A composite fiber comprising sorbent particles (at 50 wt %) in a polymeric matrix that comprises a polymer or blend of polymers including at least one thermoplastic polymer, the extrudates being produced by thermal-induced phase separation or diffusion-induced phase separation from a dope suspension of the thermoplastic polymer, an optional solvent and the sorbent particles. The polymer or blend of polymers is able to withstand exposure to temperatures at or above 220° C. without experiencing significant detrimental effects upon the sorbent capacity of the sorbent particles. The fiber exhibits an elongation at break of at least 5%.