scholarly journals Direct Synthesis and Characterization of Photo-Crosslinkable Biodegradable PLA-PEG-PLA Ttiblock Copolymer with Methacrylates Functions by Green Montmorillonite Clay Catalyst

2020 ◽  
Vol 14 (4) ◽  
pp. 474-480
Author(s):  
Mohamed Benachour ◽  
◽  
Aslya El-Kebir ◽  
Amine Harrane ◽  
Rachid Meghabar ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Cationic Polymerization ◽  
Direct Synthesis ◽  
Average Molecular Weight ◽  
Montmorillonite Clay ◽  
Synthesis And Characterization ◽  
Molecular Weights ◽  
One Step ◽  
Clay Catalyst

Di-methacrylated PLA-PEG-PLA triblock copolymers of polylactide and polyethylene glycol were synthesized in one-step process by bulk cationic polymerization of lactide in the presence of PEG with different average molecular weights, using Maghnite-H+, an acidic montmorillonite clay, as a solid non-toxic catalyst. The obtained di-methacrylated copolymer was analyzed by 1H NMR and DSC. The effect of Maghnite-H+ proportions and PEG average molecular weight on the copolymerization and methacrylation yields and on average molecular weight of the resulting copolymers was studied.

Synthesis and Properties of Uniform Polyisoprene Networks. I. Synthesis and Characterization of α,ω-Dihydroxy-Polyisoprene

1976 ◽  
Vol 49 (2) ◽  
pp. 303-319 ◽  
Author(s):  
M. Morton ◽  
L. J. Fetters ◽  
J. Inomata ◽  
D. C. Rubio ◽  
R. N. Young
Keyword(s):  
Molecular Weight ◽  
Physical Properties ◽  
Soluble Fraction ◽  
Synthesis And Characterization ◽  
Molecular Weights ◽  
Molecular Weight Distributions ◽  
Weight Distributions ◽  
The Subject

Abstract The results of this study are the first to show that high-1,4 linear α,ω-dihydroxypolydienes can be synthesized with (a) predictable molecular weights, (b) narrow molecular weight distributions, and (c) high functionalities. Using the functionalized polyisoprenes prepared in this work, a series of networks was prepared with a purified triisocyanate as the chain linking agent. The soluble fraction in these networks ranged from 4.6 to 1.6 per cent. The characteristics and physical properties of these networks will be the subject of a forthcoming publication.

Synthesis and Characterization of Coumarin–Trioxane–Urea Copolymers

1996 ◽  
Vol 8 (2) ◽  
pp. 295-300 ◽  
Author(s):  
D I Brahmbhatt ◽  
B R Hirani
Keyword(s):  
Molecular Weight ◽  
Elemental Analysis ◽  
Average Molecular Weight ◽  
Synthesis And Characterization ◽  
Number Average Molecular Weight ◽  
Molar Ratios

4-methyl-7-hydroxycoumarin trioxane urea (MHCTU) copolymers were prepared by copolycondensation of 4-methyl-7 hydroxycoumarin (MHC), trioxane (T) and urea (U) in the presence of 2 M HCl/H2SO4 as a catalyst with different molar ratios of reacting monomers. The copolymers were characterized by elemental analysis, IR spectral and TGA studies. The number average molecular weight ( Mn) of all the produced copolymers was determined by non-aqueous titrimetry.

scholarly journals Synthesis and Characterization of Colored Polyureas

2004 ◽  
Vol 1 (1) ◽  
pp. 51-56 ◽  
Author(s):  
M. G. Patel ◽  
K. R. Desai ◽  
H. S. Patel
Keyword(s):  
Electrical Conductivity ◽  
Molecular Weight ◽  
Room Temperature ◽  
Average Molecular Weight ◽  
Conductometric Titration ◽  
Spectral Studies ◽  
Synthesis And Characterization ◽  
Disperse Dyes ◽  
Number Average Molecular Weight

Various disperse dyes based onm-phenylenediamine have been prepared. These dyes then polycondensation with 4,4'-Diphenyl methane diisocyanate. The resultant colored polyureas were characterized by N content, IR spectral studies, Number Average Molecular Weight (Mn) estimation by nonaqueous conductometric titration and thermogravimetry. All the polyureas were subjected to measure electrical conductivity at room temperature.

Synthesis and characterization of poly(coumarin-urethane)s

1994 ◽  
Vol 6 (3) ◽  
pp. 257-262
Author(s):  
D I Brahmbbatt ◽  
L Jayabalan ◽  
Harshad D Patel
Keyword(s):  
Molecular Weight ◽  
Elemental Analysis ◽  
Vapour Pressure ◽  
Condensation Reaction ◽  
Average Molecular Weight ◽  
Spectral Studies ◽  
Synthesis And Characterization ◽  
Molecular Weight Determination ◽  
Number Average Molecular Weight

Poly(coumarin-urethane)s (PCUs) were prepared by the condensation reaction of 3,3'-dihydroxy-6,6'-methylcnebiscoumarin (DHMBC) with various diisocyanates. All the poly(coumarin-urethane)s were characterized by elemental analysis, IR spectral studies, number average molecular weight determination (by vapour pressure osmometry), viscosity studies and thermogravimetry.

