Charakterisierung von Epoxidharzformulierungen für Verbundwerkstoffe - Einfluss von Aushärtegrad und Aushärteweg

Translated title of the contribution: Characterization of epoxy resin formulations for composites - Influence of curing degree and curing method

Markus Wolfahrt

Research output: ThesisDoctoral Thesis

1449 Downloads (Pure)

Abstract

As a result of their high specific strength and stiffness, advanced polymer-matrix composites have been successfully applied as construction materials for lightweight structures, in particular for primary and secondary structures in commercial transport aircrafts. However, for the composite behaviour under compressive loads and under impact and fatigue loading conditions, the properties of the polymer matrix are of significant importance. Hence, the analysis of different influential factors such as raw material constituents and resin formulations, the processing and cure conditions as well as the curing degrees and moisture contents on the mechanical properties of cured neat resins is necessary. The main objective of this work was, first to clarify the complexities of the degree of cure and the curing path on the key neat resin properties for advanced polymer ma-trix composites. These include storage modulus as a function of temperature, glass transition temperature and fracture energy using commercial epoxy resin formula-tions both in dry and wet conditions. In addition to the thermo-calorimetric measurements for assessment of curing behaviour and the degree of cure via differential scanning calorimetry, the dynamic mechanical analysis under 3-point bending and torsion loading of the specimens as well as fracture mechanical tests are used to form the main element of the test methodical execution. While the dynamic mechanical tests were carried out to determine the thermo-mechanical storage moduli as a function of temperature, Ef(T) and Gto(T), and specifically of the storage modulus values, Ef(23) at 23 °C and Gto(30) at 30 °C, the fracture mechanical tests were per-formed to obtain the fracture energy, GIC. Second, an analogous test program was carried out to evaluate the applicability and limitations of the results of the character-istic neat resin properties on specimens made of fibre reinforced composites, again depending on the degree of cure and the moisture content.
Translated title of the contributionCharacterization of epoxy resin formulations for composites - Influence of curing degree and curing method
Original languageGerman
QualificationDr.mont.
Supervisors/Advisors
  • Fink, Johannes, Assessor B (internal)
  • Lang, Reinhold, Assessor A (internal)
Publication statusPublished - 2009

Bibliographical note

embargoed until null

Keywords

  • epoxy resin
  • fibre-reinforced composites
  • degree of cure
  • cure path

Cite this