| abstract |
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. |