scholarly journals Copolymers based on N-acryloyl-L-leucine and urea methacrylate with pyridine moieties

2016 ◽  
Vol 81 (3) ◽  
pp. 307-322 ◽  
Author(s):  
Emil Buruiana ◽  
Mioara Murariu
Keyword(s):  
Experimental Data ◽  
Gel Permeation Chromatography ◽  
Specific Rotation ◽  
Optically Active ◽  
Molar Ratio ◽  
Carboxyl Group ◽  
Thermal Methods ◽  
Vis Spectroscopy ◽  
Gel Permeation ◽  
Copolymer Poly

By using free radical polymerization of (N-methacryloyloxyethyl-N?-4-picolyl)-urea (MAcPU) and N-acryloyl-L-leucine (AcLeu), an optically active copolymer, poly[(N-methacryloyloxyethyl-N?-4-picolyl)-urea-co-N-acryloyl-L-leucine], MAcPU-co-AcLeu (1.86:1 molar ratio) was prepared and subsequently functionalized at the pyridine-N with (1R/S)-(?/+)-10-camphorsulfonic acid (R/S-CSA) and at carboxyl group with (R)-(+)-?-ethylbenzylamine (R-EBA) or trans-4-stilbene methanol (t-StM). The structures, chemical composition and chiroptical activity of the monomers and the copolymers were characterized by spectral analysis (FTIR, 1H (13C)-NMR, 1H,1H-COSY, UV/vis), thermal methods (TGA, DSC), fluorescence spectroscopy, gel permeation chromatography and specific rotation measurements. Influence of the optical activity of monomer and modifier on modified copolymers suggested a good correlation between the experimental data obtained (23[?]589=+12.5? for AcLeu and MAcPU-co-AcLeu, 23[?]589=0?+27.5? for (MAcPU-co-AcLeu)-R/S-CSA, 23[?]589=+25? for (MAcPU-co-AcLeu)-R-EBA, and 23[?]589 = 0? for (MAcPU-co-AcLeu)-St). In addition, the photobehavior of the stilbene copolymer (MAcPU-co-AcLeu)-St in film was investigated by UV-vis spectroscopy. The fluorescence quenching of the stilbene species in the presence of aliphatic/aromatic amine in DMF solution was evaluated, more efficiently being 4,4??dipyridyl (detection limit: 7.2 x 10-6 mol/L).

scholarly journals Photonic crystals obtained by soap-free emulsion terpolymerization

2014 ◽  
Vol 12 (1) ◽  
pp. 126-130
Author(s):  
Edina Rusen ◽  
Aurel Diacon ◽  
Alexandra Mocanu
Keyword(s):  
Homogeneous Nucleation ◽  
Water Solubility ◽  
Gel Permeation Chromatography ◽  
Nucleation Mechanism ◽  
Hydroxyethyl Methacrylate ◽  
System A ◽  
Vis Spectroscopy ◽  
Gel Permeation ◽  
Nucleation Mechanisms ◽  
Generating System

AbstractThis paper presents the use of soap-free emulsion terpolymerization to obtainphotonic crystals (PCs). Monodisperse latexes resulted from the polymerization of styrene (ST) with 2-hydroxyethyl methacrylate (HEMA) and acrylic acid (AA) at different compositions defined as system A, B and C respectively. The water solubility of the macroradicals determined different nucleation mechanisms in all three cases. The micellar nucleation mechanism was more predominant for generating system A, whereas the homogeneous nucleation was specific for system C. For system B, both nucleation mechanisms werepossible with the same probability. The latexes and the resulted PCs were characterized by optical microscopy (OM), dynamic light scattering (DLS), gel permeation chromatography (GPC) and UV-VIS spectroscopy.

