Shear Piezoelectricity of Poly(L-lactide) Films Manufactured by Extrusion–Orientation: An Insight on Process–Structure–Property Relationships - Archive ouverte HAL
Article Dans Une Revue ACS Applied Polymer Materials Année : 2023

Shear Piezoelectricity of Poly(L-lactide) Films Manufactured by Extrusion–Orientation: An Insight on Process–Structure–Property Relationships

Résumé

Shear piezoelectric properties of uniaxially stretched poly(l-lactide) (US-PLA) films manufactured by an industrially relevant technique (i.e., extrusion–orientation without poling) are investigated, and specific insight on the process–structure–properties relationships is provided. Two commercially available PLA grades with d-isomer content between 2 and 4% are selected. The shear piezoelectric coefficient d14 of US-PLA films tends to increase with the draw ratio applied during the orientation stage, and a maximal d14 of 5.9 pC/N is reported. However, a dramatic degradation of piezoelectric properties could be observed at elevated draw ratios, in particular for PLA grades with low d-isomer content. Structures induced by the orientation stage are subsequently explored, and relations with shear piezoelectric properties are discussed. The mesophase is detected by DSC/WAXS up to draw ratio 4 after being replaced by strain-induced crystallization at higher draw ratios. The orientation state of the amorphous phase, mesophase, and α′-crystals is assessed by 2D-WAXS and polarized FTIR. Piezoelectric properties obtained at a moderate draw ratio are supported by the amount/orientation of each phase (partly oriented amorphous phase and fully oriented mesophase/α′-crystal phase). A model is proposed to evaluate the contribution of each phase. However, other structural parameters deserve careful attention at elevated draw ratios, in particular mechanical damage and formation of voids/cavities. 2D-SAXS analysis coupled with complementary characterizations indicates that the amount of voids/cavities controls the deterioration of shear piezoelectric performances at high draw ratios. This phenomenon is critical for highly crystalline PLA grades. A final discussion is dedicated to the quality of α′-crystals formed by current orientation conditions, a factor that could also limit the d14 coefficient of US-PLA films. This work consequently demonstrates that environmentally friendly piezoelectric films could be manufactured by a straightforward process of the plastic industry and opens up several scientific/technological perspectives for their future implementation into practical applications.
Fichier principal
Vignette du fichier
Shear Piezoelectricity of PLA.pdf (1.25 Mo) Télécharger le fichier
Origine Fichiers produits par l'(les) auteur(s)
Licence

Dates et versions

hal-04323414 , version 1 (05-12-2023)

Licence

Identifiants

Citer

Mohamed Aymen Ben Achour, Sophie Barrau, Jean-François Tahon, Mohamed Rguiti, Christian Courtois, et al.. Shear Piezoelectricity of Poly(L-lactide) Films Manufactured by Extrusion–Orientation: An Insight on Process–Structure–Property Relationships. ACS Applied Polymer Materials, 2023, 5 (12), pp.9761 - 9775. ⟨10.1021/acsapm.3c01419⟩. ⟨hal-04323414⟩
49 Consultations
103 Téléchargements

Altmetric

Partager

More