INTRODUCTION Synthetic fibers are advantageous in mechanical,thermal,and chemical properties and have gained applications in textile apparels,protective clothing,and engineering composite.However,most commodity synthetic fibers are hydrophobic,chemically inert,and uncomfortable to wear when used as clothing materials.Functional modifications of synthetic fibers to overcome the drawback properties have been the efforts of many fiber and polymer researchers for decades.Chemical modifications of polymers are one of the major approaches in functionalizing polymers and fibers in order to achieve durable and permanent novel properties.But,due to the differences in chemical structures and manufacturing processes,there are several methods to implement the chemical modifications of synthetic fibers,including copolymerization during synthesis,graft copolymerization during processing,and graft polymerization on surfaces of fibers.Chemistries and properties of all three processes in producing refreshable biocidal synthetic fibers will be presented here.