Lamellar structure formation of poly(alkylacrylamides) by humid annealing

Abstract

We have reported that poly(N-dodecyl acrylamide) film forms a lamellar structure by annealing in humid condition. In this study, we synthesized several poly(N-alkyl acrylamides) with different side chain length and studied their structure after annealing in water. The X-ray scattering measurements indicated that poly(N-alkylacrylamide) with n ≥ 8 formed a lamellar structure by annealing in water. The lamellar ordering in poly(N-alkyl acrylamide) with n ≥ 15 became low because the side chain crystallization competed with a phase separation between side chains and the main chain (nanophase separation). Moreover, the copolymer of DDA with vinyl phosphonic acid formed the lamellar structure by conventional thermal annealing due to the increase of hydrophilicity of main chains which resulted in the increase of the nanophase separation force.