Fully bio-based poly(l-lactide)-b-poly(ricinoleic acid)-b-poly(l-lactide) triblock copolyesters: investigation of solid-state morphology and thermo-mechanical propertiesElectronic supplementary information (ESI) available: (S1) FTIR spectra of methyl ricinoleate and HOPRicOH, (Table S1) molecular characteristics of the synthesized HOPRicOH, (S2) SEC traces of methyl ricinoleate and HOPRicOH, (S3) SEC traces of HOPRicOH, H35, H45, H53, H63, H71 and H83, (S4) stacked FTIR spectra of HOPRicOH, PLLA

• Main Authors: Lebarb, Thomas, Ibarboure, Emmanuel, Gadenne, Benoit, Alfos, Carine, Cramail, Henri
• Format: Journal Article
• Language: English
• Published: 07.05.2013
• ISSN: 1759-9954; 1759-9962
• DOI: 10.1039/c3py00300k

In this work, a set of ABA triblock poly( l -lactide)- b -poly(ricinoleic acid)- b -poly( l -lactide) aliphatic copolyesters were prepared by consecutive AB type self-condensation and ring-opening polymerization. Condensation of methyl ricinoleate, produced from castor oil, in the presence of a small amount of 1,3-propanediol afforded ,-hydroxy-terminated poly(ricinoleic acid) with a molar mass of 11 kg mol 1 . Polymerization of l -lactide initiated from the terminal hydroxyl moieties of the ,-hydroxy-terminated poly(ricinoleic acid) led to triblock copolymers with a composition ranging from 35 to 83 wt% of PLLA. The block structure was confirmed by several techniques. The copolymers displayed a multi-step thermal degradation with a temperature corresponding to 5 wt% loss in the range 175225 C. DSC analyses showed that the PRic block had a moderate effect on PLLA melting behavior. The solid-state morphology of the so-formed copolymers was highly dependent on their chemical composition, as evidenced by SAXS and WAXD analyses. The high degree of separation of hard and soft phases was also confirmed by dynamic mechanical analysis as seen from the distinct -relaxations. Finally, the tensile properties of these block copolymers ranged from thermoplastic to elastomeric depending on their composition. Fully bio-based poly( l -lactide)- b -poly(ricinoleic acid)- b -poly( l -lactide) triblock copolymers were synthesized by a combination of AB-type self-condensation of methyl ricinoleate and ring-opening polymerization of l -lactide.