Premium
Fatigue crack propagation of rubber‐toughened epoxies
Author(s) -
Hwang J.F.,
Manson J. A.,
Hertzberg R. W.,
Miller G. A.,
Sperling L. H.
Publication year - 1989
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.760292009
Subject(s) - materials science , natural rubber , composite material , epoxy , acrylonitrile , toughening , toughness , modulus , fracture mechanics , fracture toughness , nitrile rubber , polymer , copolymer
Epoxies containing epoxy‐terminated butadiene acrylonitrile rubber (ETBN) or amino‐terminated butadiene acrylonitrile rubber (ATBN) were prepared and studied in terms of fatigue crack propagation (FCP) resistance and toughening mechanisms. Rubber incorporation improves both impact and FCP resistance, but results in slightly lower Young's modulus and T g As T g increases, the degree of toughening decreases. Rubber‐induced shear yielding of the epoxy matrix is believed to be the dominant toughening mechanism. Decreasing fatigue resistance with increasing cyclic frequency is observed for both neat and rubber‐toughened epoxies. This result may be explained by the inability of these materials to undergo possible beneficial effects of hysteretic heating. FCP resistance is linearly proportional to M c 1/2 , where M c is the apparent molecular weight between crosslinks determined on the rubber‐toughened material. FCP resistance also increases with increasing static fracture toughness K IC . ATBN‐toughened epoxies demonstrated better fatigue resistance than ETBN‐toughened systems.