Supramolecular polymer gels formed from polyamidine and random copolymer of n‐butyl acrylate and acrylic acid.

概要

We have prepared the amidinium‐carboxylate salt bridge‐based supramolecular polymer gels from random copolymer of n‐butyl acrylate and acrylic acid and a linear polyamidine having N,N′‐di‐substituted acetamidine group in the main chain. The supramolecular polymer gel with equimolar amounts of carboxy and amidine groups shows a high G′ value of 1.6 MPa at 25°C. In contrast, the gel prepared from the carboxy polymer and linear polyethyleneimine instead of the polyamidine shows liquid‐like fluidity with a G′ value of 0.01 MPa at 25°C. The robustness of the amidine‐based supramolecular polymer gels is attributed to the high stability of the amidinium‐carboxylate salt bridge. Replacing the random copolymer with carboxy‐terminated telechelic poly(n‐butyl acrylate) results in a significant decrease in G′ as well as |η*|, which may arise from the difference in the network structure due to the arrangement of carboxy groups.