional squaramide. Various α,β-unsaturated N-acyl heterocycles were well tolerated and afforded 3,4-dihydropyran-2-ones in moderate to excellent isolated yields (50–99%). Both cyclic and acyclic β-diketones functioned as appropriate donors. The resulting 3,4-dihydropyran-2-ones could be readily converted into oxadecalinones. 相似文献
20.
Li‐Zhi Kong Miao Sun Hua‐Ming Qiao Cai‐Yuan Pan 《Journal of polymer science. Part A, Polymer chemistry》2010,48(2):454-462
Well‐defined hyperbranched polystyrenes have been successfully prepared by polymerization of AB2 macromonomer, polystyrene containing an azide group at its one end and two terminal propargyl groups at the other end via click reaction. For preparation of AB2 macromonomers, an ATRP initiator, bispropargyl 2‐bromosuccinate (BPBS) with two propargyl groups and one bromine group was synthesized by the successive bromination and esterification reaction of L ‐aspartic acid. The resulting BPBS initiated the ATRP of St, and subsequently, the terminal bromine groups of (CH≡C)2‐PS‐Brs were substituted by N3 via the reaction with sodium azide resulting the AB2 macromonomer, (CH≡C)2‐PS‐N3 with various molecular weights. All intermediates and the resultant polymers were characterized by GPC, 1H NMR, FTIR, and MALLS methods. The polymerization kinetics study showed fast increase of DP at the initial stage of polymerization and then slow increase of their DP. The final “HyperMacs” have high‐molecular weight up to Mw,MALLS = 340,000 g/mol, their molecular weight distributions were moderately narrow (Mw/Mn = 1.47–1.65). The ratios of [η]H/[η]L of the HyperMacs formed in the polymerization system increased with evolution of polymerization. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 454–462, 2010 相似文献