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

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.

1996 ◽  
Vol 8 (2) ◽  
pp. 295-300 ◽  
Author(s):  
D I Brahmbhatt ◽  
B R Hirani

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.


2004 ◽  
Vol 1 (1) ◽  
pp. 51-56 ◽  
Author(s):  
M. G. Patel ◽  
K. R. Desai ◽  
H. S. Patel

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.


2004 ◽  
Vol 1 (5) ◽  
pp. 256-262 ◽  
Author(s):  
Kanuprasad Dahyalal Patel ◽  
Dhirubhai J. Desai ◽  
Manish M. Morekar ◽  
Yogesh Shrikant Tilak

N,N'-Dimethylol thiourea-formaldehyde (DMTUF) resin having the methylol group (CH2OH) has been prepared and characterized. The condensation of DMTUF resin with Phenol (P) was carried out in the presence of alcoholic alkali catalyst at varying ratios of DMTUF: P, namely 1:1, 1:1.5 and 1:2. The resultant DMTUFP resin was characterized by elemental analysis, IR spectral studies, number average molecular weight (M¯n) estimated by non-aqueous conductometric titration, and thermo gravimetry. The curing study of DMTUFP resin with hexamethylene tetramine (HMTA) was monitored by differential scanning calorimetry (DSC) and kinetic parameters were evaluated. Glass-reinforced composites based on the DMTUFP-HMTA system have also been prepared and characterized.


2002 ◽  
Vol 67 (7) ◽  
pp. 523-530 ◽  
Author(s):  
Raghu Prasad ◽  
Seema Gupta

2+2 Cyclocondensation of 1,7-diaminoheptane with ?-diketones, viz 2,3-butanedione, 3,4-hexanedione or 4,4?-dimethylbenzil, in the presence of Mg2+, Ca2+, Sr2+ and Ba2+ ions as templates yields a series of complexes of the type [ML(X2)](where L = N4 macrocycle having a 22-membered ring and X=Cl or NCS). The resulting complexes were characterized by elemental analysis conductance measurements and IR and 1H-NMR spectral studies.


2020 ◽  
Vol 14 (4) ◽  
pp. 474-480
Author(s):  
Mohamed Benachour ◽  
◽  
Aslya El-Kebir ◽  
Amine Harrane ◽  
Rachid Meghabar ◽  
...  

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.


1997 ◽  
Vol 9 (4) ◽  
pp. 457-460
Author(s):  
K B Patel ◽  
K R Desai ◽  
H S Patelk

Four various poly(urethane-urea)s (PUUs) were prepared by polycondensation of 3-aminophenol with various diisocyanates. The resultant poly(urethane-urea)s were characterized by elemental analyses, IR spectral studies, number average molecular weight ( Mn) estimated by non-aqueous conductometric titration and thermogravimetry. The electrical properties of these polymers have also been measured at room temperature.


2012 ◽  
Vol 8 ◽  
pp. 1505-1514 ◽  
Author(s):  
Aurica Farcas ◽  
Ana-Maria Resmerita ◽  
Andreea Stefanache ◽  
Mihaela Balan ◽  
Valeria Harabagiu

The paper reports the preparation of a poly[2,7-(9,9-dioctylfluorene)-alt-5,5'-bithiophene/PS-βCD] (PDOF-BTc) polyrotaxane copolymer, through a Suzuki coupling reaction between the 5,5'-dibromo-2,2'-bithiophene (BT) inclusion complex with persilylated β-cyclodextrin (PS-βCD), and 9,9-dioctylfluorene-2,7-bis(trimethylene borate) (DOF) as the blocking group. The chemical structure and the thermal and morphological properties of the resulting polyrotaxane were investigated by using NMR and FT-IR spectroscopy, TGA, DSC and AFM analysis. The encapsulation of BT inside the PS-βCD cavity results in improvements in the solubility, as well as in different surface morphology and thermal properties of the PDOF-BTc rotaxane copolymer compared to its noncomplexed PDOF-BT homologue. In contrast, the number-average molecular weight (M n) of PDOF-BTc rotaxane copolymer indicated lower values suggesting that the condensation reaction is subjected to steric effects of the bulkier silylated groups, affecting the ability of the diborate groups from the DOF molecule to partially penetrate the PS-βCD cavity.


2014 ◽  
Vol 92 (6) ◽  
pp. 525-532 ◽  
Author(s):  
Jon Ward ◽  
Saif Al-Alul ◽  
Shane Harrypersad ◽  
Daniel A. Foucher

The distannyl-bridged poly bis(dimethylstannyl)ferrocene, 5, was synthesized through either the metal-catalyzed intermolecular dehydrogenative condensation of the bis(dimethylstannyl)ferrocene, 6, or the ring-opening polymerization of the distannane-bridged [2]ferrocenophane, 7. Both polymerization strategies yielded compounds displaying NMR (1H, 13C, 119Sn) evidence for a distannane bridged polymer. A modest moderate molecular weight (GPC; Mw = 9.5 × 104 Da, PDI = 1.76) was found for polymer 5 prepared by dehydrogenative condensation. Polymer 5 displayed electronic communication (≈ 0.2 V) between neighbouring iron centers, similar to those reported for monobridged ferrocenyl stannane polymers. Polymer 5 was further characterized by UV–vis spectroscopy, elemental analysis, and modeled with the related distannyl-8 and tristannyl-9 bisferrocenes using DFT at the SDD level of theory.


Sign in / Sign up

Export Citation Format

Share Document