Silver nanoparticles were deposited on the surface of the external polyamide 6 (PA6) layer of a multilayer film, by spraying and ultrasound-assisted methods. The effect of silver nanoparticles content and deposition method on the mechanical and optical properties of the multilayered films as well as the efficiency of silver ion release and their fungicidal characteristics were evaluated. Itaconic (IA) and Maleic anhydride (MA) were used as adhesion promoter agents for preventing the agglomeration of the silver nanoparticles and for improving the adhesion to the PA6 polymer surface. With IA, a homogeneous distribution of silver nanoparticles on the PA6 surface was achieved. The silver ion release and biocide effect of the multilayered films was found to be dependent on the anhydride type and on the deposition method used. The multilayer films with a layer of PA6-silver nanocomposite demonstrated good fungicidal activity, specifically against fungus Aspergillius niger. The observed results could be applied in the design of industrial films for packaging.

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Blends of linear low‐density polyethylene (LLDPE) and linear low‐density polyethylene grafted maleic anhydride (LLDPE‐gMA) were prepared by melt mixing and then coextruded as external layers, with a central layer of polyamide (PA) on three‐layer coextruded flat films. Blends with contents of 0% to 55 wt% of maleated LLDPE, on the external layers, were analyzed. The T‐peel strength and oxygen and water vapor transmission rate of the films were measured. The surfaces of the peeled films were characterized using attenuated total reflection infrared spectroscopy (FTIR‐ATR) and scanning electron microscopy (SEM). The observed increase in T‐peel strength of the films with 10% and higher levels of maleated LLDPE in the blend suggests good interfacial adhesion between layers. This sharp increase in peel strength appears to be associated, besides interdiffusion, with specific interactions between polymers, as the bond formation between maleic anhydride and the polyamide end groups by in situ block copolymer formation across the interface. No significant modifications in oxygen barrier properties of the films were observed; however, the use of higher contents of LLDPEgMA, even though it increases the adhesion performance, also increases the water vapor transmission rate by a reduction in the degree of crystallinity.

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Blends of linear low‐density polyethylene (LLDPE) and linear low‐density polyethylene–grafted maleic anhydride (LLDPE‐gMA) were used to promote the adhesion to polyamide 6 (PA) in a three‐layer coextruded film without using an additional adhesive or tie layer. The effect of bonding time and molecular weight (MW) of different maleated polyethylenes on the peel strength of the joints was analyzed. Direct evidence of a copolymer formed in‐situ at the interfaces is also considered. The peel strength of fusion bonded layers of LLDPE/LLDPE‐gMA blends with PA strongly depends on bonding time and molecular weight of the maleated polymer. Tensile properties of three‐layer films, made up of PA as the central layer and LLDPE/LLDPE‐gMA blends as the two external layers, are improved with increases in the maleic anhydride (MA) content in the blend. The in‐situ formation of a copolymer between the MA in the blend and the terminal amine groups of the PA was confirmed by the Molau test, infrared (IR) spectroscopy, and thermal analysis (DSC).