Real time dielectric investigations of phase separation and cure in rubber modified epoxy resin systems

✍ Scribed by Costas G. Delides; David Hayward; Richard A. Pethrick; Argyris S. Vatalis

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 630 KB
• Volume: 28
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(92)90125-l

✦ Synopsis

Real time dielectric and rheological measurements are reported for mixtures of carboxylterminated butadiene acrylonitrile in epoxy resins obtained by curing either with diaminodiphelmethane at 80 ° or triethylenetetramine at 30: with the diglycidylether of bisphenol-A. A good correlation is observed between the time required for gelation determined by the two methods. The mixture is initially homogeneous but soon undergoes phase separation. The occurrence of phase separation is marked by the appearance of a new dielectric feature which is ascribed to the motion of ionic charges in the conducting occluded rubbery phase. This is the first time that the dielectric technique has been used as a real time monitor of phase separation processes.