Synthesis of Copolymers of N-isopropylacrylamide and Acrylamide: The homopolymers and copolymers of IPAM and AM were synthesized by free-radical polymerization in aqueous solution at 30[degrees]C under a nitrogen atmosphere using 0.
Reaction Parameters for the Copolymerization of Acrylamide(AM) with N-isopropylacrylamide (IPAM).
The homopolymer of N-isopropylacrylamide, IPAM-100, is the most hydrophobic, with the lowest [A.
This elevation of the cloud point in the presence of SDS has been reported previously for IPAM-100 (6, 23) and is reportedly due to an association between the surfactant molecules and the N-isopropylacrylamide moieties on the copolymer chain (12).
The lowering of intrinsic viscosity with increasing temperature for the homopolymer of N-isopropylacrylamide was also reported by Heskins and Guillet (9) and later studied by Winnik (11) using the technique of nonradiative energy transfer.
The enhancement of viscosity caused by the association between the homopolymer of N-isopropylacrylamide and SDS was first reported by Elaissaf (27).
Copolymers of N-isopropylacrylamide and acrylamide (the IPAM series) have been synthesized by free radical polymerization in deionized water.
2% (~7mM) sodium dodecyl sulfate, the alkyl chain of the surfactant molecules associates with the N-isopropylacrylamide moieties on the polymer backbone (8), resulting in very high intrinsic viscosities relative to those in deionized water.
Since IPAM-40 does not have as many N-isopropylacrylamide moieties on the polymer chain as the other copolymers, it would be expected to form weaker hydrophobic associations.