TY - JOUR A1 - Erdmann, Maren A1 - Trappe, Volker A1 - Sturm, Heinz A1 - Braun, Ulrike A1 - Dümichen, Erik T1 - Cure conversion of structural epoxies by cure state analysis and in situ cure kinetics using nondestructive NIR spectroscopy N2 - Non-isothermal heating rate kinetics was applied to two epoxy resin systems. In situ near-infrared (NIR) measurements were taken with a heatable NIR cell which allowed the cure to be monitored by characteristic absorption bands. An autocatalyzed reaction of the nth order was shown to describe the epoxy conversion curves. Differential Scanning Calorimetry (DSC) was used as a complementary method. The kinetic models developed by both NIR and DSC are in good accordance with experimental epoxy conversion in the in situ NIR setup for single and multiple cure temperature ramps. A linear calibration curve of the characteristic absorption bands of epoxy normalized to aromatic vibrations was introduced. The curing degree of structural epoxies that were cured according to an industrial temperature cure profile was determined by NIR using the calibration curve. The epoxy conversions of the structural components showed good agreement with the experimental in situ NIR. Several degrees of cure for structural specimens were evaluated by NIR and residual reaction enthalpy by DSC. We present the non-destructive NIR spectroscopy as an alternative to determine fast and non-destructive epoxy conversion, particularly suitable for high degrees of cure on structural components. KW - Epoxy resin KW - Curing kinetics KW - In situ near-infrared (NIR) spectroscopy KW - Differential scanning calorimetry (DSC) PY - 2017 UR - http://www.sciencedirect.com/science/article/pii/S0040603117300205 U6 - https://doi.org/10.1016/j.tca.2017.01.010 SN - 0040-6031 SN - 1872-762X VL - 650 SP - 8 EP - 17 PB - Elsevier B.V. AN - OPUS4-39123 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -