Erosion of the molecular network in the amorphous layers of polyethylene upon high- strain deformation
Article dans une revue avec comité de lecture
Author
BARTCZAK, Zbigniew
303306 Polska Akademia Nauk = Polish Academy of Sciences = Académie polonaise des sciences [PAN]
303306 Polska Akademia Nauk = Polish Academy of Sciences = Académie polonaise des sciences [PAN]
GRALA, Magdalena
303306 Polska Akademia Nauk = Polish Academy of Sciences = Académie polonaise des sciences [PAN]
303306 Polska Akademia Nauk = Polish Academy of Sciences = Académie polonaise des sciences [PAN]
Abstract
Samples of linear polyethylene, neat and crosslinked by irradiation with electron beam, were subjected to heavy plastic deformation by plane-strain compression up to the true strain exceeding 2 (deformation ratio λ > 8) at room temperature. Structural studies of deformed samples and investigation of long-term strain recovery demonstrated that the deformation of the neat, non-crosslinked HDPE is completely reversible above the melting point of the crystalline phase, provided that the applied true strain does not exceed e = 1.0 (λ = 2.7). At higher applied strains, e > 1, an irreversible deformation component emerged gradually, and at e = 2.1 (λ = 8.2), the permanent, truly irreversible, residual strain was approx. eres = 0.36 (λ = 1.4). In contrast, samples of crosslinked HDPE above Tm exhibited complete reversibility of deformation, irrespectively of an applied strain, and eres ≈ 0. The source of permanent irreversible strain component in neat HDPE is a deformation-induced partial destruction of the molecular network of entangled chains within amorphous interlamellar layers. The principal mechanism found was chain disentanglement, which was supplemented by a very limited chain scission. In the case of crosslinked materials, the dense and relatively homogeneous molecular network appeared robust enough to avoid any damage. Consequently, the strain appeared here fully reversible upon melting of crystalline phase.
Files in this item
Related items
Showing items related by title, author, creator and subject.
-
Article dans une revue avec comité de lectureOKAMBA-DIOGO, Octavie; VERDU, Jacques; FERNAGUT, François; GUILMENT, Jean; PERY, Frédérique; FAYOLLE, Bruno; RICHAUD, Emmanuel (Elsevier, 2016)Polyamide 11 films stabilized by Irganox® 1098, Irganox® 1010 or Irganox® 245 were subjected to thermal oxidation at 110°C. The residual phenol content was assessed by comparing three analytical methods:high performance ...
-
Article dans une revue avec comité de lectureFRANCOIS-HEUDE, Alexandre; LEPROVOST, Julien; HENINGER, Michel; MESTDAGH, Helene; DESNOUX, Eric; COLIN, Xavier; RICHAUD, Emmanuel (Elsevier, 2013)Analysis of volatile organic compounds (VOCs) during PP thermal oxidation under three oxygen partial pressures (0%, 21% and 100% of atmospheric pressure) at 140 C was performed by proton transfer reaction coupled with ...
-
Article dans une revue avec comité de lectureThe thermal oxidative ageing of vinyl ester and unsaturated polyester was studied at temperatures ranging from 120 to 160°C and oxygen pressures ranging from 0.02 to 2.0 MPa. The oxidation of both materials was shown to ...
-
Article dans une revue avec comité de lectureThis work reports the thermal oxidation of DGEBA resins totally cured with cycloaliphatic (isophorone diamine) or with linear aliphatic (trioxa-tridecanediamine or TTDA) diamine hardener. Chemical changes (carbonyl build-up) ...
-
Article dans une revue avec comité de lectureThermal oxidation of three epoxy resins prepared from flexible or rigid prepolymers and hardeners was studied by monitoring epoxy mechanical and physical changes. The physical changes were followed by mass measurements, ...