A composite structural material is prepared by admixing (1) sulfur plasticized by reaction with dicyclopentadiene, or dicyclopentadiene and styrene, (2) asbestos fibers wetted with dipentene, and (3) silica flour, maintaining the mixture at about 120 deg to 150 deg c for about 0.5 to 5 min and casting the resulting product under a pressure of about 500 to 1,500 psi. Additional strength is obtained by curing at elevated temperature prior to casting. Thus, 53 pct of powdered elemental sulfur was reacted with 5 pct of dicyclopentadiene at 140 deg c for 1 h. Eight pct of asbestos was wetted by refluxing with 1 pct of dipentene at 140 deg c. These materials plus 33 pct of silica flour (325 mesh) were mixed together for 2 min at 140 deg c. The mixture then was cast under 500 psi pressure into a 1 x 2 x 5 in bar and the pressure maintained for 0.5 H. It was then cooled to room temperature, and the rupture modulus of the product was found to be 2,515 psi. A similar experiment in which the pressure was 1,300 psi gave a product with a rupture modulus of 3,240 psi.
U.S. Pat. 4,022,626, May 10, 1977; Chem. Abstr. Not Found