A new method for the insertion of aliphatic moieties into bisphenol A (BPA) polycarbonate (PC) by reactive blending with ethylene carbonate (ETC) has been developed. By this route, new polymeric materials with modified thermal and rheological properties have been synthesized; the structure of the poly(ether‐co‐carbonate)s prepared can be controlled using different ETC/PC molar ratios. Using model compounds and selective degradation reactions, the different chemical structures of the aliphatic units inserted into PC backbone were identified. ETC/PC molar ratios below 1 afforded both aliphatic–aromatic carbonate and ether groups, while higher ETC/PC molar ratios afforded aliphatic–aromatic ether and aliphatic–aliphatic carbonate groups. The co‐polymers prepared by the new process were clear without discoloration or opacity. The thermal analyses of the co‐polymers showed that, by the insertion of aliphatic moieties, it is possible to modulate the glass transition temperature (Tg) in a 30°C range. A decreased melt viscosity of the co‐polymers was also observed and therefore an improved processability should be expected with respect to standard PC. The reaction with aliphatic carbonates can be also considered as a promising chemical recycling process for PC scraps, through the synthesis of monomers such as bis(hydroxyethyl)ether of BPA. This monomer has already been used for the preparation of co‐polyesters of terephthalic acid with high Tg and thermal stability. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 39820.