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Mechanical behavior of polymethylmethacrylate with molecules oriented via simple shear
Author(s) -
Weon Jong I.,
Creasy Terry S.,
Sue H.J.,
Hsieh Alex J.
Publication year - 2005
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.20269
Subject(s) - materials science , composite material , equal channel angular extrusion , isotropy , microstructure , extrusion , fracture toughness , anisotropy , ultimate tensile strength , toughness , shear (geology) , plasticity , physics , quantum mechanics
Abstract Equal‐channel angular‐extrusion (ECAE) may greatly alter polymer properties because it creates anisotropy in the microstructure. Tensile, fracture toughness, flexure, and ballistic impact tests were performed to quantify ECAE effects on polymethylmethacrylate (PMMA). Young's modulus increased by 5% for one process condition, while strength and elongation to failure remained the same or decreased. Fracture toughness improved by 178% under a one‐pass condition. Ballistic impact resistance changes after molecular orientation by ECAE; the failure mode is along the weak planes formed by the first process. The process that subjects the specimen to a second extrusion with 180° rotation produces more isotropic and ductile ballistic impact properties. POLYM. ENG. SCI. 45:314–324, 2005. © 2005 Society of Plastics Engineers.