Introducing cryomilling for reliable determination of resin content and degree of cure in structural carbon fibre reinforced thermoset composites

Research output: Contribution to journalArticlepeer-review


  • Nessa Fereshteh-Saniee
  • Neil Reynolds
  • Peter R. Wilson
  • Ken N. Kendall

Colleges, School and Institutes

External organisations

  • WMG, University of Warwick,


A novel material preparation method is presented that facilitates accurate measurement of the degree of cure and resin content within carbon fibre reinforced polymer composites (CFRPs). When using conventional specimen preparation for standard thermal analysis, it is demonstrated that the experimentally-obtained enthalpy of reaction and resin content varies significantly between analyses. Measurement uncertainties arise because small specimen volumes are extracted from materials that exhibit both macroscopic inhomogeneity and physical discontinuities. To address this issue, representative sample volumes of aligned CFRPs were first cryogenically milled to develop a homogeneous powder before smaller specimens were extracted. The variation in obtained enthalpy of reaction between analyses was reduced from 23% (for conventional specimen extraction) to 1% following cryomilling. The accuracy in measurement of degree of cure for the compression moulding parts was improved 7 times. Further, subsequent FTIR analysis proved that cryomilling did not affect the final chemical structure of the cured material.


Original languageEnglish
Pages (from-to)197-204
JournalComposites Part A: Applied Science and Manufacturing
Early online date6 Jan 2018
Publication statusPublished - 1 Apr 2018


  • A. carbon fibre , A. thermosetting resin , D. thermal analysis , E. powder processing