Preparation and properties of a composite made by barium sulfate-containing polytetrafluoroethylene granular powder

Barium sulfate (BaSO4)-containing polytetrafluoroethylene (PTFE) granular powder was prepared through a two-phase emulsion dispersion granulation method. Because of its large bulk density, small average particle size, narrow particle size distribution, and superior powder flowability, the granular powder is suitable for use in automatic molding machines. The effects of granulation on the tensile strength of the BaSO4/PTFE composite were investigated, and the composite’s microstructures were characterized and analyzed using scanning electron microscopy. All these indicated that the granulation could make BaSO4 disperse more homogeneously in PTFE and reduce many defects in molded articles. So the properties of the BaSO4/PTFE composites made by the granular powder were superior to the composite obtained from the nongranular powder. The tensile strength and elongation of the composite obtained from the granular powder could be achieved to a level of 19.4 MPa and 420%, respectively.