ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract An electron microscropic study of fracture surfaces and microtomed sections of a cured epoxy resin based on a difunctional bisphenol A type resin cured with different amounts ofm-phenylenediamine is presented. Heterogeneities in the range 5 to 100 nm are seen to be present and have relatively higher crosslink density compared to the surrounding matrix. It is observed that the fracture path is around the heterogeneity and not through it. The size of the heterogeneity is a function of curing agent concentration and also of cure cycle. The stoichiometric sample, which has the highest crosslink density and the highest glass transition temperature, has the smallest heterogeneities. On either side of stoichiometry, the heterogeneity size increases. Samples subjected to a more severe post-curing cycle have much larger heterogeneities. The possible physical basis for these differences is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01113751
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