Barrier properties of nanocomposites from high-density polyethylene reinforced with natural attapulgite

Abstract

Attapulgite (ATT) has never been used as a barrier additive incorporated into polymers; instead, it has mostly been applied as a reinforcement or a nucleator. But ATT is very suitable as barrier additives in polymer materials because it can adsorb gas or water by virtue of its porous structure. In this study, ATT nanomaterials from natural minerals were purified and added to high-density polyethylene (HDPE) to prepare HDPE/ATT nanocomposites. The influence of a low content of ATT on the mechanical properties, crystallinity, morphology, water absorption, hydrophilicity, thermostability, and barrier properties of HDPE nanocomposites was analyzed. The results showed that adding a small amount of ATT could improve the mechanical properties, crystallinity, thermal stability, hydrophobicity, and barrier properties, but excessive amounts of it would reduce the mechanical and barrier properties. X-ray diffraction results showed that with increase in the ATT content, the peak did not significantly change and the nanocomposite material was mainly crystalline. According to the oxygen permeability test analysis, the oxygen barrier performance of the nanocomposite material was optimal when ATT was 0.4%. This great improvement in barrier performance might be ascribed to two reasons: (1) The presence of ATT extended the penetration path of molecules; (2) ATT itself had a porous structure, and molecules may be adsorbed and stored in it. Therefore, the addition of ATT led to good performance of HDPE nanocomposites, and this would lead to broad application prospects, which would be worthy of further study.