Characterization of free volume in particulate-filled epoxy resin by means of dynamic mechanical analysis and positron annihilation lifetime spectroscopy

✍ Scribed by A J Marzocca; A Somoza; S N Goyanes; W Salgueiro; P König

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 209 KB
• Volume: 51
• Category: Article
• ISSN: 0959-8103
• DOI: 10.1002/pi.1017

✦ Synopsis

Abstract

Dynamic mechanical measurements were carried out in composites made of quartz powder‐filled epoxy resin at frequencies between 7 and 600 Hz and temperatures between 290 and 460 K. Using the William–Landel–Ferry relationship, master curves of the dynamic moduli were obtained as a function of the frequency and the related coefficients, c^0^~1~ and c^0^~2~, were evaluated. The activation energy of the α relaxation was calculated and the influence of the filler content on the free volume was determined. The average free volumes were also measured in the composites by means of positron annihilation lifetime spectroscopy (PALS). Considering the constituent phases and the conditions of cure, the internal residual stresses in the matrix were evaluated and their influence on the free volume is discussed. Both DMA and PALS show similar results of the dependence of free volume with the filler content in the composite.

© 2002 Society of Chemical Industry