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Abstract

Variation of thermal diffusivity and specific heat of a general-purpose epoxy during curing was investigated experimentally. The thermoset materials are particularly difficult to characterize during their polymerization on the one hand because of the presence of exothermic chemical reactions and on the other hand because their thermophysical properties depend both on the temperature and on the degree of cure. Thanks to a method in periodic mode associated with very sensitive thermal sensors, one could separate and measure the variations of thermal diffusivity with temperature and degree of cure during the thermoset polymerisation. In addition, a heat capacity analysis was performed during the cure using a temperature modulated calorimeter. Thermal diffusivity measurements show a non linear increase of more than 100% during the cure of an epoxy/glass fiber composite while heat capacity changes are less than 10%.

Keywords

thermal property thermal diffusivity heat capacity curing thermoset resins glass fiber

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References

1. Lobo, H. and Cohen C. 1990. “Measurement of thermal conductivity of polymer melts by the line-source method,” Polymer Engineering and Science, 30:65-70.

2. Farmer, J.D. and Covert E.E. 1994. “Transverse thermal conductance of thermosetting composite materials during their cure,” J. Thermophysics and Heat Transfer, 8:358-365.

3. Pusatcioglu, S.Y. , Fricke A.L. and Hassler J.C. 1979. “Variation of thermal conductivity and specific heat during cure of thermoset polyesters,” J. Applied Polymer Science, 24:947-952.

4. Sourour, S. and Kamal M.R. , 1976. “A new apparatus to measure the thermal conductivity and diffusivity of thermoplastic and thermosetting polymers,” Polymer Engineering and Science, 16:480-488.

5. Guyonvarch, G. 1995. “Analysis and Optimisation of Coupled Heat Transfer During Molding of Composite Materials by the Resin Transfer Molding (RTM) Process,” Ph.D. thesis, ISITEM—University of Nantes, France.

6. Baïlleul, J.L. 1997. “Optimisation of Cure Cycle for Thick Parts of Composite Material,” Ph.D thesis, ISITEM—University of Nantes, France.

7. Scott, E.P. 1989. “Estimation of the Thermal and Kinetic Properties Associated with Carbon Epoxy Composite Materials During and After Curing,” Ph.D. thesis, Michigan State Univ., East Lansing, Michigan.

8. Angström, A.J. 1863. Phil. Mag., vol. 25: 130.

9. Sommier, A. 1998. “Thermal Properties Measurement of Thermoset Material during Curing and On-line Cure Monitoring using Microdielectrometry,” Ph.D. thesis, ISITEM—University of Nantes, France.

10.

10. Carslaw, H.S. and Jaeger J.C. 1959. Conduction of Heat in Solids, p. 109, New York, Oxford Univ. Press.

Thermal Property Measurements During Curing of Thermoset Resins Using Steady Periodic Conditions

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