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Hardness of irradiated hydroxyethyl methacrylate copolymer at elevated temperatures
Author(s) -
Lu K. P.,
Fu Y. K.,
Lee Sanboh
Publication year - 2009
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.29680
Subject(s) - materials science , methacrylate , copolymer , irradiation , activation energy , polymer chemistry , (hydroxyethyl)methacrylate , annealing (glass) , polymer , 2 hydroxyethyl methacrylate , arrhenius equation , indentation hardness , kinetics , chemical engineering , composite material , chemistry , microstructure , physics , nuclear physics , engineering , quantum mechanics
The hardness of irradiated hydroxyethyl methacrylate (HEMA) copolymer at elevated temperatures was measured using a microhardness tester. The hardness increases with annealing time, and is attributed to the defects present in the molecular chains. The defects that control the hardness are related to the entanglement of polymer chain and follow a first order kinetics process. The relaxation time satisfies the Arrhenius equation, with constant activation energy of 25 kJ/mol independent of the irradiation dose. The results were compared with those of PMMA and LiF single crystals reported in the literature. The present findings are useful in the study of soft contact lens, kidney dialysis system, drug delivery system, and artificial liver support system. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009