S. K. Chatterjee

Study of phenolic copolymer-acrylic copolymer-non-ionic polymer-transition metal ion interactions and formation of multicomponent complexes

Abstract Two phenolic copolymers and a methacrylic acid-methacrylamide copolymer have been synthesized and characterized by known methods. The co-ordinating groups of the respective copolymers form complexes through hydrogen bonding and ion-dipole interactions. The unreacted functional groups of the intercopolymer complexes undergo further complex formation with poly(vinylpyrrolidone) and a transition metal ion (e.g. Cu2+). The different stages in the interactions have been studied by several experimental techniques, e.g. viscometry, potentiometry, conductometry and i.r. and u.v. spectrophotometry. Formation of multicomponent complexes with distinct stoichiometries have been predicted, and some schemes have been suggested to explain the mode of interaction between the components.

Acrylic copolymer-polyelectrolyte interactions : hydrodynamic and electrochemical studies in dimethylformamide-water mixtures

Abstract Intermacromolecular complex formation has been studied between polyethyleneimine and methacrylic acid-methacrylamide copolymer in water-dimethylformamide (DMF) mixtures of different compositions. Preferential solvation coefficients ( λ C ) have been calculated for the various compositions of the solvent mixtures. At a specific composition of the solvent (e.g. 50% water + 50% DMF by volume), the intrinsic viscosity of the copolymer had a maximum value which coincided with the minimum value of λ C and the minimum value of the reduced viscosity of the complexes. Interpretations have been sought in terms of conformational change of the copolymer and the interpolymer complex at a specific composition of the solvent mixture.

Microstructure and compositional assignments of acrylamide/vinylidene chloride copolymers using one and two dimensional nuclear magnetic resonance spectroscopy

Abstract Copolymers containing acrylamide (A) and vinylidene chloride (V) units of different composition were synthesized by free radical solution polymerization. The reactivity ratios were estimated by Kelen Tudos and nonlinear error in variable methods. The triad sequence distribution in terms of A- and V-centered triads have been obtained from 13 C 1 H nuclear magnetic resonance spectroscopy. The complete spectral assignment in terms of compositional sequences of the overlapping carbon and proton spectra of these copolymers were done with the help of Distortionless Enhancement by Polarization Transfer, two-dimensional proton detected heteronuclear correlation (inverse-HETCOR) and Total Correlated Spectroscopy experiments.

FLUORESCENCE STUDIES OF COMPLEXATION OF AURAMINE O LABELED POLY(METHACRYLIC ACID) AND RELATED ACRYLIC COPOLYMERS WITH NON-IONIC HOMOPOLYMERS

Fluorescence studies of interpolymer complexation between PMA and non-ionic homopolymers (e.g. PAAm, PVP, PEO) were carried out using auramine O labeled PMA. These studies were extended to multicomponent systems as well as copolymer complexes involving methacrylic acid as one of the comonomer unit [e.g. poly(MA-co-AAm)]. The degree of linkage (q), stability constant (K) and thermodynamic parameters (e.g. ΔG°, ΔH°, and ΔS°) of copolymer and polyelectrolyte complexes were determined using Osadas method. A reasonable correlation could be obtained from electrochemical, viscometric, and fluorescence studies.

Stability Constants and Related Thermodynamic Parameters of Some Quaternary Intermacromolecular Complexes Involving Polyelectrolytes and Nonionic Homopolymers

Abstract Stability constants and related thermodynamic parameters (e.g., ΔH° and ΔS°) of some quaternary intermacromolecular complexes involving polyelectrolytes and nonionic homopolymers were determined at several temperatures. The various interacting forces involved in the complex formation are destabilized at different temperatures which are reflected in the enthalpy and entropy changes of the systems at various temperatures.

Interpolymer association between random and graft acrylic copolymers with poly(ethylene imine): effects of copolymer structure

Interpolymer complex formation has been studied between acrylamide-vinyl alcohol graft copolymer, methacrylic acid-acrylamide random copolymer and polyethylene imine. Some blends of binary homopolymer complexes having the same proportion of interacting units as in copolymer complex have also been prepared. Stability constant, degree of linkage and related thermodynamic parameters (e.g. ΔG°, ΔH° and ΔS°) have been compared for the two complexation systems using Osadas methods. The comparative study indicated considerable difference in the values of these parameters, which has been explained on the basis of copolymer structure.

Interpolymer association between phenolic copolymers and polyelectrolytes: effects of copolymer structure and hydrophobic interactions on the stability of polycomplexes

SummaryPhenolic copolymers have been prepared with two different feed compositions from some typical phenolic monomers, such as, p-Chlorophenol, p-Cresol and p-Aminophenol. They have been characterized by known methods. Some interpolymer complexes of the phenolic copolymers have been prepared with polyelectrolytes, such as poly(methacrylic acid) (PMA) and poly(ethylene imine)(PEI). The degree of linkage, stability constant, enthalpy and entropy changes of the systems were determined at several temperatures. Interpretations have been sought in terms of the various interacting forces involved in the complex formation.

Stability and thermodynamic parameters of interpolymer complexes of acrylamide/alkyl acrylate copolymers with poly(ethyleneimine): effects of microstructure and alkyl substituents of copolymers on interpolymer association

Acrylamide/ethyl acrylate (A/E) and acrylamide/butyl acrylate (A/B) copolymers of different compositions were prepared in solution by free radical polymerization. The copolymer compositions were determined from the nitrogen content in the copolymers. Interpolymer complexes of both A/E and A/B copolymers with polyethyleneimine (PEI) were prepared in DMF-water (80: 20 v/v). The stability constants and related thermodynamic parameters (e. g., ΔG 0 . ΔH 0 and ΔS 0 ) of the interpolymer complexes were determined using Osadas method. These parameters were correlated with the sequence distribution of monomer units in the copolymer chains which were obtained from 13 C{ 1 H} NMR spectroscopy. The size of the alkyl group and the microstructure of the copolymers influence the association between the copolymer and PEI, which is reflected in the stability of the interpolymer complexes.

INTERPOLYMER ASSOCIATION OF ACRYLAMIDE COPOLYMERS WITH POLY(ETHYLENEIMINE): STABILITY, THERMODYNAMIC PARAMETERS, AND THEIR CORRELATION WITH THE COPOLYMER MICROSTRUCTURE

Acrylamide/vinyl acetate and acrylamide/vinyl propionate copolymers were prepared by solution polymerization using benzoyl peroxide as the initiator. The copolymer composition was determined from the percent nitrogen in the copolymers. The stability constants and related thermodynamic parameters (e.g., ΔG°, ΔH°, and ΔS°,) of the interpolymer complexes with Poly(ethyleneimine) were determined by using Osadas method. These parameters have been correlated with the sequence distribution of monomer units in the copolymer chains which were obtained from 13C{1H} NMR spectroscopy. The sequence distribution of the comonomer units in the copolymer chains influence the association between the copolymers and the polyelectrolyte which is reflected on the stability of the interpolymer complexes.

Thermodynamic parameters of some multicomponent intermacromolecular complexes in relation to their structure and composition

SummaryFour component intermacromolecular complexes involving methacrylic acid-acrylamide copolymer, poly(ethylene imine), poly (vinyl pyrrolidone), and poly(methacrylic acid) were prepared. The stability constants and related thermodynamic parameters (e.g. ΔH° and ΔS°) of these complexes were determined at several temperatures. The enthalpy and entropy changes of the systems with temperature have been interpreted in terms of destabilization of the various interacting forces involved in complex formation.