A pre-mold study of alkaline-silane treated EFB-PP composites based on thermal and rheological analysis

Rheological and thermal properties are important parameters to understand the role of the numerous variables involved in manufacturing and to achieve a high-quality final product. The composites were prepared by compounding polypropylene (PP) with treated (alkaline and silane) oil-palm empty fruit bunch (EFB) fiber using a twin screw extruder. Generally, regardless of fiber loading, the thermal stability of EFBPP composites was increased after using alkaline and silane-treated EFB fibers as reinforcement. DSC analysis shows that there is a change in the melting temperature (T-m) and the degree of crystallinity (X-c) values of the EFB composites. The melt flow rate (MFR) of the composites decreased while viscosity increased with an increase in fiber loading. Rheological analysis reveals the composites to have a viscoelastic solid behavior where storage modulus (G') is greater than loss modulus (G"). The composites exhibit predominantly viscous behaviour (G" > G') at lower frequencies, whereas at higher frequencies the composites exhibit elastic behavior (G' > G"). The decrement of complex viscosity (?*) with an increasing angular frequency (?) shows the materials exhibit shear thinning behavior. The composites also show the ability for regeneration when analyzed using time-dependent behavior.