Evaluation of thermal and mechanical behavior of some anionic polyesteramide copolymers

A series of aliphatic polyesteramide copolymers were synthesized through by anionic ring opening copolymerization of є–caprolactam (CLA) with є–caprolactone (CLO) using the rotational molding technique. The thermal characteristics of the prepared polyesteramide copolymers have been studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and dynamic mechanical analysis (DMA). The tensile, flexural and impact strength tests were performed for copolymers characterization from point of view of mechanical properties. The DSC results showed that the presence of comonomer (CLO) affects the melting temperature (Tm), crystallization temperature (Tc) and degree of crystallinity (αDSC) (first and second heating scan) of the polyesteramide copolymers which decrease proportionally to the content of the CLO in the initial monomer feed. The data related to onset decomposition temperatures and Tpeak1 and Tpeak2 values indicates that the polyesteramide copolymers are more thermally stable than nylon 6 homopolymer. Also, dynamical mechanical analysis revealed that introduction of ester sequence into nylon 6 backbone decreased both the storage modulus and the glass transition temperature of resulted polyesteramide copolymers. The elongation at break and impact strength of the polyesteramide copolymers increase significantly with increasing initial CLO content while a decrease of their tensile and flexural properties occurs. The results related to polyesteramide copolymers were compared with those obtained for nylon 6 homopolymer.