Preparation of Block Copolymers with a Single Tg Based on Segments of Poly(oxy‐2,6‐dimethyl‐1,4‐phenylene) and Polycarbonate of Bisphenol A

Abstract Summary: The synthesis and the properties of block copolymers based on PPO and PC segments are reported. Copolymers that have a multi‐block structure are synthesized by a polycondensation reaction that employs oligomeric PPO and PC diol terminated with phosgene or bischloroformate of bisphenol A. In the reaction scheme two steps are involved: first, the reaction of one of the oligomeric diols (PPO or PC) with the bischloroformate or phosgene; second, the oligomeric bischloroformate is reacted with the other diol. The molecular characteristics of the prepared samples are studied by SEC, 1H and 13C NMR, and FT‐IR spectroscopy. The thermal and rheological properties and the thermal stability have also been investigated by means of DSC, rotational rheometry, and TGA, respectively. Polymers that have a single glass transition temperature are obtained if low‐molecular‐weight segments are used. From a rheological point of view, these materials show a remarkably lower melt viscosity compared with a PPO homopolymer that has a comparable average molecular weight. Rheometric curves of PPO‐b‐PC (3) compared with a commercial PPO. magnified image Rheometric curves of PPO‐b‐PC (3) compared with a commercial PPO.