Effect of Pimelic Acid Treatment on the Crystallization, Morphology, and Mechanical Properties of Isotactic Polypropylene/Mica Composites

Pimelic acid (PA) is used as a new surface modifier for mica (MC). The effects of PA treatment on the crystallization, morphology, and mechanical properties of isotactic polypropylene (iPP)/MC composites have been investigated. FTIR analysis reveals that PA reacted with phlogopite MC, and pimelates are formed during the treatment. The results of wide angle X-ray diffraction, differential scanning calorimetry, and polarized light microscopy prove that PA-treated MC induces a large amount of beta-iPP and decreases the spherulite size of iPP. The results of SEM show that PA treatment improves the orientation and dispersion of MC plates in the matrix. The notched impact strength of the composites is improved dramatically by PA-treated MC. The superior toughness is ascribed to the more ductile beta spherulites, preferential orientation of MC plates, small spherulite size, and improved dispersion of MC plates in the matrix. POLYM. COMPOS., 31:1572-1584, 2010. (C) 2009 Society of Plastics Engineers