New Experimental Data for Enthalpy of Reaction and Temperature- and Degree-of-Cure-Dependent Specific Heat and Thermal Conductivity of the Hercules 3501-6 Epoxy System

Abstract

Measurements of enthalpy of reaction and temperature- and degree-of-cure-dependent specific heat and thermal conductivity are reported for a commercial epoxy resin system (Hercules 3501-6 resin). A Differential Scanning Calorimeter (DSC) was used to determine heat of reaction and specific heat while the line source method was employed for thermal conductivity. The measured heat of reaction of 508±19J/g is compared with conflicting data previously reported by others. Specific heat is reported in the temperature range of 320–550 K and at degrees of cure 20, 40, 74 and 100%. Both raw data and polynomial curve fits are reported. Thermal conductivity is reported in the temperature range of 298–500 K and at degrees of cure 11.5, 51.2 and 100%. These data are found to be independent of degree of cure within experimental error over this range. The data are represented by

K _e = (0.202 + 6:122 × 10⁻³ T− 4:8107 × 10⁻⁵ T ² + 1.248 × 10⁻⁷ T ³− 1.043 × 10⁻¹⁰ T ⁴)(W/mK)

The fractional uncertainty (based on two standard deviations) of the measured enthalpy of reaction, specific heat and thermal conductivity is estimated to be less than ±3.7, ±5 and ±11.8%, respectively.