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Gradient Structure Polymer Obtained from a Homogeneous Mixture: Synthesis and Mechanical Properties
Author(s) -
Noblet Guillaume,
Désilles Nicolas,
Lecamp Laurence,
Lebaudy Philippe,
Bunel Claude
Publication year - 2006
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.200500467
Subject(s) - double bond , photopolymer , materials science , polymer , irradiation , temperature gradient , polyurethane , composite material , homogeneous , polymer chemistry , polymerization , thermodynamics , physics , quantum mechanics , nuclear physics
Summary: The synthesis of a polymer that exhibits a gradient in mechanical properties, by means of a new method recently developed in our laboratory, is described. The synthesis involves two commercial resins, Laromer® LR 8986 and Laromer® LR 9000. In a first step, an acrylic double bond photopolymerization gradient is created under UV exposure thanks to the decay of UV light intensity through the sample thickness. In a second step, a thermal crosslinking reaction is realized to form a polyurethane network in order to set the obtained gradient. The experimental conditions required to obtain and keep the gradient are investigated by FT‐IR and UV spectroscopies. Thus, an 80% acrylic double bond conversion gradient is obtained in the ultimate 5 mm thick material. Dynamic mechanical analysis reveals an important difference between both sides of the material, the irradiated surface being hard at ambient temperature, meanwhile the underside remains soft.Acrylic double bond conversion after 3 min of irradiation at 30 °C on materials of various thicknesses.