Preparation and characterization of some new diaminobisimides

1994 ◽  
Vol 6 (4) ◽  
pp. 287-301 ◽  
Author(s):  
D G Hawthorne ◽  
J H Hodgkin ◽  
M B Jackson ◽  
J W Loder ◽  
T C Morton
Keyword(s):  
Gel Permeation Chromatography ◽  
Aromatic Diamine ◽  
Side Reactions ◽  
Amino Groups ◽  
Aromatic Diamines ◽  
Reaction Conditions ◽  
Condensation Polymers ◽  
Yield And Purity ◽  
C Nmr

A series of stable diaminobisimides (DABIs) has been prepared as alternatives to simple aromatic diamines for use in the preparation of condensation polymers. These DABIs were prepared by reacting two moles of an aromatic diamine with one mole of a dianhydride under conditions that minimize side reactions and the formation of oligomers. In many cases, the pure DABI consisting of two moles of the diamine and one mole of the dianhydride (i.e. the 2:1 product) can be obtained free of oligomers (i.e. the 3:2, 4:3 etc products). The studies have shown that the major factor determining the yield and purity of a DABI is the extent of conjugation between the two amino groups in the starting diamine: to a lesser extent steric effects in the diamines also influence the product composition. The reaction conditions necessary to produce these new DABIs are described together with extensive characterization of these materials by FTIR,1H and 13C NMR and gel permeation chromatography. The results indicate that pure DABIs are more manageable materials than the impure. insoluble materials previously described in the literature and can be used successfully to produce useful high-temperature stable polymers.

Surface Grafting Modification of Silk Fibroin by Atom Transfer Radical Polymerization

2008 ◽  
Vol 373-374 ◽  
pp. 629-632 ◽  
Author(s):  
Tie Ling Xing ◽  
Hai Jiang Wang ◽  
Zhan Xiong Li ◽  
Guo Qiang Chen
Keyword(s):  
Silk Fibroin ◽  
Gel Permeation Chromatography ◽  
Catalyst System ◽  
Hydroxyl Groups ◽  
Amino Groups ◽  
Grafting Modification ◽  
Antibacterial Surface ◽  
Ft Ir ◽  
Tertiary Amino

In this work, surface modification of silk fibroin was conducted by grafting dimethylaminoethyl methacrylate (DMAEMA) via ATRP to produce well controlled grafting silk. First, the amino groups and hydroxyl groups on the side chains of the silk fibroin reacted with 2-bromoisobutyryl bromide (BriB-Br) to obtain efficient initiator for ATRP. Subsequently, the functional silk fibroin was used as macroinitiator of DMAEMA in 1,2-dichlorobenzene in conjunction with CuBr/N,N,N',N",N" -pentamethyldiethylenetriamine (PMDETA) as a catalyst system. FT-IR characterization of the modified silk substrate showed a peak corresponding to DMAEMA indicating that the polymer had been formed on the silk surface. Following the polymerization, the tertiary amino groups on the grafted silk fibroin were quaternized to produce a large concentration of quaternary ammonium groups, which endowed the silk substrate with potential antibacterial surface. The graft chains were cleaved by acid hydrolysis and analyzed by gel permeation chromatography (GPC). The GPC results indicated that the graft layer were well-controlled.

scholarly journals Synthesis of poly(γ-tert-butyl L-glutamate): influence of polymerization conditions

2019 ◽  
Vol 16 (3) ◽  
pp. 25
Author(s):  
Phung Thi Thuy Dung ◽  
Nguyen Thi Le Thu
Keyword(s):  
Ring Opening ◽  
Gel Permeation Chromatography ◽  
Attenuated Total Reflection ◽  
Resonance Spectroscopy ◽  
Reaction Conditions ◽  
Tert Butyl ◽  
Ft Ir ◽  
Hydrolysis Of ◽  
Polymerization Conditions

This work presents the synthesis and characterization of poly(γ-tert-butyl L-glutamate) (PtBuLG) via a living ring-opening polymerization procedure of γ-tert-butyl L-glutamate N-carboxyanhydride (tBuLG-NCA). The reaction conditions were investigated to optimize the polymerization yield and molecular weight polydispersity. The synthesized PtBuLG was characterized using nuclear magnetic resonance spectroscopy (NMR), gel permeation chromatography (GPC) and attenuated total reflection-Fourier transform infrared (ATR FT-IR. Finally, hydrolysis of PtBuLG resulted in poly(L-glutamic acid) (PLGA).

