Morphology of inorganic-organic systems consisting of polyhedral oligomeric silsesquioxanes (POSS) and polyamide 6
Résumé
Preparation of inorganic¡Vorganic hybrids made of polyhedral oligomeric silsesquioxanes (POSS) and polyamide 6 (PA6) has been attempted either by melt mixing of the two components or by in-situ polymerization of ƒÕ-caprolactam (CL) in presence of POSS. The samples have been characterized by wide angle X-ray diffraction (WAXD) and scanning electron microscopy (SEM) techniques. In the melt mixing, the possible occurrence of an intimate pair formation, favoured by some reactions between the epoxy groups of functionalized POSS molecules and the amino or carboxy groups of PA6, has been explored. Specific processing conditions (namely, high T in presence of different shear stresses) have been tested. Two different approaches for melt mixing have been used and the morphology of the corresponding systems compared. The melt-mixed pairs prepared in the microcompounder revealed a coarse phase separation, while those made in a simple mixer did not show any perceivable POSS segregation phenomenon, as evidenced by both WAXD data and SEM investigation. Similarly, the in-situ polymerization of CL in presence of POSS did not result in any POSS self-aggregation in the polyamide matrix, achieving a very fine Si dispersion of nanometric dimensions.