Biodegradable multilayer barrier films based on alginate/polyethyleneimine and biaxially oriented poly(lactic acid)

► Biodegradable multilayer films were prepared based on alginate and BOPLA. ► The oxygen barrier of the ALG/PEI coated BOPLA film was significantly improved. ► WVP, tensile properties and optical clarity were also studied. ► A possible barrier mechanism was proposed.