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Light scattering from reacting polymer systems. Associating polymers in a good solvent
Author(s) -
Burchard Walther
Publication year - 1990
Publication title -
makromolekulare chemie. macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 0258-0322
DOI - 10.1002/masy.19900390116
Subject(s) - molar mass , virial coefficient , polymer , compressibility , thermodynamics , particle (ecology) , solvent , chemistry , modulus , polystyrene , molar concentration , light scattering , scattering , polymer chemistry , materials science , physics , organic chemistry , optics , composite material , oceanography , geology
The forward scattering of light allows determination of the osmotic modulus (=inverse osmotic compressibility), which in good solvents is a measure of repulsive forces among the particles in solution but also depends on the molar mass of the particle. The osmotic modulus increases with concentration if the particle weight remains constant. The increase differs for particles of different architecture and can for c < 3c* be described by structure specific g‐factors, where g is defined through A 3 =gA 2 2 M w with A 2 and A 3 being the 2nd and 3rd virial coefficients. For associating systems in a good solvent also the particle weight increases with c. A procedure is suggested which allows within limits a correction of the measured apparent molar mass M̄ app (c) for the true molar mass M̄ w (c) at the concentration c. Three examples are discussed in detail.