Characterization and Aqueous Solution Behavior of Novel Thermo-associating Polymers

Abstract

Novel thermo-associative water-soluble polymers (PAVD) have been prepared by copolymerizing N-vinylcaprolactam (NVCL) with various amounts of sodium 2-acrylamido-2-methylpropanesulphonic acid (NaAMPS) and crosslinker divinylbenzene (DVB) using the micellar copolymerization technique. The copolymers were characterized by ¹H-NMR, FT-IR, elemental analysis and GPC. The thermo-associating behavior of these copolymers was studied in aqueous solution by means of rheological experiments. It was shown that when the content of NaAMPS in copolymers was up to a certain value, the thermo-thickening behavior was clearly observed in semi-dilute aqueous solution due to the hydrophobic aggregation between VCL units. The influence of different parameters such as copolymer and salt concentrations, on the thermo-thickening behavior of the copolymers was investigated. The thermo-associative phenomenon was further analyzed by studying the relationship between the critical associative temperature and the lower critical solution temperature. More importantly, the copolymer aqueous solution exhibited excellent thermal stability at 100°C for a period of two months.

Keywords:

• N-vinylcaprolactam
• thermo-thickening behavior
• thermo-associative polymer
• thermal stability

Acknowledgment

We would like to thank the financial support from NSF of China (No. 41072094) for this work.