Confine Clay in an Alternating Multi layered Structure through Injection Molding: A Simple and Efficient Route to Improve Barrier Performance of Polymeric Materials

Various methods haVe been devoted to trigger the formation of multilayered structure for wide range of applications. These methods are often complicated with low production efficiency or require complex equipment. Herein, we demonstrate a simple and efficient method for the fabrication of polymeric sheets, containing naultilayered structure with enhanced barrier property through high- speed :thinwall injection molding (HSIM). To achieve this, montmnrillonite (MMT) is added into PE firSt, then blended with PP to fabricate PE-MMT/PP ternary composites. It is demonstrated that alternating mtiltilayer structure could be obtained in the ternary composites because of low interfacial tension and good viscosity thatch between different polymer components. MMT is selectively dispersed in PE phase with partial exfoliated/partial intercalated microstructure. 2D-WAND analysis indicates that the clay tactoids in PE-MMT/PP exhibits an uniplanar-axial orientation with their surface parallel to the molded part surface; while the tadoids in binary PE-MMT composites with the same overall M.MT contents illustrate less orientation. The enhanced orientation of narioclay in PE-MMT/PP could :be attributed to the cOnfinement of alternating, multilayer structure, which prohibits the tumbling and rotation of Panoplatelets. Therefore, the oxygen barrier property of PE-MMT/PP is superior to that of PE-MMT because of increased gas permeation pathway. Comparing with the results obtained for PE based composites in literature, outstanding barrier property performance (45.7% and 58.2% improvement with LS and 2.5 wt % MMT content, respectively) is achieved in current study. Two issues are considered responsible for such improvement: enhanced MMT orientation caused by the confinement in layered structure, and higher local density of MMT in layered structure' induced denser assembly. Finally, enhancement in barrier property by confining impermeable filler into alternating multilayer structure through such simple and efficient method could provide a novel route toward high-performance packaging materials and other functional materials require layered structure.