Showing papers by "Roger Fayt published in 1993"

Multifractal analysis. A new method for the characterization of the morphology of multicomponent polymer systems

Abstract: It has been demonstrated that use of polymeric emulsifiers under usual processing conditions in the melt state is a powerful technique for preparing polymer alloys. Digitized representation of optical micrographs of thin sections of blends of a low-density polyethylene and polystyrene (20 wt % PE-80 wt % PS) containing 2 and 5 wt % of two hydrogenated polybutadiene-polystyrene block copolymers exhibit different degrees of homogeneity as well as different morphological structures which can be studied by a multifractal analysis. We show how these differences are reflected in the f(α) spectrum of singularities which can be obtained by a box counting method in the canonical approximation. We have found a correlation between the f(α) curves and the mechanical properties of the corresponding samples: the samples which area the less multifractals have the best mechanical properties. © 1993 John Wiley & Sons, Inc.

From incompatible poly(aryl ether sulfone)/polyamide 4.6. blends to new impact resistant alloys by a synergistic combination of a block copolymer emulsifier and an impact modifier

Abstract: The compatibilization and impact modification of blends of a relatively new engineering plastic polyamide 4.6 (PA 4.6) and a poly(aryl ether sulfone) (PSU) are investigated. PSU-b-PA6 block copolymers, which can be easily synthesized by ring opening polymerization of ϵ-caprolactam in the presence of a commercial PSU, were found to be very efficient emulsifiers for these incompatible blends. Small amounts (1–4%) of copolymer are sufficient to significantly reduce the particle size and to improve the tensile and impact properties. Combinations of the copolymer and an impact modifier (ethylene-propylene rubber grafted with maleic anhydride) are synergistic and high impact PSU/PA 4.6 alloys are obtained in that way.