Properties and characterization of degradable low density polyethylene/rice bran composite films

Abstract

This research work aimed to study the mechanical, morphological, thermal, physical and biodegradability properties of low density polyethylene (LDPE)/rice bran (RB) films. LDPE/RB films were prepared using 0-5 wt% RB, glycerol as plasticizer, polyethylene-grafted-maleic anhydride (PEMAH) and Ultra-PlastTM TP10 (TP10) as compatibilizer by twin screw extrusion followed by blown film machine. It was found that the presence of 5 wt% RB contents had an adverse effect on the tensile strength of LDPE/RB films while the incorporation of PEMAH, TP10 and glycerol has increased the tensile strength of LDPE/RB films. The scanning electron microscope (SEM) micrographs showed that RB particles were clearly seen on the surface of all LDPE/RB films while addition of glycerol, PEMAH and TP10 in the films increased the distribution and dispersion phase of RB in LDPE matrix. Differential scanning calorimetry (DSC) results showed that degree of crystallinity (Xc) and melting enthalpy (?Hm) of the films have increased with the presence of RB content while melting temperature (Tm) and crystallization temperature (Tc) had showed no significant changes for all formulations. The reduction of Xc and ?Hm was observed upon addition of compatibilizers and plasticizer. Thermogravimetry analysis (TGA) analysis showed that the thermal degradation property slightly increased with the incorporation of RB but the reduction was observed with incorporation of PEMAH, TP10 and glycerol in LDPE/RB films. The incorporation of RB in LDPE has influenced the rate of water absorption and it was significantly increased with the addition of glycerol in LDPE/RB films. The addition of RB in LDPE/RB films has increased their biodegradabilities due to the attack of microorganism in soil while the incorporation of TP10, PEMAH and glycerol in LDPE/RB films also gave significant effects to the rate of biodegradation. The overall results showed that the incorporation of PEMAH and glycerol in LDPE/RB films performed better properties especially their mechanical properties.