Polymerization properties of polyamide in bottom‐up prepared polyamide‐calcium carbonate composites

Polyamide/calcium carbonate composites (CaCO₃) were prepared by bottom‐up process, using a precipitated CaCO₃ with polyamide monomers followed by the polymerization of the polyamide. The composites before and after the polymerization treatment were studied by gel permeation chromatography, differential scanning calorimetry, X‐ray powder diffraction, and attenuated total reflectance—Fourier transform infrared spectroscopy. A van der Waals interaction between monomer molecules and CaCO₃ surface, which was suggested by the blue shift in IR absorption band of NH₂ and CH₂, restricted the molecular motions of monomers on the CaCO₃ surfaces to inhibit the proceeding of polymerization reactions. A resembled blue shift was also observed in the polyamide/CaCO₃ composites. Besides the hydrophilic; hydrogen bonding and ionic, interactions, the van der Waals interaction should not be ignored and had a significant effect on the polymerization reactions. POLYM. COMPOS., 35:1132–1139, 2014. © 2013 Society of Plastics Engineers