Advanced thermal analysis and transport properties of stereocomplex polylactide

Abstract : The originality of this work is based on analysis of physical and physicochemical properties of polylactide mixtures of different chirality (poly L-lactic acid and poly D-lactic acid) and on the influence of the chirality on the amorphous phase’s properties. The materials mixtures are elaborated from two homopolymers (PLLA and PDLA) according to two methods; solution casting or extrusion. Totally amorphous and isotropically crystallized materials with more or less confined amorphous phase were studied. It is shown that a stereocomplex crystalline phase can be obtained only under certain experimental conditions. The results of the thermal and permeation analyzes showed that the PLLA / PDLA mixture improved certain properties of the material, namely higher barrier properties towards liquid water and gases were obtained compared to parent homopolymers. In order to study the molecular mobility of amorphous phases, physical aging and structural relaxation (α and β relaxation), the Cooperative Rearrangement Region (CRR) concept has been applied. It has been shown that the amorphous phases of the homopolymers and the mixture have exactly the same properties at the glass transition and in the vitreous state when the materials are totally amorphous.
Document type :
Theses
Complete list of metadatas

Cited literature [199 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-02272914
Contributor : Abes Star <>
Submitted on : Wednesday, August 28, 2019 - 12:18:07 PM
Last modification on : Thursday, November 14, 2019 - 10:11:27 AM

File

nagihanvarol.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-02272914, version 1

Citation

Nagihan Varol. Advanced thermal analysis and transport properties of stereocomplex polylactide. Materials. Normandie Université, 2019. English. ⟨NNT : 2019NORMR019⟩. ⟨tel-02272914⟩

Share

Metrics

Record views

501

Files downloads

51