New Approach to Determine the Phase Transition Temperature, Cloud Point, of Thermoresponsive Polymers

作者：Tebaldi Marli L^*; Fiel Luana A; Santos Amilton M; Guterres Silvia S; Pohlmann Adriana R

来源：Journal of Macromolecular Science Part A-Pure and Applied Chemistry, 2013, 50(6): 581-587.

DOI：10.1080/10601325.2013.784171

• Triblock copolymers
• cloud point
• poly(N-vinylcaprolactam)
• poly(t-butyl acrylate)
• poly(acrylic acid)
• multiple light scattering

In this study, a novel method to determine the cloud point temperature variation in aqueous solutions of thermoresponsive homo- and copolymers was developed. Poly(N-vinylcaprolactam) (PVCL) and triblock copolymers of poly(t-butyl acrylate-co-acrylic acid)-b-poly(N-vinylcaprolactam)-b-(t-butyl acrylate-co-acrylic acid) (P[(tBA-co-AA)-b-PVCL-b-P(tBA-co-AA)] were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization and used as models. The incorporation of AA units (hydrophilic segments) into the polymeric chain of PVCL influenced the phase transition, increasing the cloud point temperature of the final copolymer. The cloud point temperatures of the PVCL and the triblock copolymer P(tBA-co-AA)-b-PVCL-b-P(tBA-co-AA) were determined by measuring the transmittance of aqueous solutions of the polymers in a Turbiscan Lab instrument in the range of 29 to 40 C. This is the first study in which Turbiscan Lab is used to determine the cloud point temperature.

• 出版日期2013-1-1