Effect of amino silane coupling agent on crystallization behavior of polyamide 612/glass fiber composites

Abstract

Abstract Amino silane coupling agents (0, 0.5, 1.0, and 2.0wt %) were added to polyamide 612 (PA612)-based composites reinforced with short glass fibers (GFs) to investigate the effect of the additives on the crystallization kinetics, which were tested using injection molding. The isothermal crystallization activation energies and the kinetic parameters of the crystallization processes of the samples were determined using the Arrhenius, Avrami, and Lauritzen–Hoffman models. The kinetic calculations revealed that the addition of a silane coupling agent significantly benefitted the GFs in terms of slowing down the isothermal crystallization rate of PA612. Moreover, treating the surface of GF-reinforced PA612 composites with a silane coupling agent induced optimum performance of the injection-molded PA612 parts. This is because the GFs enhanced the mechanical properties while the coupling agent delayed crystallization and improved the GF-substrate adhesion. Moreover, compared with a coupling agent-free PA612/GF composite, the activation energy of crystallization was reduced by a factor of over 1.5 from ΔEa -92.84 to ΔEa -163.55 J/mole with the addition of a coupling agent. The experimental results demonstrated that the PA612/GF composite with 1.0wt % coupling agent displayed the highest absolute value of crystallization activation energy (|ΔEa|).