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Copolymer characterization by surface tension
Author(s) -
Allan G. Graham,
Neogi Amar Nath
Publication year - 1970
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1970.070140410
Subject(s) - copolymer , surface tension , polymer , branching (polymer chemistry) , polystyrene , solvent , materials science , polymer chemistry , propylene oxide , tetrahydrofuran , decalin , thermodynamics , chemical engineering , chemistry , organic chemistry , composite material , ethylene oxide , catalysis , physics , engineering
The use of surface tension measurements is proposed as a simple method for the determination of copolymerization ratios. The procedure depends on the parachor of the copolymer in the liquid state (∏), which is defined by ∏ = ∏ s + ∏ 0 ( w p / w s )( M s / M 0 ) for solutions and ∏ = [ DP ]∏ 0 for liquid or molten polymers, where ∏ s is the parachor of the solvent of molecular weight M s ; w p and w s are the weights of the polymer and solvent in solution; while ∏ 0 and M 0 are the parachor and molecular weight of the repeating unit of the copolymer, respectively. The validity of this relationship is demonstrated by analysis of the surface tension properties of liquid silicone polymers, polystyrene–Decalin solutions, and molten polymers as well as by the calculation of the composition of some characterized tetrahydrofuran–propylene oxide copolymers. The application of surface tension measurement is also suggested as a means of estimating the degree of chain branching in a polymer.