Influence of Nano‐Sized Calcium Carbonate on Adhesion of HDPE/ Cross‐Linked High Density Polyethylene Multilayer Structures

Abstract

Novel composites of silane cross‐linked high‐density polyethylene (PEX) reinforced by nanosized calcium carbonate (NCC) were welded to high‐density polyethylene (HDPE) using lamination method. The effects of NCC content on interfacial interactions of the bilayer structures were studied through morphological, mechanical, and thermal observations. Scanning electron microscopy (SEM) micrographs indicated that transcrystalline layer could be generated by adding NCC up to 5 wt%, which improves crystallinity in the interfacial region; however, incorporation of 10 wt% NCCs restricted lamellar alignments and did not change interfacial crystallinity. Impact resistance synergy was also observed in multilayer structures containing transcrystalline layer. The results showed improvement of peel energy of neat PEX up to 50% by addition of 5 wt% NCCs which is attributed to transcrystallization and chain attraction on the nanofiller's surface. The adhesion of layers promoted generally by annealing because of increasing possibility of interfacial interactions via chain mobility.