Isothermal Crystallization of Poly(ε–Caprolactone) PCL in Three‐Armed Copolymers

GIAROLI, MARÍA CAROLINA; REDONDO, FRANCO LEONARDO; FREITAS, ANDRÉIA M. S.; BRANCALLION, OSWALDO; BENDER, CAROLINE R.; BECK, THAÍSSA S.; DE FREITAS, AUGUSTO G. O.; CIOLINO, ANDRÉS EDUARDO; NINAGO, MARIO DANIEL

MACROMOLECULAR SYMPOSIA

WILEY

Año: 2022 vol. 406

1022-1360

Branched copolymers are a special class of polymeric materials in which arereflected the combined effects of polymer segments and architecturalconstraints of the branched architecture. In this work, three-armed graftcopolymers, poly (hydroxyethyl methacrylate-graft-poly(caprolactone),[P(HEMA-g-PCL)]3, are synthesized by combination of reversibleaddition-fragmentation chain-transfer (RAFT) and ring openingpolymerization (ROP) mechanisms in a one-pot/one-step protocol. Theresulting macromolecules are characterized by 1H Nuclear MagneticResonance (NMR), size exclusion chromatography (SEC), differentialscanning calorimetry (DSC), and thermogravimetric analysis (TGA). Thepreliminary results indicate the success of the methodology and are inagreement with literature reports. In addition, DSC isothermal crystallizationare performed, and Avrami’s theory is employed in order to obtain kineticsparameters of interest, such as the half-life for the crystallization process(t1/2), the bulk crystallization constant (k), and the Avrami’s exponent (n).Thermal analysis evidences a noticeable reduction in the melting temperaturecompared with linear PCL homopolymer. However, the presence of branchesdoes not modify the values of the maximum degradation temperaturessignificantly. Finally, the synthesized copolymers adopt a two-dimensionalcrystallization type (disk and cylindrical).