Disclosed herein is a composition having a plurality of particles of a filler material and crosslinking units having the formula —(SiR—CH2—CH2—CH2)—. The silicon atom in the crosslinking unit is directly or indirectly bound to the filler material. Each R is alkyl, alkenyl, phenyl, methyl, ethyl, allyl, halogen, chloro, or bromo. Also disclosed herein is a filler material having the silicon atom of a silacyclobutane group is directly or indirectly bound thereto. Also disclosed herein is a method of crosslinking silacyclobutane groups bound to a plurality of particles of a filler material. The silicon atom of the silacyclobutane group is directly or indirectly bound to the filler material. Also disclosed herein is a composition including a plurality of fibers of a polymer having reactive oxygen atoms and siloxane groups. Coordination bonds are formed between the oxygen atoms and the silicon atoms of the siloxane groups of separate fibers.