Acetylation used for natural fiber/polymer composites

Abstract

Nonwoven unidirectional matted banana empty fruit bunch fiber (BBF)-reinforced polypropylene (PP) composites were successfully fabricated by compression molding method. The effect of fiber composition, mercerization of fiber as well as incorporation of acetylation as coupling agent on the properties of PP/BBF composites was studied. The results indicated that the BBFs acted as reinforcing fillers, increasing the mechanical properties (e.g. tensile strength, tensile modulus, and Charpy impact strength) of the composites. PP/BBF composites with acetylation after the alkali pretreatment showed better interfacial shear strength and mechanical properties compared to the alkali-treated and untreated fiber composites. Scanning electron microscopy studies carried out on fractured specimens indicated poor dispersion in the untreated fiber composites and improved adhesion and uniform dispersion in the treated composites. Thermogravimetric analysis/derivative thermogravimetric thermograms revealed an increase in the stability of acetylation-incorporated systems and differential scanning calorimetry results exhibited improved thermal stability as compared with neat PP. The heat deflection temperature and flammability also displayed improved thermal stability as compared with neat PP. The moisture absorption test showed that acetylation-treated banana matted composites exhibited less water absorption than both alkali-treated and untreated composites.