Development of nanofibrillar morphologies in poly( l -lactide)/poly(amide) blends: role of the matrix elasticity and identification of the critical shear rate for the nodular/fibrillar transition - Archive ouverte HAL Access content directly
Journal Articles RSC Advances Year : 2018

Development of nanofibrillar morphologies in poly( l -lactide)/poly(amide) blends: role of the matrix elasticity and identification of the critical shear rate for the nodular/fibrillar transition

Abstract

Bio-based poly(L-lactide)/poly(amide-11) blends (PLA/PA11, 80/20 w/w) and poly(L-lactide)/poly(amide-6) blends (PLA/PA6, 80/20 w/w) are processed by twin-screw extrusion followed by injection-moulding and key rheological parameters controlling their morphologie are investigated. The same work is done using the same PLA modified by a multi-step reactive extrusion route with an epoxy-based chain extender to obtain modified poly(lactide)/poly(amide-11) (PLA-j/PA11 80/20 w/w) blends. The morphologies of the extruded materials and of the injection moulded parts are characterized by SEM and their formation is deeply discussed via rheological investigation to highlight the contribution of viscosity, elasticity and interfacial tension. The existence of a critical shear rate related to the transition from nodular to fibrillar morphology is highlighted and the results are in good agreement with the condition of fibrillation Ca/Ca(crit) ≥ 4. Interestingly, with the exception of PLA/PA6 specimens, all blends obviously display uniform thin-thread fibrillar morphologies after injection-moulding. Compared with pure PLA, a drastic increase of the ductility was observed in the blends exhibiting a fiberlike structure without meanwhile sacrificing the stiffness. This study confirms that, through the appropriate choice of blend components (viscosity and elasticity ratio, flow conditions, interfacial tensions) the in situ fibrillation concept provides access, at a reasonable cost, to new materials with improved thermomechanical performances, without sacrificing weight and ability to be recycled.
Fichier principal
Vignette du fichier
c8ra03339k.pdf; (2.07 Mo) Télécharger le fichier
Origin Publication funded by an institution

Dates and versions

hal-01821246 , version 1 (11-04-2024)

Identifiers

Cite

Mohammed Yousfi, Tarek Dadouche, Dimitri Chomat, Cédric Samuel, J. Soulestin, et al.. Development of nanofibrillar morphologies in poly( l -lactide)/poly(amide) blends: role of the matrix elasticity and identification of the critical shear rate for the nodular/fibrillar transition. RSC Advances, 2018, 8 (39), pp.22023 - 22041. ⟨10.1039/C8RA03339K⟩. ⟨hal-01821246⟩
36 View
0 Download

Altmetric

Share

Gmail Mastodon Facebook X LinkedIn More