Thermal Characterization of Comb-like Block Copolymers Based on PCL Obtained by Combinning ROP and RAFT Polymerizations

M.D. NINAGO; A.E. CIOLINO; M.A. VILLAR; A.G.O. DE FREITAS; P.I.R. MURARO; C. GIACOMELLI

Natal

Congreso; 13° Congresso Brasileiro de Polímeros; 2015

Associação Brasileira de Polímeros

Branched polymers constitutes a special kind of macromolecular architectures in which each molecule has more than two chain ends unlike diblock or triblock copolymers, which are linear chains. This particularity imparts unique physical and chemical properties, which will definitely influence their dynamics, bulk morphologies, and crystallization processes. In this work we report the one-pot, one step synthesis of poly(hydroxyethyl methacrylate-graft-polycaprolactone)-block-poly(caprolactone) copolymers, P(HEMA-g-PCL)-b-PCL, by combining reversible addition-fragmentation chain-transfer polymerization (RAFT) and ring-opening polymerization (ROP). All comb-like copolymers were chemically characterized by Hydrogen Nuclear Magnetic Resonance (1H-NMR), Fourier Transform infrared spectroscopy (FTIR) and Size Exclusion Chromatography (SEC). Thermal behavior of the copolymers was followed by Differential Scanning Calorimetry (DSC) and their degradation process was investigated by thermogravimetric analysis (TGA). The copolymers obtained exhibited controlled molar masses between 1.000 and 100.000 g/mol and low polydispersity indexes. 1H-NMR, FTIR and SEC analysis confirmed the synthesis of the targeted copolymers. DSC analysis showed a noticeable reduction in the melting temperature comparing the comb-like copolymers with the PCL homopolymer. Nevertheless, the degradation process of the PCL was not affected.