Thermal Properties of Stimuli-Responsive Random Copolymers of N-isopropylacrylamide and Acrylic Acid Synthesized by RAFT Polymerization

Nanocrystalline cellulose (NCC) attached homopolymers of N-isopropylacrylamide and acrylic acid (AA) as temperature- and pH-sensitive materials and also their dual-sensitive copolymers with different contents of AA were synthesized by RAFT polymerization. NCCs were obtained from microcrystalline cellulose by an acid hydrolysis process. In situ synthesis of polymers in the presence of 1 wt% of NCC was carried out at 70 °C via R-group approach. Thermal behaviour of the NCC-attached polymers was studied by differential scanning calorimetry and thermogravimetric analysis. Accordingly, polymer-grafted NCCs are thermally more stable than NCC