Preparation of Polyimide–Cellulose Composite Using Oligoimide with Ethynyl Terminals

Abstract A soluble imide oligomer (IO) (repeating number; 2 and 4) having N-phenylated melamine units and phenylethynyl terminals was prepared, and the application to polyimide composites with cellulose (CEL) crystals derived from pulp (CELp) or Halocynthia (CELh) with or without a modifier was investigated. The CELh additive up to 0.5 wt % was easily dispersed in IO matrix in solution, and thermostable (glass-transition temperature, ca. 285 °C) transparent tough film (tensile strength, ca. 169 MPa; elongation at break, ca. 8.9%; tensile modulus, ca. 4.6 GPa) was obtained, while the addition of a modifier such as cetyltrimethylammonium bromide and poly(ethylene glycol) derivatives was necessary to obtain a similar tough film for the CELp additive.