Physical and mechanical properties of nano-CaCO3/PP composites modified with acrylic acid

Abstract

Nano-CaCO3/polypropylene (PP) composites modified by the reactive monomer acrylic acid (AA) with or without the initiator dicumyl peroxide (DCP) were prepared using a two-step method. The effects of nano-CaCO3 and AA on the physical and mechanical properties of nano-CaCO3/PP composites were investigated. Differential scanning calorimetry (DSC) results showed that the incorporation of nano-CaCO3 increased the crystallisation temperature as a result of the heterogeneous nucleation effect of nano-CaCO3 on PP, and induced the formation of β phase PP. The addition of AA further increased the crystallisation temperature of PP and the intensity of β phase PP. The mechanical tests indicated that nano-CaCO3 could simultaneously reinforce and toughen PP, and the mechanical properties of nano-CaCO3/PP composites were higher than those of micro-CaCO3/PP composites. In addition, incorporation of AA further increased the mechanical properties of the composites. In the presence of DCP, a small amount of AA could increase markedly the mechanical properties of nano-CaCO3/PP composites.