Study On Preparation And Properties Of Biaxially Oriented Nylon 6/Polyketone Composite Film

Biaxially oriented nylon film(BOPA)is a kind of plastic packaging material with excellent properties,which is widely used in food packaging,medical packaging,daily chemical packaging,lithium battery packaging and other fields.However,the barrier performance of nylon(PA6)film cannot reach the level of high barrier materials.At the same time,it also has many problems such as poor dimensional stability,inability to resist ultraviolet aging,poor antibacterial performance,and poor linear tearing performance,which often make it suffer limit in daily applications.In this paper,functionalized biaxially oriented nylon 6/polyketone composite films were prepared via the simultaneous stretching process,and modified by polyketone(PK),graphene oxide(GO),cerium oxide(CeO₂),zinc-cerium loaded silica and poly-m-xylene adipamide(MXD6).Thereby the above-mentioned problems of the nylon film were improved.Meanwhile,the influence of stretch orientation on the structure and performance of nylon film was also discussed.Therefore,the work of this paper can provide new choices and new ideas for the application of nylon film in the field of green packaging,so as to ensure the quality and safety of packaging products.The main research contents and innovations of this paper are as follows:(1)In order to solve the defect of insufficient barrier performance of PA6 film,polyketone was introduced into the nylon matrix.The new type of high barrier biaxially oriented PA6/PK composite film was prepared by melt blending and simultaneous biaxial stretching process.The study found that the barrier properties,toughness and dimensional stability of the biaxially stretched PA6/PK composite film can be significantly improved by appropriate amount of PK.At the same time,the stretch orientation can significantly increase the crystallinity of the biaxially stretched PA6/PK composite film,and most of the PA6 crystals exist as the?crystal form.(2)In order to further improve the barrier properties of the biaxially stretched PA6/PK composite film,the component of GO was added in the film.The influence of GO and stretch orientation on the barrier properties of the composite film was discussed.The results show that GO can further improve the barrier properties of the biaxially stretched PA6/PK/GO film.What's more,the stretch orientation contribute to the inducing of film crystallization so as to improve the barrier properties of the composite film.At the same time,it is found that GO can promote the crystallization of PA6/PK composites.(3)In order to overcome the defect of nylon 6 film which was not resistant to ultraviolet aging,the component of cerium oxide was introduced into the PA6/PK blending,then a biaxially stretched PA6/PK/CeO₂ composite film was prepared by the process of simultaneous stretching.The results show that the surface-modified cerium oxide is uniformly dispersed in the PA6/PK composite system,and the addition of a small amount of cerium oxide can significantly improve the UV resistance of the composite film.At the same time,cerium oxide has a heterogeneous nucleation effect on the PA6/PK composite system.(4)In order to overcome the defect of nylon 6 film which has poor antibacterial performance,zinc-cerium loaded silica powder,which was prepared by sol-gel process,was doped into the biaxially oriented nylon6/polyketone composite film to improve its antibacterial properties.At the same time,the influence of preparation conditions on powder particle size and loading ion concentration on powder antibacterial performance was systematically studied,and the synergistic antibacterial effect of zinc and cerium antibacterial ions was explained.(5)In order to overcome the poor linear tearing performance of nylon6 film,the MXD6 component was introduced into the PA6/PK system,and the biaxial stretching PA/PK/MXD6 composite film with excellent linear tearing performance was prepared by melt blending and simultaneous biaxial stretching process.The effect of MXD6 on the linear tear performance and mechanical properties of the composite film was systematically studied.