Crystallinity and Melting of Functionalized Poly(2,6-dimethyl-1,4-phenylene) oxide (PPO)

Co-crystalline and nanoporous-crystalline poly(2,6-dimethyl-1,4-phenylene) oxide (PPO) phases can be achieved for randomly functionalized PPO. In fact, WAXD, DSC, and FTIR studies show the presence of remarkable crystallinity in PPO films with chloroacetyl (−COCH2Cl) side groups up to 17 mol %. More surprisingly, polymer melting temperature remains constant in the range 244−246 °C up to a degree of functionalization of 12 mol %. This behavior is unprecedented in polymer science and can be rationalized by side-group inclusion in PPO intrahelical crystalline channels.