Synthesis and dynamic mechanical properties of heterogeneous network polymers from poly(L‐glutamic acid) and poly(oxyethylene glycol)

Abstract

AbstractHeterogeneous network polymers composed of rigid polypeptide chains and flexible polyether chains were synthesized. That is, poly(L‐glutamic acid) (PLGA) was crosslinked with poly(oxyethylene glycol) (PEG) at various carboxy/hydroxyl mole ratios K. The solubility tests and hydrolysis of heterogeneous network polymers suggest that the crosslinking reaction proceeds by esterification. The dynamic mechanical properties of these polymers(100 Hz, −100–200°C) are greatly influenced by the presence of a trace of water and the weight per cent of PLGA. In addition, some of these polymers show only one maximum in the temperature dispersion of dynamic loss modulus E″ and tan δ, although their shape is rather broad. The x‐ray photographs of these polymers show an amorphous halo or weak Debye‐Sherrer rings. These findings suggest that these polymers are not simple adducts; neverthless PLGA and/or PEG domains exist.