Oxidative degradation of polylactide (PLA) and its effects on physical and mechanical properties

Damien Rasselet (1) , Alexandre Ruellan (1) , Alain Guinault (1) , Guillaume Miquelard-Garnier (1) , Cyrille Sollogoub (1) , Bruno Fayolle (1)

1 PIMM - Laboratoire Procédés et Ingénierie en Mécanique et Matériaux

The thermo-oxidative degradation of polylactide (PLA) films was studied between 70 and 150 C. It was shown that the oxidative degradation of PLA leads to a random chain cission responsible for a reduction of the molar mass. These molar mass changes affect Tg and the degree of crystallinity, and it was found that Tg decreases according to the Fox-Flory theory whereas the degree of crystallinity increases due to a chemicrystallization process. A correlation between molar mass and strain at break during oxidation has been established: PLA displays a brittle behavior when Mn falls below 40 kg mol 1 in agreement with relationships linking the critical value for embrittlement with the molar mass between entanglements.

Mots clés: Polylactic acid; Polylactide; Ageing; Thermo-oxidation; Embrittlement

Domaines: Polymères; Science des matériaux [cond-mat.mtrl-sci]; Mécanique des matériaux [physics.class-ph]; Mécanique des matériaux [physics.class-ph]

Damien Rasselet, Alexandre Ruellan, Alain Guinault, Guillaume Miquelard-Garnier, Cyrille Sollogoub, et al.. Oxidative degradation of polylactide (PLA) and its effects on physical and mechanical properties. European Polymer Journal, 2014, 50 (1), pp.109-116. ⟨10.1016/j.eurpolymj.2013.10.011⟩. ⟨hal-00977105⟩