Silicate Fiber Polymer Composite

A thermoplastic composite comprising a discontinuous fiber phase dispersed in a continuous polymer phase:

• (a) the discontinuous phase comprising an effective increasing tensile properties amount to less than 30 wt. % of a wollastonite fiber, the fiber having a length of greater than 60 to 90 microns, a diameter greater than about 3 microns and an aspect ratio greater than about 3, the fiber having about 0.1 to 5 wt. % of an exterior coating comprising an organometallic interfacial modifier having a thickness of less than 1500 Å;
• and
• (b) the continuous polymer phase comprising a vinyl chloride polymer;
• wherein the composite has a fiber packing fraction of 40-95 vol. %, a heat deflection temperature of at least 60° C. (ASTM D648), a notched IZOD impact resistance of about 0.4 to 3.0 ft-lb-in−1 (ASTM D256), a COTE of about less than 2×10−5 in/in−1/° F. (ASTM 696), a tensile modulus (ASTM D638) of greater than 700,000 psi at 72° F., a flexural modulus (ASTM D790) of greater than 700,000 psi at 72° F., a flexural strength (ASTM D790) of greater than 2,500 psi at 72° F., a tensile strength (ASTM D638) of greater than 2,000 psi at 72° F. and the weight percentages are based on the composite.