A convenient route to distannanes, oligostannanes, and polystannanes

2010 ◽  
Vol 88 (10) ◽  
pp. 1046-1052 ◽  
Author(s):  
Aman Khan ◽  
Robert A. Gossage ◽  
Daniel A. Foucher
Keyword(s):  
Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Low Pressure ◽  
Inert Atmosphere ◽  
Major Product ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Gel Permeation ◽  
Highly Dispersed ◽  
Convenient Route

The quantitative conversion of the tertiary stannane (n-Bu)3SnH (2) into (n-Bu)6Sn2 (4) was achieved by heating the neat hydride material under low pressure or under closed inert atmosphere conditions. A 31% conversion of Ph3SnH (3) to Ph6Sn2 (5) was also observed under low pressure; however, under closed inert atmosphere conditions afforded Ph4Sn (6) as the major product. A mixed distannane, (n-Bu)3SnSnPh3 (7), can also be prepared in good yield utilizing an equal molar ratio of 2 and 3 and the same reaction conditions used to prepare 4. This solvent-free, catalyst-free route to distannanes was extended to a secondary stannane, (n-Bu)2SnH2 (8), which yielded evidence (NMR) for hydride terminated distannane H(n-Bu)2SnSn(n-Bu)2H (9), the polystannane [(n-Bu)2Sn]n (10), and various cyclic stannanes [(n-Bu)2Sn]n=5,6 (11, 12). Further evidence for 10 was afforded by gel permeation chromatography (GPC) where a broad, moderate molecular weight, but highly dispersed polymer, was obtained (Mw = 1.8 × 104 Da, polydispersity index (PDI) = 6.9) and a characteristic UV–vis absorbance (λmax) of ≈370 nm observed.

scholarly journals One-Pot Preparation of Metal–Polymer Nanocomposites in Irradiated Aqueous Solutions of 1-Vinyl-1,2,4-triazole and Silver Ions

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4235
Author(s):  
Alexey A. Zezin ◽  
Alexey A. Zharikov ◽  
Artem I. Emel’yanov ◽  
Alexander S. Pozdnyakov ◽  
Galina F. Prozorova ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Monomer Concentration ◽  
Gel Permeation Chromatography ◽  
Silver Ions ◽  
Polymer Nanocomposite ◽  
Molar Ratio ◽  
One Pot ◽  
Radiation Chemical ◽  
Vis Spectroscopy ◽  
Metal Polymer

Metal–polymer nanocomposite polyvinyltriazole–silver nanoparticles were obtained using one-pot synthesis in irradiated aqueous solutions of 1-vinyl-1,2,4-triazole (VT) and silver ions. Gel permeation chromatography data show that upon radiation initiation, the molecular weight of poly(1-vinyl-1,2,4-triazole) increases with increasing monomer concentration. To study the kinetics of polymerization and the features of the radiation–chemical formation of nanoparticles, UV-Vis spectroscopy was used. TEM images show a relatively small average size of the forming nanoparticles (2–3 nm) and a narrow size distribution, which shows the effective stabilization of nanoparticles by triazole substituents at a molar ratio of VT and silver ions of 25/1. The addition of ethyl alcohol was used to increase the efficiency of synthesis and suppress the crosslinking of macromolecules in solution. The results of the work show that aqueous–alcoholic solutions of 1 wt.% VT can be used to obtain soluble nanocomposite materials. 10 wt.% monomer solutions have prospects for use in the preparation of polymer gels filled with nanoparticles.

Novel Amphiphilic Star-Shaped Poly(2-Oxazoline)s with Calix[4]Arene Branching Center

2021 ◽  
Vol 899 ◽  
pp. 300-308
Author(s):  
Aleksei N. Blokhin ◽  
Alla B. Razina ◽  
Andrey V. Tenkovtsev
Keyword(s):  
Aqueous Solutions ◽  
Ring Opening ◽  
Gel Permeation Chromatography ◽  
Ring Opening Polymerization ◽  
Arene Derivative ◽  
Vis Spectroscopy ◽  
Gel Permeation ◽  
Grafting From ◽  
Cationic Ring Opening Polymerization

Novel amphiphlic four-arm star-shaped poly (2-alkyl-2-oxazoline) s with calix [4] arene core were synthesized using the “grafting from” approach. The chlorosulfonated calix [4] arene derivative was synthesized and successfully applied as a multifunctional initiator for the cationic ring-opening polymerization of 2-alkyl-2-oxazolines. Obtained star-shaped poly (2-alkyl-2-oxazoline) s were characterized by means of NMR, UV-Vis spectroscopy and gel-permeation chromatography. It was shown that star-shaped poly (2-isopropyl-2-oxazoline) perform thermosensitivity in aqueous solutions.

