TY - JOUR
T1 - Copolymerization of acrylamide and a hydrophobic monomer in an aqueous micellar medium
T2 - Effect of the surfactant on the copolymer microstructure
AU - Biggs, S.
AU - Hill, A.
AU - Selb, J.
AU - Candau, F.
PY - 1992/12/1
Y1 - 1992/12/1
N2 - The effects of surfactant on the radical copolymerization of acrylamide with small amounts of a hydrophobic comonomer, in an aqueous micellar medium, have been investigated. At all the surfactant and hydrophobe concentrations used here, monomers conversion-time data can be fitted by a theoretical curve calculated for the homopolymerization of acrylamide in pure water solution. Classical light scattering measurements have led to copolymer molecular weights, as a function of monomer conversion, which are in the range 1.5 × 106-3 × 106. The molecular weight is seen to depend on both the surfactant and the hydrophobe concentrations. The copolymer compositions, also as a function of conversion, have been determined by UV spectrophotometry. Comparison with a copolymerization performed in a homogeneous water/formamide mixture has shown clearly that the presence of micelles in the reaction medium increases the initial rate of hydrophobic monomer incorporation into the copolymers. As a result, the average hydrophobe incorporation in the copolymers was seen to decrease toward the feed composition as a function of conversion, the larger the decrease the higher the hydrophobe to surfactant ratio. Analysis of all the above data has led to the proposal of a mechanism of copolymerization in an aqueous micellar medium.
AB - The effects of surfactant on the radical copolymerization of acrylamide with small amounts of a hydrophobic comonomer, in an aqueous micellar medium, have been investigated. At all the surfactant and hydrophobe concentrations used here, monomers conversion-time data can be fitted by a theoretical curve calculated for the homopolymerization of acrylamide in pure water solution. Classical light scattering measurements have led to copolymer molecular weights, as a function of monomer conversion, which are in the range 1.5 × 106-3 × 106. The molecular weight is seen to depend on both the surfactant and the hydrophobe concentrations. The copolymer compositions, also as a function of conversion, have been determined by UV spectrophotometry. Comparison with a copolymerization performed in a homogeneous water/formamide mixture has shown clearly that the presence of micelles in the reaction medium increases the initial rate of hydrophobic monomer incorporation into the copolymers. As a result, the average hydrophobe incorporation in the copolymers was seen to decrease toward the feed composition as a function of conversion, the larger the decrease the higher the hydrophobe to surfactant ratio. Analysis of all the above data has led to the proposal of a mechanism of copolymerization in an aqueous micellar medium.
UR - http://www.scopus.com/inward/record.url?scp=0006376838&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0006376838
VL - 96
SP - 1505
EP - 1511
JO - Journal of Physical Chemistry
JF - Journal of Physical Chemistry
SN - 0022-3654
IS - 3
ER -