disclosed are materials and compositions effective for the selective removal of gaseous aldehydes from tobacco smoke . the materials and compositions comprise tobacco smoke filters comprising a fibrous material or fibers of a polymeric material containing covalently - bonded acetoacetoxy residues . the fibrous material or fibers are capable of reacting with and removing aldehydes present in tobacco smoke . also disclosed are processes for the preparation of fibrous materials and fibers of a polymeric material containing covalently - bonded acetoacetoxy residues and methods for the removal of a gaseous aldehyde from tobacco smoke by contacting tobacco smoke with the aforesaid fibrous materials or fibers containing covalently - bonded acetoacetoxy residues .