Effect of Temperature and Catalyst Concentrations on the Thermal Properties of Polyamide Adhesives at Low Operating Pressure

Abstract

The polyamides used for hot-melt adhesives were synthesized from C36 dimer fatty acids and ethylenediamine under 200 mmHg and atmospheric pressures. The kinetics of the reaction rate at low pressure and the effect on the thermal properties of the produced polyamide adhesive were experimentally investigated. The effects of reaction temperature and catalyst concentration on polyamide melting point, glass transition temperature, sample weight loss and foaming height were studied. The kinetic rate constants were obtained for polymerization reaction carried out at three different reaction temperatures, 115, 120, and 135 °C, fixed mixing rate of 100 rpm and low operation pressure of 200 mmHg. Polymers produced at atmospheric pressure and reaction temperatures 140, 170, 180, and 190 °C where used to investigate the polyamide thermal properties using thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Thermal properties such as melting point, glass transition temperature and the temperature at which 5% and 10% weight loss were recorded by TGA at a heating rate of 10 C/min in N2 atmosphere. The effect of foaming height as a function of reaction temperature and catalyst concentration was measured. The analysis makes known that the reaction temperature and catalyst concentration has a noteworthy impact on the glass transition temperature, foam height and melting point and insignificant effect on the sample weight loss.