Synthesis and Property of Silicone Polymer from Chrysotile Asbestos by Acid-Leaching and Silylation

The porous, disordered, and fibrous silica derived from serpentine slag containing chrysotile asbestos by selective acid-leaching was converted to a silicone polymer through the silylation reaction of the silanol residue with chlorodimethylvinylsilane (DMVSCl). The polymer silylated with 1.2 equiv. of DMVSCl to the silica showed a 93% degree of silylation, which was fully soluble in various organic solvents. The 29Si-NMR measurement indicated that the obtained polymers have Q 4-, Q 3-, and M-type siloxane units.