Aliphatic Straight Chain Diol 1,4‐Butanediol‐Modified Hydrogenated Bisphenol A‐Type Polycarbonate

ABSTRACT To address environmental and health concerns of bisphenol A‐based polycarbonates (BPA‐PC), this study develops high‐performance green alternatives. Although hydrogenated BPA‐based polycarbonate (HBPA‐PC) shows excellent thermal and mechanical properties, its narrow processing window and limited toughness restrict practical use. Here, flexible 1,4‐butanediol (1,4‐BDO) is introduced into the rigid HBPA backbone via melt transesterification, yielding a series of PHBCs. After process optimization, the copolymers reach a maximum weight‐average molecular weight ( M w ) of 45,188 g/mol. Structural analyses confirm random copolymer formation, with glass transition temperatures ( T g ) tunable between 124.0°C and 160.5°C, consistent with Fox equation predictions. Notably, the PH 80 B 20 C exhibits approximately 150% and 167% improvements in tensile strength and elongation at break, respectively, compared to HBPA‐PC homopolymer, indicating synergistic rigidity–toughness enhancement. The copolymer also demonstrates high thermal stability ( T d,5% = 296.7°C) and excellent optical transparency (91.63%). This work provides a polycarbonate with outstanding overall performance and offers theoretical insight for designing tunable high‐performance green polymers.