The aim of the present invention is a filament or fibre absorbing the odorous molecules, especially acid and/or basic gas(es), having a determined external surface whereof at least one portion of said surface comprises carboxylic groups –COOH and/or carboxylate groups –COO–complexed with metallic salts. Advantageously, said portion is constituted by a matrix originating from the reaction of a mixture comprising a polyester as well as a first copolymer of at least one olefin and alkyl (meth)acrylate and/or (meth)acrylate acid (A), and a second (co)polymer comprising oxiran groups –C2H3O (B), at least some of the (meth)acrylate functions of the copolymer (A) having been transformed into corresponding carboxylate and/or corresponding carboxylic functions.本發明之目標為吸收有氣味分子，尤其酸及/或鹼性氣體之絲或纖維，其具有確定之外表面，其中該表面之至少一部分包含羧基-COOH及/或與金屬鹽錯合之羧酸根基。有利地，該部分由以下基質構成，該基質源自包含聚酯以及至少一種烯烴及(甲基)丙烯酸烷基酯及/或(甲基)丙烯酸的第一共聚物(A)，及包含環氧乙烷基-C2H3O之第二(共)聚物(B)的混合物的反應，共聚物(A)之至少一些(甲基)丙烯酸酯官能基已轉換成相應羧酸根及/或相應羧酸官能基。
