Side chain effect of rodlike polyglutamate, poly(γ-stearyl α, l-glutamate)

Long side chains of polyglutamate were introduced to reduce the melting temperature and to increase the solubility of the polymer in many organic solvents. The side chains, however, interdigitate each other and generate inhomogeneous monolayers at the air/water interface or different domains in bulk. Intercrossing of the side chain was investigated with temperature gradient Langmuir–Blodgett technique. The surface area/monomer and surface pressure increased with temperature for the range of 23–50°C. However, only variable temperature FT-IR shows the conformational change after the side chain melting at 60°C. The spacing of the rod and the side chain intercrossing were calculated from these experimental data and compared with short side chain polyglutamate polymers.