Poly(N‐isopropylacrylamide). I. Interactions with sodium dodecyl sulfate measured by conductivity

Abstract

Conductometric titration of poly(N‐isopropylacrylamide) (polyNIPAM) with sodium dodecyl sulfate (SDS) gave two apparent transitions labeled C1 and C2. The C1 transition was independent of polyNIPAM concentration in the 0.05–0.3 wt % range, whereas C2 was proportional to the polymer concentration. C1 corresponded to the onset of binding of surfactant with polymer. Arguments based on a simple mass action model for micellization are presented to show that C2, the second transition, is not due to any simple explanation such as being the point above which only free micelles are formed with surfactant addition. The cloud point of polyNIPAM increased with the amount of bound surfactant. This was attributed to electrostatic contribution of bound sulfate groups to the increased solubility of polyNIPAM. © 1993 John Wiley & Sons, Inc.

RNA-sensitive N-isopropylacrylamide/vinylphenylboronic acid random copolymer

“…[41,[44][45][46] We were also unsuccessful in determining the molecular-weights of NIPA-co-VPBA copolymers by GPC, using THF as the mobile phase. As a result, we decided to measure the molecular weight by a viscosimetric method.…”

N-Isopropylacrylamide andN-Isopropylmethacryl-amide: Cloud Points of Mixtures and Copolymers

“…The behavior of polyNIPAM in water and the effect of various factors such as solvent composition, [12] structure of the group in the side chain, [13] addition of cosolutes (salts, surfactants), [14] copolymerization with charged [15] or uncharged [16] comonomers etc. were investigated extensively.…”

Observation of Phase Transition of Thermo-Responsive Poly(NIPA)–PEI Block Copolymers by STM

“…Note that we have used a chain transfer agent (MAA) which terminates polymerization, which adds carboxylic acid at this end as expected. Note that, as mentioned in the literature, there have been significant controversies in the molecular weight determination of poly(NIPA) by different techniques [20][21][22][23]. Note that we also tried to measure the molecular weights of homo-and copolymers that we have synthesized by different methods including viscocity measurements, direct titration, and GPC.…”