Study on Synthesis and Properties of Phenols Polymer Syntan Catalyzed by Enzyme

2011 ◽  
Vol 138-139 ◽  
pp. 1072-1077
Author(s):  
Sheng Hua Lv ◽  
Rui Gong ◽  
Yan Fen Ma
Keyword(s):  
Molecular Weight ◽  
Nuclear Magnetic Resonance ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Molar Ratio ◽  
Structure And Properties ◽  
Monomer Composition ◽  
Gel Permeation

A phenolic copolymer was synthesized from resorcinol (RSC) and 3,5-dihydroxy benzoic acid (DBA) using horseradish peroxidase (HRP)/H2O2 as the radical copolymerization’s initiateor. It was discussed that the effects of monomer composition on the properties of the copolymer. The best molar ratio was 1:1. The structure and properties of the copolymer was characterized by Fourier Transform Infrared spectroscopy (FTIR) and Nuclear Magnetic Resonance (HNMR), Molecular weight (MW) was determined by gel permeation chromatography (GPC). The result shows that the average molecular weight of the copolymer is about 40000. The effect of dosage of HRP on the properties of the copolymer was investigated. And the mechanism of polymerization of RSC and DBA was advanced. The copolymer was used as tanning agent, applied results show that it has excellent retanning properties. It was realized the applicatiom of HRP on the phenols syntan.

scholarly journals Supramolecular poly(L-lactide)s containing terpyridine metal complexes

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Marcel Heller ◽  
Ulrich S. Schubert
Keyword(s):  
Mass Spectrometry ◽  
Metal Complexes ◽  
Phase Transfer ◽  
Gel Permeation Chromatography ◽  
Diode Array ◽  
Maldi Tof Mass Spectrometry ◽  
Full Characterization ◽  
Maldi Tof ◽  
Vis Spectroscopy ◽  
Gel Permeation

AbstractChiral poly(L-lactide)s end-capped with a novel terpyridine ligand are synthesized by a controlled coordinative polymerization procedure. The resulting well-characterized macroligands can be complexed under phase-transfer conditions with iron(II) ions to form well-defined supramolecular poly(L-lactide) complexes. The outstanding stability of such coordinative polymers enables the full characterization by gel permeation chromatography (GPC) and MALDI-TOF mass spectrometry. In addition, in-line diode array UV-Vis spectroscopy coupled to GPC was carried out to verify the formation of the poly(ester) complexes.

Synthesis and characterisation of organotin(IV) derivatives of ambidentate ligands containing nitrogen and sulphur donor atoms

2011 ◽  
Vol 34 (5-6) ◽  
pp. 131-137 ◽  
Author(s):  
Rafael César Russo Chagas ◽  
José Roberto da Silveira Maia ◽  
Vany P. Ferraz
Keyword(s):  
Room Temperature ◽  
Bond Angle ◽  
Gel Permeation Chromatography ◽  
Molar Ratio ◽  
Trigonal Bipyramidal ◽  
Distorted Octahedral ◽  
Gel Permeation ◽  
Derivatives Of ◽  
Octahedral Configuration ◽  
Distorted Trigonal Bipyramidal

