Abstract: High-barrier polyamide 11 /ethylene-vinyl alcohol (PA11/EVOH) copolymer composites were prepared via in situ crosslinking induced by dicumyl peroxide (DCP).The effect of dosage of DCP on the gel content，mechanical property, barrier property and morphology was investigated.It showed that the impact strength, tensile strength and gel content initially increased and then reduced with increasing loading of the DCP. FT-IR analysis indicated that the ester groups were formed from the reaction betwecn carboxyl end groups in polyamidcl l and hydroxyl groups in FVOH. DSC showed that the glass transition temperature(Tg) decreased with increasing DCP content. SFM observation revealed that the DCP loading had a great influence on the morphology of FVOH within PA11 matrix. The discontinuous mutual crossover laminar structure of FVOH was developed when DCP loading was 1 .5，in which the mechanical property and barrier property were improved prodigiously.

Key words: polyamidc 11;ethylene-vinyl alcohol copolymer, dicumyl peroxide, in situ crosslinliing, barrier property