Processing and characterization of waste denim fiber reinforced polymer composites

Abstract

In this research, polymer matrix composites of denim fiber reinforcements with a view to recycling the wastes from garments industries are studied. Polypropylene matrix based composite structures were prepared by using waste denim fiber at different wt.% and for different fiber orientations. The mechanical, thermal, chemical and morphological properties of the composites were characterized. The results indicated that the flexural strength and the flexure modulus of the composites improved with increasing fiber percentage because even dispersion of fibers in the matrix can be possible for higher percentage of fibers and the huge amount of fibers are capable to withstand higher bending load. Better tensile properties were obtained at lower fiber content. Agglomeration of fibers, increase in fiber–fiber interaction and the increased void content all are responsible for the reduced tensile strength of the composites containing higher fiber percentage. Lower values of hardness at higher fiber fraction were obtained due to the presence of voids and porosity. The surface morphology of the fracture surfaces of the tensile specimens, examined by a field emission scanning electron microscope, revealed the poor interfacial bonding between fiber and matrix and as well as the presence of micro voids and blowholes in the fracture surface. The infrared spectra of pp-denim fiber composites were taken and the characteristic peaks were studied. The lower thermal stability of the newly developed composites was confirmed by thermo gravimetric analysis (TGA).