Enhanced tensile and barrier properties of modified LLDPE with rubbery materials and graphene nanoplatelets for packaging application

Abstract

Linear low-density polyethylene (LLDPE) is widely used in industries. It possesses remarkable characteristics such as low density, easy to process, and recyclable. However, LLDPE-based products are known to be highly permeable to water and oxygen, thus limiting their application as packaging material. In this study, natural rubber (NR) and graphene nanoplatelets (GNP) were mixed with LLDPE to produce thermoplastic elastomer nanocomposites films as a novel, potential packaging material with the aid of liquid natural rubber (LNR) as compatibilizing agent. The formulation modification of GNP, NR, and LNR components influenced the mechanical and barrier properties of the resulting nanocomposites. The mixing methods, i.e., direct melt-mixing and masterbatch mixing (MB) were also investigated. Apparently, tensile test for samples prepared from MB mixing method yielded better results compared to samples from direct melt-mixing. Permeability tests of water vapor (WVP) and oxygen (OTR) demonstrated that LLDPE/GNP/NR/LNR nanocomposites films managed to reduce the permeability rate of WVP and OTR of pure LLDPE by 92.73% and 98.60%, respectively. The tortuous theory had been confirmed that the experimental data best fit the Nielsen model at aspect ratio of 20, 30 and 10, 20, 40, 200 for WVP and OTR, respectively.