Preparation and structure‐property studies on copolypeptides of γ‐methyl glutamate‐glutamic acid and γ‐methyl glutamate–γ‐benzyl glutamate

A series of copolypeptides of poly(methyl glutamate‐glutamic acid) (PBC) and poly(methyl benzyl glutamate) (PMB) were prepared from homopolymeric poly(methyl D‐glutamate) (PMDG) via a variety of synthetic routes. Following their characterization, these copolymers were then investigated via dynamic mechanical spectroscopy, stress‐strain analysis (wet and dry), and wide‐angle x‐ray scattering (WAXS). It was found that the copolymers could be prepared from homopolymeric PMDG with minimal chain degradation or side reactions. The mechanical properties of either series did not follow a simple trend, in that specific properties such as Young's modulus went through either a maximum or minimum with composition ratio of the two comonomers. based on the WAXS studies, some rationalization for this behavior was established. Specifically, the nature of the side‐chain interaction, and therefore chain packing, was strongly affected by comonomer ratio.