POLYMER ENCAPSULATION OF GLASS FILLER IN TERNARY PP PA-6/GLASS BLENDS/

The morphology and rheology of ternary isotactic polypropylene (PP)/po lyamide-6 (PA-6)/glass blends is investigated and contrasted with the behavior of two-component (binary) PP/PA-6 blends. Injection molded sa mples of binary blends exhibit an interlayer slip morphology for both PP and PA-6 as the matrix and the blend shear viscosity is lower than expected from a rule of mixtures. The morphology of ternary blends is dependent on the choice of the matrix phase. In ternary blends with a PA-6 matrix, the PP domains and glass fibers are separately dispersed within the matrix. In ternary blends with a PP matrix, the PA-6 is mai nly found surrounding (encapsulating) the glass fibers, and the extent of the interlayer slip morphology is reduced. Variations in glass sur face treatment, blending time, and order of addition did not affect th e rapid encapsulation of glass by the PA-6. A reduction in blending te mperature, below the peak PA-6 melting temperature, hinders encapsulat ion.