Quiescent, flow-induced and during injection molding crystallization kinetics of HDPE nanocomposites using particles with different geometries

• Grant number: 11/23463-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2012
• End date: January 31, 2013
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Rosario Elida Suman Bretas
• Grantee: Antonio Cappelletti Ferreira
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated research grant: 06/61008-5 - Nanostructure polymeric systems: processing and properties, AP.TEM

Abstract

Regarding the crystallization kinetics, many studies on the influence of nanoclays on the polymer crystallization process and crystalline morphology have been done. It has been found that the nanoparticles act differently on each crystallization step (nucleation and growth). During nucleation, for example, some nanoparticles can be efficient nucleating agents, by reducing the entropy of the chains and by decreasing the surface energy to form the critical nuclei. On the other hand, during growth, they can act as physical barriers to the diffusion of the chains, retarding this stage by the decrease of the chains' mobility. The influence of nanoclays in the crystallization process of polymeric matrices needs further research, mainly in the presence of shear deformation. Therefore, our main objective was to study the shear-induced crystallization of HDPE nanocomposites to contribute to the elucidation of this influence.