Synthesis and Characterization of Some New Esters Containing Heterocyclic and Derived From Azo Dyes

2019 ◽  
Vol 9 (02) ◽  
Author(s):  
Zena G. Alrecabi ◽  
Zainab Amer ◽  
Naeemah Al-Lami
Keyword(s):  
Schiff Base ◽  
13C Nmr ◽  
Azo Dyes ◽  
Spectral Methods ◽  
Anthranilic Acid ◽  
Heterocyclic Compounds ◽  
Synthesis And Characterization ◽  
Cooh Group ◽  
Molecular Weights

This study including prepared new colored esters containing heterocyclic with high molecular weights. In the first part of work we synthesized azo dyes [1,2] from the reaction p-toluidine with β-naphthol and o-nitro phenol, thin we synthesized Schiff bases [3,4] by the reaction anthranilic acid with benzaldehyde and dimethyl benzaldehyde. The reaction azo dyes (contain OH group) with Schiff base (contain COOH group) these led to produce the new colored esters [A1-A4]. The second part of work was modification the (C=N-) group in esters to heterocyclic compounds by reacting with phenyl iso cyanide to produce new β-lactam [B1-B4] and with anthranilic acid to get new hydroquinazoline [C1-C4]. All these compounds were characterized by physical properties and spectral methods FTIR, 1H-NMR and 13C-NMR.

Direct Synthesis and Characterization of Copper(II) 1‐Phenyltetrazol‐5‐olates

2021 ◽  
Author(s):  
Sergei Voitekhovich ◽  
Alexander Lyakhov ◽  
Ludmila Ivashkevich ◽  
Alexander Lavrov ◽  
Ludmila Lavrenova ◽  
...  
Keyword(s):  
Direct Synthesis ◽  
Synthesis And Characterization

scholarly journals Semi-Crystalline Hydrophobic Polyamidoamines: A New Family of Technological Materials?

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1018
Author(s):  
Massimo Marcioni ◽  
Jenny Alongi ◽  
Elisabetta Ranucci ◽  
Mario Malinconico ◽  
Paola Laurienzo ◽  
...  
Keyword(s):  
Maximum Stress ◽  
Water Resistance ◽  
Prolonged Exposure ◽  
Water Soluble ◽  
Synthesis And Characterization ◽  
Molecular Weights ◽  
New Family ◽  
Methylene Groups ◽  
Methane Flame

The hitherto known polyamidoamines (PAAs) are not suitable as structural materials because they are usually water-soluble or swellable in water. This paper deals with the synthesis and characterization of semi-crystalline hydrophobic PAAs (H-PAAs) by combining different bis-sec-amines with bis-acrylamides obtained from C6–C12 bis-prim-amines. H-PAAs were initially obtained in a solution of benzyl alcohol, a solvent suitable for both monomers and polymers. Their number average molecular weights, M¯n, which were determined with 1H-NMR by evaluating the percentage of their terminal units, varied from 6000 to >10,000. The solubility, thermal properties, ignitability and water resistance of H-PAAs were determined. They were soluble in organic solvents, semi-crystalline and thermally stable. The most promising ones were also prepared using a bulk process, which has never been previously reported for PAA synthesis. In the form of films, these H-PAAs were apparently unaffected by water. The films underwent tensile and wettability tests. They showed similar Young moduli (260–263 MPa), whereas the maximum stress and the stress at break depended on the number of methylene groups of the starting bis-acrylamides. Their wettability was somewhat higher than that of common Nylons. Interestingly, none of the H-PAAs considered, either as films or powders, ignited after prolonged exposure to a methane flame.

scholarly journals Synthesis and characterization of different soybean oil-based polyols with fatty alcohol and aromatic alcohol

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 491-499
Author(s):  
Fukai Yang ◽  
Hao Yu ◽  
Yuyuan Deng ◽  
Xinyu Xu
Keyword(s):  
Molecular Weight ◽  
Soybean Oil ◽  
Retention Time ◽  
Ring Opening ◽  
Isoamyl Alcohol ◽  
Synthesis And Characterization ◽  
Intermolecular Force ◽  
H Nmr ◽  
Epoxy Groups

Abstract In this article, five kinds of soybean oil-based polyols (polyol-E, polyol-P, polyol-I, polyol-B, and polyol-M) were prepared by ring-opening the epoxy groups in epoxidized soybean oil (ESO) with ethyl alcohol, 1-pentanol, isoamyl alcohol, p-tert-butylphenol, and 4-methoxyphenol in the presence of tetrafluoroboric acid as the catalyst. The SOPs were characterized by FTIR, 1H NMR, GPC, viscosity, and hydroxyl numbers. Compared with ESO, the retention time of SOPs is shortened, indicating that the molecular weight of SOPs is increased. The structure of different monomers can significantly affect the hydroxyl numbers of SOPs. Due to the large steric hindrance of isoamyl alcohol, p-hydroxyanisole, and p-tert-butylphenol, SOPs prepared by these three monomers often undergo further dehydration to ether reactions, which consumes the hydroxyl of polyols, thus forming dimers and multimers; therefore, the hydroxyl numbers are much lower than polyol-E and polyol-P. The viscosity of polyol-E and polyol-P is much lower than that of polyol-I, polyol-B, and polyol-M. A longer distance between the molecules and the smaller intermolecular force makes the SOPs dehydrate to ether again. This generates dimer or polymers and makes the viscosity of these SOPs larger, and the molecular weight greatly increases.

Direct synthesis and characterization of the Fe3+ analogue of Naβ″-alumina

1986 ◽  
Vol 21 (2) ◽  
pp. 619-624 ◽  
Author(s):  
M. F. Hochella ◽  
T. D. Ketcham ◽  
D. G. Pickles
Keyword(s):  
Direct Synthesis ◽  
Synthesis And Characterization
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