Okra (Abelmoschus esculentus) Fibre Based PLA Composites: Mechanical Behaviour and Biodegradation

摘要

Okra (Lady’s finger, Abelmoschus esculentus) fibres were introduced in a poly(lactic) acid (PLA) polymer matrix as short fibres (5–10 mm), in amounts variable between 10 and 30 %wt. For this purpose, both untreated and alkali treated okra fibres were used. The obtained composites, in view of the envisaged application for sustainable packaging purposes, has been tested morphologically, mechanically and subjected to chemical characterisation, while the biodegradation profile has been studied. The introduction of fibres in the polymer matrix always resulted in a higher stiffness of the obtained composite. The addition of okra fibre to PLA results in an increased ability of the PLA matrix to crystallize due to the nucleation effect of the okra fibre, and this effect was more evident in the composites produced with alkali treated fibres. The biodegradation process was accelerated by the addition of higher contents of fibres into the composites due to preferential degradation of the fibres themselves: this effect was increased when composite fibres are alkali-treated.