Thermal curing of aerospace sealant

• Main Author: Teo, Wee Lin.
• Other Authors: Marc Jean Medard Abadie
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering::Materials::Non-metallic materials
• Online Access: http://hdl.handle.net/10356/43797
• Institution: Nanyang Technological University

In this project, we investigated the curing behaviour of DAPCO 18-4F, a silicone based sealant used in the aerospace industry. Through this, we hope to find out the optimum sealant-to-hardener ratio, a suitable kinetic model for the curing behaviour and also kinetic parameters involved in the curing. Differential scanning calorimetry was chosen to study the curing at both isothermal and non isothermal conditions. For non isothermal case, curing was done at various heating rates and for non isothermal case; the heating was done at different constant temperatures. In both cases, samples were confirmed to be fully cured before the experimental data was used in subsequent calculations. For non-isothermal curing, both the Kissinger and Ozawa methods were used to determine the activation energy before using the equation proposed by Malek to determine a suitable kinetic model which was found to be the Sestak Berggren kinetic model. Simulation with experimental results has shown it to be fairly accurate in modelling the curing behaviour. For isothermal curing, the Kamal model was used to model the curing behaviour, however the simulation has shown that the model is not suitable for DAPCO 18-4F. In addition, determination of the activation energy across all three formulations for both isothermal and non-isothermal curing has shown that the optimum sealant-to-hardener ratio is 100-7 wt%/wt%.