Polyesteramides used for hot melt adhesives: Synthesis and effect of inherent viscosity on properties

Polyesteramides, with different inherent viscosities, were synthesized from dimer acid, sebacic acid, ethylenediamine, and diethylene glycolamine. The effect of inherent viscosity of the polyesteramides on their thermal prope rties, such as melt viscosity, softening point, heat of fusion, glass-trans ition temperature, and low-temperature flexibility, was studied. The effect of the inherent viscosity on mechanical properties, such as tensile streng th, elongation at break, and hardness, and on adhesion properties, such as lap shear strength and T-peel strength, was also investigated. The results show that melt viscosity, tensile strength, and elongation at break increas e as the inherent viscosity increases, and that lap shear strength of the p olyesteramides also increases with increasing inherent viscosity, whereas s oftening point, glass-transition temperature, and shore D hardness of the p olyesteramides essentially do not change as the inherent viscosity increase s within a certain range. (C) 2001 John Wiley & Sons, Inc.