How the Aliphatic Glycol Chain Length Determines the Pseudoeutectic Composition in Biodegradable Isodimorphic poly(alkylene succinate-<i>ran</i>-caprolactone) Random Copolyesters
Maryam Safari, Juan Luis Tirado Torres, Ricardo A. Pérez‐Camargo, Antxon Martı́nez de Ilarduya, Agurtzane Múgica, Manuela Zubitur, Haritz Sardón, Guoming Liu, Dujin Wang, Alejandro J. Müller
Abstract
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.