Influence of dynamic crosslinking on the morphology, crystallization, and dynamic mechanical properties of PA6,12/EVA blends

This study investigated the effect of dynamic crosslinking of polyamide 6,12 and random copolymers of ethylene and vinyl acetate blends (PA6,12/EVA) on the morphology, crystallinity, and dynamic mechanical properties. The crosslinking agent was dicumyl peroxide (DCP), and the blends were processed in a torque rheometer. The morphology depended on the DCP content, and all blends exhibited the same crystallinity index. However, with increasing crosslinking degree, the interfacial tackiness (E) values increased from 1.8 to 2.7 nm. The lamellar structures of all blends started forming at approximately 160 degrees C, close to the temperature of pure polyamide. The crosslinked phase enhanced the pseudo-elastic behavior of the blends and increased their molecular mobility activation energy. Samples with higher crosslinking degree exhibited smaller permanent deformation (0.01%) than those with low crosslinking.The authors thank Mantova Industria de tubos flexiveis, Retilox quimica for the donation of the materials, and CAPES for a scholarship to Fabricio Bondan. This work was supported by CNPq-National Council for Scientific and Technological Development, Brazil (Grant 473402/2013-0 and 308241/2015-0). The authors also thank the Brazilian Synchrotron Light Laboratory (LNLS) for the use of scientific installations (SAXS1 beamline). J.I.A. is a member of the CICPBA, La Plata, Argentina.