Self-cleaning and hydrophobic pineapple peel fibre based biocomposite

Abstract

Biocomposite has been widely used as plastics replacement for its biodegradability. However, the water absorptivity defeats its purpose as food packaging. The water absorption analysis for pineapple peel fiber (PAPF) was done according to ASTM D570-98 and it has been proven that the water content increases to 7.2% with the 50% content of PAPF in the bio-composite (50% PAPF). For that matter, hydrophobic coating was synthesized and applied on PAPF based bio-composite. The bio-composite was produced using Low Density Polyethylene (LDPE), pineapple peel fibre (PAPF), Linear LDPE grafted maleic anhydride (LLDPE-g-MA) as compatibilizer and Refined, Bleached Deodorized Olein (RBDOL) as plasticizer. The coating was synthesized by using polydimethylsiloxane (PDMS) and decamethylcyclopentasiloxane as hydrophobic component, silica nano-particles as nanostructured particles and non-organic solvent and non-ionic surfactant p-octyl polyethylene glycol phenyl ether as surfactant. The emulsion was homogenized and after that sprayed onto the surface of PAPF bio-composite and dried in the oven at 50-60C for 24 hours. Through the 100μm magnification using field emission scanning electron microscope (FESEM), the hydrophobic coating was proven to conform the Cassie-Baxter hydrophobic property. C-O bond from the PAPF disintegrates after the production of bio-composite from the Attenuated Total Reflectance Fourier Transform Infrared (ATR FTIR) spectrometry transmittance. The application of the coating onto the surface of PAPF bio-composite gave the surface hydrophobic property where the contact angle changes from 82.27±2.66 which is hydrophilic to 122.63±2.17 which is hydrophobic. The bio-composite with the highest PAPF content will also exhibit self-cleaning ability which makes it suitable for the usage of hydrophobic food packaging material.