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Plastic deformation of low‐density polyethylene reinforced with biodegradable polylactide, Part 1: Microstructural analysis and tensile behavior at constant true strain‐rate
Author(s) -
Rezgui F.,
G'Sell C.,
Dahoun A.,
Hiver J.M.,
Sadoun T.
Publication year - 2011
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.21797
Subject(s) - low density polyethylene , materials science , composite material , polyethylene , maleic anhydride , viscoelasticity , ultimate tensile strength , modulus , creep , strain rate , deformation (meteorology) , high density polyethylene , polymer , copolymer
Abstract Blends of low‐density polyethylene (LDPE) and polylactide (PLA) were prepared by melt coextrusion. The plastic behavior of the LDPE/PLA blends was investigated at room temperature under uniaxial tension by means of a video‐controlled system. The constitutive behavior was analyzed in terms of the variations of true stress vs. true strain at constant true strain rate. With increasing concentrations of PLA, the blend show: (i) higher Young's modulus, (ii) stiffer viscoelastic response, (iii) increase of elastic limit stress, and (iv) earlier fracture. Particular attention was paid to the evolution of the volume strain with the applied strain. While dilatation begins very lately for the neat LDPE, the LDPE/PLA blends show increasing deformation damage as the PLA content is increased. Scanning electron microscopy of deformed specimens shows that cavitation occurs preferentially at the poles of the PLA particles whose adhesion to the LDPE matrix seems very weak despite the partial grafting of polyethylene chains with maleic anhydride. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers.