Mechanical, rheological, thermal and morphological properties of pistachio shell powder reinforced / linear low-density polyethylene/polyolefin elastomer biocomposites

Abstract

In the present study, 20 wt% ENGAGE (a polyolefin elastomer) is melt blended with 80 wt% linear low-density polyethylene (LLDPE) followed by composite preparation with pistachio shell powder (PSP) in various compositions (40 wt% to 70 wt%). The effect of variation of PSP content on mechanical properties is studied. The processability of composites is improved because of the unique processability of ENGAGE. Consequently, filler-containing capability of the LLDPE/ENGAGE (LE82) blend is also enhanced considerably due to extra space generated by amorphous ENGAGE. Again, blending of 20 wt% ENGAGE with 80 wt% LLDPE is helpful for maintaining mechanical properties of LLDPE/ENGAGE/PSP composite in useful range. The rheological study confirms that complex viscosity (η), storage modulus (G’) and loss modulus (G”) remain almost unchanged with the incorporation of a high quantity of PSP into the LE82 blend system for all the composites in the entire frequency range. From the rheological study, it is seen that the thermoplastic nature of the composites is maintained. Thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) show the structural integrity of LE82 blend-based composites revealing the thermal stability of the organic filler and consequently the composites. SEM also shows uniform dispersion of PSP into the LLDPE/ENGAGE blend matrix. Such biocomposite with 70 wt% biodegradable component and reliable mechanical properties is attractive for wide spread applications.