Synthesis and characterization of a novel polyesteramide from modified jatropha seed oil, dimer acid and ethylenediamine as hot melt adhesive

Abstract

This work deals with the synthesis and characterization of a novel polyesteramide (PEA) hot melt adhesive (HMA) using dimer acid, ethylenediamine, and modified jatropha seed oil. Jatropha seed oil was initially reacted with diethanolamine to prepare N,N-bis(2-hydroxyethyl) jatropha oil fatty amide (HEJA), having hydroxyl end groups. HEJA was reacted with dimer acid as a partial replacement of ethylenediamine. Ethylenediamine was replaced up to 30% by HEJA, on molar basis. Prepared PEA HMAs were characterized for mechanical, thermal, rheological, and adhesion properties. Increased replacement of ethylenediamine by HEJA led to decreased tensile strength, melting temperature, enthalpy of melting, crystallization temperature, enthalpy of crystallization, glass transition temperature, lap shear strength, T-peel strength, and viscosity. This was due to the reduction in hydrogen bond formation capacity, and thus the intermolecular forces of attraction of the ester and secondary amide linkages as compared to primary amide linkages, and the increased distance between ester linkages as compared to the primary amide linkages, was caused due to the bulky nature of HEJA. However, HMAs prepared using HEJA will have better low temperature flexibility due to low Tg; and better adhesion process due to the lower viscosity and melting temperature.