Influence of calcium carbonate nanoparticles on the crystallization of olypropylene

• Main Authors: Daniel Eiras, Luiz Antonio Pessan
• Format: Article
• Language: English
• Published: Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol) 2009-01-01
• Series: Materials Research
• Subjects: polypropylene; nanocomposites; calcium carbonate; crystallization
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392009000400024

The aim of this work was to study the influence of calcium carbonate nanoparticles in crystallization process of polypropylene. Four compositions of PP/CaCO3 nanocomposites were prepared in a co-rotational twin screw extruder machine with calcium carbonate content of 3, 5, 7 and 10 wt. (%). The tests included SEM analyzes for calcium carbonate, differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WAXD) for the nanocomposites. The results showed an increase in PP crystallization temperature and crystallinity degree, and a reduction in spherullites size. The formation of PP β phase was confirmed by DSC and WAXD results. Finally from DSC analyses under isothermal conditions it was confirmed that calcium carbonate nanoparticles have a nucleation effect in polypropylene crystallization process by reducing the half crystallization time and increasing the kinetic constant (k).