The present invention relates to synthetic methods for grafting hydrophilic chains onto polymers, particularly hydrophobic polymers such as poly(vinyl chloride) (PVC), poly(vinylidene fluoride) (PVDF), and chlorinated polypropylene (cPP). Resulting polymers include comb polymers which can have a microphase-separated structure of hydrophilic domains provided by the hydrophilic chains. Articles prepared from these comb polymers, particularly derived from PVDF, include membranes for water filtration in which the hydrophilic domains provide a pathway for water transport. PVC can be plasticized by grafting the PVC with hydrophilic chains. In addition, such articles, particularly articles having biomedical applications, can display anti-thrombogenic properties.