Acrylonitrile copolymers containing guanidine oligomer: Synthesis and use for the preparation of nonleaching antimicrobial acrylic fibers

Nonleaching acrylic fibers with permanent antibacterial activity were prepared via a combination of copolymerization and a wet‐blend‐spinning method. Specifically, poly[acrylonitrile‐co‐modified poly(hexamethylene guanidine hydrochloride)] [poly(AN‐co‐M‐PHMG)] copolymers containing a covalently connected antibacterial guanidine oligomer were first synthesized via the precipitation copolymerization of acrylonitrile (AN) with a modified poly(hexamethylene guanidine hydrochloride) (M‐PHMG) macromonomer in water. Then, modified acrylic fibers were prepared from a mixture of the copolymer and commercial fiber‐grade AN terpolymer via a wet‐spinning process with dimethyl sulfoxide as the solvent. The influences of the reaction time, temperature, pH value of the medium, and amount of initiator on the copolymerization and the effect of the copolymer content on the mechanical properties and antibacterial activity of the modified acrylic fibers were investigated in detail. The results show that the M‐PHMG macromonomer exhibited a lower reactivity than AN. The poly(AN‐co‐M‐PHMG) copolymer with a PHMG content of 5.49% and an intrinsic viscosity of 11.2 dL/g could be synthesized under optimized conditions. With increasing copolymer content, the tensile strength of the modified acrylic fibers decreased slightly, and the antibacterial activity increased. The modified acrylic fibers with a copolymer content of 50% (i.e., a PHMG content of 2.75%) exhibited both good mechanical properties and excellent antibacterial activity. The additional antibacterial function would surely enlarge the applications of the fiber. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013