Supramolecular structure, phase behavior and thermo-rheological properties of a poly (L-lactide-co-ε-caprolactone) statistical copolymer

Jone M Ugartemendia; M E Muñoz; A Santamaria; J R Sarasua

doi:10.1016/j.jmbbm.2015.04.007

Supramolecular structure, phase behavior and thermo-rheological properties of a poly (L-lactide-co-ε-caprolactone) statistical copolymer

J Mech Behav Biomed Mater. 2015 Aug:48:153-163. doi: 10.1016/j.jmbbm.2015.04.007. Epub 2015 Apr 16.

Authors

Jone M Ugartemendia¹, M E Muñoz², A Santamaria², J R Sarasua³

Affiliations

¹ University of the Basque Country (UPV-EHU), Department of Mining-Metallurgy Engineering and Materials Science & POLYMAT, School of Engineering, Alameda Urquijo s/n, 48013 Bilbao, Spain.
² University of the Basque Country (UPV-EHU), Polymer Science and Technology Department, POLYMAT, Faculty of Chemistry, PO Box 1072, E-20080 Donostia-San Sebastián, Spain.
³ University of the Basque Country (UPV-EHU), Department of Mining-Metallurgy Engineering and Materials Science & POLYMAT, School of Engineering, Alameda Urquijo s/n, 48013 Bilbao, Spain. Electronic address: jr.sarasua@ehu.es.

PMID: 25933171
DOI: 10.1016/j.jmbbm.2015.04.007

Abstract

PLAcoCL samples, both unaged, termed PLAcoCLu, and aged over time, PLAcoCLa, were prepared and analyzed to study the phase structure, morphology, and their evolution under non-quiescent conditions. X- ray diffraction, Differential Scanning Calorimetry and Atomic Force Microscopy were complemented with thermo-rheological measurements to reveal that PLAcoCL evolves over time from a single amorphous metastable state to a 3 phase system, made up of two compositionally different amorphous phases and a crystalline phase. The supramolecular arrangements developed during aging lead to a rheological complex behavior in the PLAcoCLa copolymer: Around Tt=131 °C thermo-rheological complexity and a peculiar chain mobility reduction were observed, but at T>Tt the thermo-rheological response of a homogeneous system was recorded. In comparison with the latter, the PLLA/PCL 70:30 physical blend counterpart showed double amorphous phase behavior at all temperatures, supporting the hypothesis that phase separation in the PLAcoCLa copolymer is caused by the crystallization of polylactide segment blocks during aging.

Keywords: Aging; Phase structure; Poly(l-lactide-co-ε-caprolactone); Polylactide; Thermo-rheology.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Biocompatible Materials / chemistry*
Calorimetry, Differential Scanning
Caproates / chemistry*
Humans
Lactones / chemistry*
Materials Testing
Microscopy, Atomic Force
Polyesters / chemistry*
Polymers / chemistry*
Rheology

Substances

Biocompatible Materials
Caproates
Lactones
Polyesters
Polymers
poly(lactide)
caprolactone