Filled composites comprising glass and polyester fibers

摘要

Polyurethane composites having improved mechanical strength and linear coefficient of thermal expansion (LCTE) and methods of manufacturing are described herein. The composites can include (a) a polyurethane formed by the reaction of (i) one or more isocyanates selected from the group consisting of diisocyanates, polyisocyanates, and mixtures thereof, and (ii) one or more polyols; (b) a filler in an amount of from greater than 50% to 90% by weight, based on the total weight of the polyurethane composite, (c) from 0.25% to 10% by weight, based on the total weight of the composite, of glass fibers; and (d) from 0.025% to 5% by weight, based on the total weight of the composite, of polyester fibers. The polyester fibers can have an average aspect ratio of length to diameter of from 5:1 to 600:1. The LCTE (−40° C. to 70° C.) of the polyurethane composite can be 2.2×10-5/° C. or less.