Characterization of aspen exploded wood lignin

1982 ◽  
Vol 60 (18) ◽  
pp. 2372-2382 ◽  
Author(s):  
R. H. Marchessault ◽  
Suzanne Coulombe ◽  
Hiromichi Morikawa ◽  
Danielle Robert
Keyword(s):  
Room Temperature ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Aryl Ether ◽  
Weight Average Molecular Weight ◽  
Nmr Spectrum ◽  
Typical Composition ◽  
Moist Steam ◽  
C Nmr

Exploded wood lignin (EXWL) was extracted from moist steam hydrolysed aspen (Populustremuloides) wood using methanol. The lignin was examined by elemental analysis, gel permeation chromatography, infrared spectroscopy, proton and 13C nmr. The observed nmr spectra were compared with those of aspen milled wood lignin (MWL). Typical composition of the material is C9H9.2O2.7(OCH3)1.1 Assignment of all the signals in the nmr spectrum led to the conclusion that the explosion process causes cleavage of the β-aryl-ether bond. The weight average molecular weight was found to be 1700–1900 and the polydispersity 2.6. The finely divided exploded wood was soluble in 90% methanol/water mixtures to well beyond 20% by weight at room temperature.

scholarly journals Synthesis and Characterization of Syndiotactic Polystyrene-Polyethylene Block Copolymer

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 698 ◽  
Author(s):  
Lamparelli ◽  
Speranza ◽  
Camurati ◽  
Buonerba ◽  
Oliva
Keyword(s):  
Direct Synthesis ◽  
Gel Permeation Chromatography ◽  
Syndiotactic Polystyrene ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Reaction Conditions ◽  
Force Microscopy ◽  
Synthetic Strategy ◽  
Atomic Force

The direct synthesis of syndiotactic polystyrene-block-polyethylene copolymer (sPS-b-PE) with a diblock structure has been achieved. The synthetic strategy consists of the sequential stereocontrolled polymerization of styrene and ethylene in the presence of a single catalytic system: cyclopentadienyltitanium(IV) trichloride activated by modified methylaluminoxane (CpTiCl3/MMAO). The reaction conditions suitable for affording the partially living polymerization of these monomers were identified, and the resulting copolymer, purified from contaminant homopolymers, was fully characterized. Gel permeation chromatography coupled with two-dimensional NMR spectroscopy COSY, HSQC, and DOSY confirmed the block nature of the obtained polymer, whose thermal behaviour and thin film morphology were also investigated by differential scanning calorimetry, powder wide angle x-ray diffraction, and atomic force microscopy.

Synthesis and characterization of 4-chloromethylstyrene polymers containing bulky organosilicon groups

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Kazem Dindar Safa ◽  
Mirzaagha Babazadeh
Keyword(s):  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Gel Permeation Chromatography ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
H Nmr ◽  
Gel Permeation ◽  
Covalently Linked ◽  
C Nmr

Abstract The homopolymer of 4-chloromethylstyrene and its copolymers with styrene (in 1:3 and 1:1 mole ratio) were synthesized by bulk and solution freeradical polymerisations, respectively, at 70±1°C using α,α'-azoisobutyronitrile as an initiator. Highly sterically hindered tris(trimethylsilyl)methyl (Tsi) substituents were then covalently linked to the obtained homopolymer and copolymers. The polymers were characterized by IR, 1H NMR and 13C NMR, differential scanning calorimetry (DSC) and gel permeation chromatography. DSC showed that incorporation of Tsi substituents in the side chains of homopolymer and copolymers increases the rigidity of the polymers and, subsequently, their glass transition temperature.

Synthesis and Characterization of Soluble, High Temperature 3-Phenylethynyl Aniline Functionalized Polyimides via the Ester-Acid Route

1993 ◽  
Vol 305 ◽  
Author(s):  
G. W. Meyer ◽  
S. Jayaraman ◽  
Y. J. Lee ◽  
G. D. Lyle ◽  
T. E. Glass ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Curing Temperature ◽  
Flow Properties ◽  
Aromatic Diamines ◽  
One Pot ◽  
Excellent Thermal Stability ◽  
Processing Window ◽  
The One

AbstractThe synthesis of soluble imide oligomers of controlled molecular weight endcapped with the 3-phenylethynyl aniline endcapping agent is described. The 3-phenylethynyl aniline was employed to afford a higher curing temperature (380 - 420°C) which widens the processing window compared to commercially available acetylene endcapped polyimides. The polyimides were synthesized via solution imidization techniques, using the ester-acid of various dianhydrides and various aromatic diamines. The “one pot” procedure utilizes NMP as the solvent and o-dichlorobenzene as the azeotroping agent, and reproducibly exhibit fully imidized soluble polyimides with Mw/Mn values of ∼2.0 determined by gel permeation chromatography. Thermally cured samples display good solvent resistance and exhibit glass transition temperatures comparable to their high molecular weight linear analogs. These polyimides show excellent thermal stability at 700°F aged in air up to 100 hours. Mechanical testing has been performed on a pyromellitic dianhydride (PMDA) and a phosphine oxide-based system. The flow properties have been studied by parallel plate rheology and the cure cycle has been monitored using 13CNMR.

