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Solution Properties of Water-Soluble “Smart” Poly(N-acryloyl-N′-ethyl piperazine-co-methyl methacrylate)
Soft Materials Laboratory, Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, 1-Nanyang Walk, 637616, Singapore
Received: 28 November 2011; in revised form: 21 December 2011 / Accepted: 5 January 2012 / Published: 5 January 2012
Abstract: Water-soluble copolymers of N-acryloyl-N′-ethylpiperazine (AcrNEP) with methyl methacrylate (MMA) were synthesized to high conversion by free-radical solution polymerization. The composition of the copolymers was determined using Fourier Transform Infra-red Spectroscopy (FTIR). Copolymers containing AcrNEP content above 44 mol% were readily soluble in water and exhibited the critical solution temperature behavior. The copolymers were strongly responsive to changes in pH of the external medium due to the presence of tertiary amine functions that could be protonated at low pH. The influence of various factors such as copolymer composition, pH, temperature, salt and surfactant concentration on the LCST of the copolymers were systematically studied. The intrinsic viscosity of the copolymers in dimethyl formamide decreased with increase in temperature due to a decrease in thermodynamic affinity between polymer chains and solvent molecules. The viscosity behavior of the copolymers in sodium chloride solution was similar to that of classical polyelectrolytes and hydrophobically modified polyacrylate systems.
Keywords: water-soluble polymers; piperazine; viscosity; critical solution temperature
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MDPI and ACS Style
Deen, G.R. Solution Properties of Water-Soluble “Smart” Poly(N-acryloyl-N′-ethyl piperazine-co-methyl methacrylate). Polymers 2012, 4, 32-45.
Deen GR. Solution Properties of Water-Soluble “Smart” Poly(N-acryloyl-N′-ethyl piperazine-co-methyl methacrylate). Polymers. 2012; 4(1):32-45.
Deen, G. Roshan. 2012. "Solution Properties of Water-Soluble “Smart” Poly(N-acryloyl-N′-ethyl piperazine-co-methyl methacrylate)." Polymers 4, no. 1: 32-45.