Strain-induced deformation mechanisms of polylactide plasticized with acrylated poly(ethylene glycol) obtained by reactive extrusion

Kui Wang, Berit Brüster, Frédéric Addiego, Georgio Kfoury, Fatima Hassouna, David Ruch, Jean Marie Raquez, Philippe Dubois

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

The deformation mechanisms of plasticized polylactide containing inclusions of poly(Acryl-polyethylene glycol) involved chain orientation, crystallization and crystal destruction. The initial spherical inclusions were transformed into ellipsoids with a decreased density. This work aimed at identifying the tensile deformation mechanisms of an original grade of plasticized polylactide (pPLA) obtained by reactive extrusion. This material had a glass transition temperature of 32.6°C and consisted of a polylactide (PLA) matrix grafted with poly(acryl-poly(ethylene glycol)) (poly(Acryl-PEG)) inclusions. pPLA behaved like a rubber-toughened amorphous polymer at 20°C, and its tensile behavior evolved toward a rubbery semicrystalline polymer with increasing temperature. The drawing of pPLA involved orientation of amorphous and crystalline chains, crystallization, and destruction of crystals. It was found that crystal formation and crystal destruction were in competition below 50°C, resulting in a constant or slightly decreasing crystallinity with strain. Increasing temperature enhanced crystal formation and limited crystal destruction, resulting in an increased crystallinity with the strain level. Drawing yielded a transformation of the initial spherical poly(Acryl-PEG) inclusions into ellipsoids oriented in the tensile direction. This mechanism may engender the formation of nanovoids within the inclusions due to a decreased density, assumed to be responsible for the whitening of the specimen.

Original languageEnglish
Pages (from-to)1544-1554
Number of pages11
JournalPolymer International
Volume64
Issue number11
DOIs
Publication statusPublished - 1 Nov 2015
Externally publishedYes

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Keywords

  • Chain orientation
  • Crystallinity
  • Plastification
  • Polylactide
  • Tensile testing

ASJC Scopus subject areas

  • Polymers and Plastics

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