scholarly journals Syntheses and solution properties of water-soluble poly(p-phenylene)s bearing oligo(ethylene oxide) and trialkylamino side groups

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Steffen Traser ◽  
Patrick Wittmeyer ◽  
Matthias Rehahn
Keyword(s):  
Ethylene Oxide ◽  
Aqueous Media ◽  
Amino Nitrogen ◽  
Water Soluble ◽  
Side Chains ◽  
Amino Groups ◽  
Reaction Conditions ◽  
Substitution Pattern ◽  
Polycondensation Process ◽  
C Nmr

AbstractPd-catalyzed Suzuki coupling is used to prepare poly(p-phenylene)s (PPPs) bearing oligo(ethylene oxide)s (OEOs) and trialkylamino groups as lateral substituents. The OEO substituents require very specific reaction conditions during monomer synthesis - presumably due to their coordinating oxygen atoms - but do not affect the subsequent Pd-catalyzed polycondensation process. In contrast to this, the lateral amino groups lower the degree of polycondensation of the PPPs considerably when their nitrogen atom is placed in the β-position of the side chains. When there is a longer spacer group between the amino nitrogen and the aromatic ring to be coupled, however, high-molecular-weight PPPs can be obtained. Provided an appropriate substitution pattern and long OEO side chains are used, the resulting PPPs are readily soluble not only in organic solvents but even in aqueous media. For one of these PPPs, the degree of protonation has been determined as a function of pH, using 1H and 13C NMR spectroscopy as well as potentiometry. It is shown that the polymer is completely deprotonated at pH > 10.5 and quantitatively protonated at pH < 4.0.

scholarly journals Synthesis and Characterization of 1-(1-chlorocyclopropyl)-2-(1,2,4-triazol-1-yl)ethan-1-one

2017 ◽  
Vol 19 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Haifeng Ji ◽  
Yabin Niu ◽  
Dongming Liu ◽  
Weidong Wang ◽  
Chuanbo Dai
Keyword(s):  
Magnetic Resonance ◽  
Phase Transfer ◽  
Operating Conditions ◽  
High Yield ◽  
Temperature Ratio ◽  
Reaction Conditions ◽  
Synthetic Process ◽  
H Nmr ◽  
C Nmr

Abstract A simple and efficient method to prepare 1-(1-chlorocyclopropyl)-2-(1,2,4-triazol-1-yl)ethan-1-one via nucleophilic substitution of 2-chloro-1-(1-chlorocyclopropyl)ethanone and 1,2,4-triazole is described. The title compound is the key intermediate required for the synthesis of prothioconazole, a promising agricultural fungicide. By exploring changes in the reaction time, temperature, ratio of starting reagents, acid binding agent, and the nature of phase transfer catalyst, the reaction conditions could be optimized to afford the desired N-alkylated material in near-quantitative yield. The ultimate yield of the product after recrystallization was 93%, with a purity of 99% based on its characterization by Gas Chromatography-Mass Spectrometer (GC-MS), Fourier Transform infrared spectroscopy (IR), Proton Magnetic Resonance (1H NMR), and Carbon-13 Nuclear Magnetic Resonance (13C NMR). The synthetic process is suitable for industrial application, with the advantages of high yield and facile preparation under mild operating conditions.

scholarly journals Synthesis and Characterization of Acrylamide-Based Anionic Copolymer and Investigation of Solution Properties

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
H. Jamshidi ◽  
A. Rabiee
Keyword(s):  
Molecular Weight ◽  
Nmr Spectroscopy ◽  
Solution Viscosity ◽  
Feed Ratio ◽  
Reaction Conditions ◽  
Aqueous Sodium Chloride Solution ◽  
Shear Rates ◽  
High Molecular Weight Product ◽  
C Nmr

The copolymer of acrylamide (AM) and 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS) was synthesized through radical solution polymerization by potassium persulfate as initiator. By changing the AMPS feed ratio from 10 to 70%, and keeping other reaction conditions constant, different copolymers were synthesized. The techniques of Fourier transform infrared (FTIR) and nuclear magnetic resonance (1H-13C-NMR) spectroscopy were used for identification of functional groups and confirmation of copolymers’ structure. Intrinsic and apparent viscosity of samples were measured in aqueous sodium chloride solution under standard conditions. The anionic degree of copolymers was determined by back titration method and by13C-NMR spectroscopy. Molecular weight of copolymers was determined by the Mark-Houwink relationship. The measured molecular weight of samples showed that we have acquired a high molecular weight product. The effect of different range of shear rates on solution viscosity was evaluated. The copolymer solutions showed non-Newtonian shear thinning behavior. The performance of copolymers with respect to shear resistance and molecular weight was evaluated from industry application standpoint.

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