How the Aliphatic Glycol Chain Length Determines the Pseudoeutectic Composition in Biodegradable Isodimorphic poly(alkylene succinate-ran-caprolactone) Random Copolyesters

• Published in: Biomacromolecules Vol. 25; no. 11; pp. 7392 - 7409
• Main Authors: Safari, Maryam, Torres, Juan, Pérez-Camargo, Ricardo A., Martínez de Ilarduya, Antxon, Mugica, Agurtzane, Zubitur, Manuela, Sardon, Haritz, Liu, Guoming, Wang, Dujin, Müller, Alejandro J.
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 11.11.2024
• ISSN: 1525-7797; 1526-4602; 1526-4602
• DOI: 10.1021/acs.biomac.4c01073

We synthesize four series of novel biodegradable poly­(alkylene succinate-ran-caprolactone) random copolyesters using a two-step ring-opening/transesterification and polycondensation process with ε-caprolactone (PCL) as a common comonomer. The second comonomers are succinic acid derivatives, with variations in the number of methylene groups (n CH2) in the glycol segment, n CH2 = 2, 4, 8, and 12. The obtained copolyesters were poly­(ethylene succinate-ran-PCL) (ES x CL y ), poly­(butylene succinate-ran-PCL) (BS x CL y ), poly­(octamethylene succinate-ran-PCL) (OS x CL y ), and poly­(dodecylene succinate-ran-PCL) (DS x CL y ). We discovered a new mixed isodimorphic/comonomer exclusion crystallization in ES x CL y copolymers. The BS x CL y , OS x CL y , and DS x CL y copolymers display isodimorphic behavior. Our findings revealed a significant variation in the pseudoeutectic point position, from mixed isodimorphism/comonomer exclusion crystallization to isodimorphism with pseudoeutectic point variation from 54% to up to 90%. Moreover, we established a link between the melting temperature depression slope variation and the comonomer inclusion/exclusion balance, providing valuable insights into the complex topic of isodimorphic random copolymers.