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Water‐soluble copolymers. I. Synthesis of model dextran‐ g ‐polyacrylamides by Fe(II)/H 2 O 2 initiation and characterization by aqueous size exclusion chromatography
Author(s) -
McCormick Charles L.,
Park Lee Soon
Publication year - 1981
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.1981.070260525
Subject(s) - copolymer , aqueous solution , size exclusion chromatography , grafting , acrylamide , dextran , polymer chemistry , viscometer , polyacrylamide , gel permeation chromatography , molar mass distribution , hydrolysis , chemistry , shear thinning , intrinsic viscosity , rheology , materials science , viscosity , chromatography , organic chemistry , polymer , composite material , enzyme
Model graft copolymers were synthesized by grafting acrylamide onto dextran ( M̄ w = 500,000) utilizing the Fe(II)/H 2 O 2 initiation system. Aqueous size exclusion chromatography (SEC) was used to determine the effects of changing reaction parameters on hydrodynamic dimensions of the resulting graft copolymers. It was also possible to optimize reaction conditions yielding the highest viscosity graft copolymer with the least amount of homopolyacrylamide and unreacted substrate. The molecular structures of the graft copolymers were determined by elemental analysis, SEC, and solution viscometry. Selective hydrolysis of the dextran backbone allowed determination of average molecular weight of acrylamide grafts, number of grafting sites, and average molecular weight of the graft copolymers. Rheological studies indicated viscosity and pseudoplastic behavior were largely related to the graft length of the polyacrylamide side chains.