STRUCTURE DEVELOPMENT OF PP/PA6 BLENDS. INTERFACIAL MODIFICATIONS AND PRELIMINARY MODELING OF MACROSCOPIC PROPERTIES

Abstract

Statistical experimental design following the Box-Wilson methodology has been used by the authors for years with the main goal to correlate ultimate properties (i.e., from the macroscopic scale) with those from the microscopic scale. The aim to obtain optimal performance from heterogeneous materials based on polymers, mainly polymer blends and composites, strongly depends on the phases of the morphology involved and then on the structure and properties of the interfaces. It is because of this fact that interfacial modification agents are usually present in polymer blends and composites. The present work deals with the role played by two interfacial agents—obtained in our laboratories—as interfacial modifiers in the polyamide 6/polypropylene (PA6/PP) binary system. An experimental Box-Wilson design with two independent variables (blend composition and amount of interfacial agent) was performed, with the dependent variables being the parameters obtained from tensile tests. Mechanical property model forecasts were confirmed by phase contrast optical microscopy. The micromechanical model proposed seems to agree with the Box-Wilson forecasts, which had analysis of variance (ANOVA) from models that were satisfactory for these purposes.