Abstract A series of organotin(IV) derivatives of bis(pyrimidin-2-ylthio)methane (ptm), 1,2-bis(pyrimidin-2-ylthio)ethane (pte) and 1,6-bis(pyrimidin-2-ylthio)hexane (pth) have been prepared in dichloromethane at room temperature. The 2:1 (M/L) molar ratio compounds have a general formula of [Sn2ClxPh8-xL] (x=2, 4, 6, 8; L=ptm, pte and pth). A 1:1 complex was also obtained by reacting SnClPh3 with pth. The organotin derivatives were characterised by multinuclear NMR (1H, 13C and 119Sn) and infrared spectroscopy, gel permeation chromatography (GPC), microanalysis and melting point. In the triphenyltin derivatives, 1, 5, 9 and 10 the tin atoms show a distorted trigonal-bipyramidal configuration where the ligand is monodentate towards the metal atom. In the compounds 2–4, 6–8 and 11–13, the tin atoms each exhibit a distorted octahedral configuration. Chelation is formed between the tin nucleus and the coordinating sulphur and nitrogen atoms. The correlation between the 1J(13C-119Sn) and C-Sn-C bond angle indicates formation of 5-coordinate compounds.

scholarly journals Dispersing Effect of Core Cross-linked Star Polycarboxylate Superplasticizers on the Cement Paste

2021 ◽  
Vol 283 ◽  
pp. 01048
Author(s):  
Jinlong Zhang ◽  
Furen Huang ◽  
Xiaolong Chen ◽  
Kaihong Zhong ◽  
Haijun Xu
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Cement Paste ◽  
Conversion Efficiency ◽  
Gel Permeation Chromatography ◽  
Molar Ratio ◽  
Hydrophobic Core ◽  
Reducing Ability ◽  
Gel Permeation ◽  
Dispersing Ability

Researches on topological modification of polycarboxylate superplasticizers to improve the water-reducing or slump-retainning properties have been a hot topic in rencent years. Herein, a core crosslinked star polycarboxylate superplasticizers (SPCE) were synthesized by crosslinking the comb polycarboxylate superplasticizers (CPCE) in aqueous solution. Crosslinkers and spacing monomers were added into the polymerization to promote the formation of hydrophobic core. A larger molecular weight with 75% of yields of the SPCE were observed by gel permeation chromatography (GPC). The dispersing effect of SPCE on the cement paste was then investigated by varying the dosage of crosslinkers and spacing monomers. It was found that the dispersing ability of SPCE became weakened compared to the CPCE. More of the crosslinkers led to smaller flow spread, as revealed by cement paste experiments. Introduction of the spacing monomers contributed to the formation of SPCE. However, the dispersing ability was also weakened. Best conversion efficiency and water-reducing ability was obtained when the molar ratio of crosslinker and spacing monomer to CPCE was set as 3:5:1.

The Synthesis of Binuclear Mono-Cyclopentadinyl Titanocene and its Using for Aqueous Homo-Polymerization of Methyl Methacrylate

2010 ◽  
Vol 44-47 ◽  
pp. 3036-3040
Author(s):  
Yu Jing Nie ◽  
Zheng Zai Cheng ◽  
Rui Lei ◽  
Xiao Chao Yan ◽  
Su Su Lin
Keyword(s):  
Nmr Spectroscopy ◽  
Methyl Methacrylate ◽  
1H Nmr Spectroscopy ◽  
Gel Permeation Chromatography ◽  
Molar Ratio ◽  
Reaction Parameters ◽  
Titanium Complex ◽  
Gel Permeation ◽  
Temperature Time ◽  
Water Amount

One binuclear mono-cyclopentadinyl titanocene, CpTiCl3(CH2)4CpTiCl3, has been synthesized by a new ways and characterized by 1H-NMR spectroscopy and elemental analysis. Its aqueous medium polymerization properties of methyl methacrylate (MMA) have been pursued with an anionic surfactant, sodiumn dodecylsulfate(SDS) in water. The obtained polymers were characterized by gel permeation chromatography(GPC). GPC results showed that the dinuclear titanium complex might provide PMMA with broad PDI(PDI=10.82). Influences of reaction parameters, such as temperature, time, MMA/Cat(molar ratio) and water amount were studied in detail. Under the conditions of the temperature was 55 °C, the reaction lasted l5h, the molar ratio of Cat to MMA was l:200, and the volume of water consumed was 40 ml, the conversion of MMA was as high as 70%.

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