Authors: Tania E LaraCeniceros Gregorio CadenasPliego Claudia C RiveraVallejo Ramón E Díaz de LeónGómez Alejandro Coronado Enrique J JiménezRegalado
Publish Date: 2014/06/27
Volume: 21, Issue: 7, Pages: 511-
Abstract
Copolymers composed of acrylamide AM Nisopropylacrylamide NIPAM and a hydrophobic monomer either NNdihexylacrylamide DHAM or NNdioctylacrylamide DOAM were synthesized using different monomer concentrations by micellar polymerization in aqueous media Resulting polymers were characterized by molecular weight final composition lower critical solution temperature LCST and viscoelastic properties on steadyshear state The effect of the addition of an anionic surfactant sodium dodecyl sulphate SDS was studied in order to increase the viscosity of the solution Dynamic rheological studies were conducted to achieve a better comprehension of the parameters affecting the viscoelastic behavior of the polymers This study allows us to understand the relationship between the rheological behavior in aqueous solution with the relaxation time TR and plateau modulus G0 taking into account the intra e interassociations present in the multiblock copolymer hydrophobic junctions as well as the interaction between the anionic surfactant with the hydrophobic blocks and with the NIPAM units below and above the LCST of the aqueous systemThe authors would like to acknowledge the Consejo Nacional de Ciencia y Tecnología of México CONACYT for the financial support of this research through project number 46035 The authors also thank R MendozaCarrizales and J G TellezPadilla for their help in the experimental characterization
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