AbstractConcern over environmental contamination and the need for industrially produced functional biopolymers motivates the utilization of reactive extrusion for functional grafting. Antioxidant nonmigratory active materials were synthesized through 1,3‐bis(4,5‐dihydro‐2‐oxazolyl)benzene ring opening polymerization with bio‐based poly(lactic acid) (PLA) and antioxidant nitrilotriacetic acid (NTA). Grafting was confirmed through the introduction of new alkyl stretching, disappearance of the characteristic 1,3‐bis(4,5‐dihydro‐2‐oxazolyl)benzene band, and emergence of new amide band on attenuated total reflectance Fourier transform infrared spectroscopy. X‐ray photoelectron spectroscopy (XPS) showed stepwise increases in atomic nitrogen percentage and shifts in proportion of CC:CO bonding, confirming grafting and surface orientation. Antioxidant samples exhibited significant increases in carboxylate density, ranging from 0.75 ± 0.04 to 3.11 ± 0.04 nmol/cm2. Functionalized films demonstrated significant antioxidant properties with Trolox(eq) ranging from 0.36 ± 0.02 to 0.89 ± 0.07 nmol/cm2 according to radical scavenging studies and delayed greater than 52% of ascorbic acid degradation. This work develops a rapid functionalization method for biopolymers and displays efficacy in producing sustainable nonmigratory active materials.