The Glass Transition Temperature as a Parameter for Monitoring the Isothermal Cure of an Amine-Cured Epoxy System
Abstract
The Torsional Braid Analysis (TBA) technique is a convenient one for monitoring the cure of thermosets in terms of the glass transition temperature (Tg) as well as the times to macroscopic gelation and to vitrification. In the process of cure Tg can rise from its initial value (Tgo), through the value corresponding to its molecular gel point (gelTg), to that of the fully cured material (Tg infinity). Differential Scanning Calorimetry (DSC) is also used to measure Tg, and is especially useful in relating Tg to conversion. These techniques have been used to investigate the feasibility of using Tg as the prime parameter for monitoring the complete cure process. The objective is attractive for systems in which there is a one-to-one relationship, independent of the cure temperature, between the Tg of the material and its chemical conversion. It follows for such systems, for example, that the chemical activation energy can be determined equivalently from both the times to reach a fixed conversion and the times to reach a fixed Tg. Keywords: Cure, Vitrification, Glass transition, Kinetics, Time, Temperature, Transformation, Cure diagram, Conversion.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 15, 1989
- Accession Number
- ADA204631
Entities
People
- G. Wisanrakkit
- J. K. Gillham
Organizations
- Princeton University