Mechanical Properties of Injection-molded Natural Fiber-reinforced Polypropylene Composites: Formulation and Compounding Processes

Abstract

In this study, the effects of material optimization and compounding processes on the properties of natural fiber composites were studied. The thermal stabilities of sisal fiber and jute fiber were compared by thermogravimetric analysis. The influences of fiber content, coupling agent, fiber geometry, and fiber distribution on the properties were also researched. It was observed that sisal fiber had more thermal stability than jute fiber. Addition of coupling agent, long fiber length, and uniform fiber distribution led to higher performance composites. For the sisal fiber-reinforced polypropylene composites, the critical fiber length was 2.27 mm and the interfacial shear strength was 22.03 MPa with MAPP. The tensile strength of composites was also theoretically predicted based on Kelly-Tyson model.

Experimental investigation of the influence of the compounding process and the composite composition on the mechanical properties of a short flax fiber–reinforced polypropylene composite

“…However, the increase of the tensile strength with the addition of PP‐g‐MA is reported in different publications, although the Young's modulus remains as expected unaffected. The increase of the tensile strength is attributed to an enhanced adhesion between the matrix and the fibers . Bledzki et al reported that the notched impact strength is not significantly affected by PP‐g‐MA at flax fiber contents from 20 wt% above, which corresponds with the results obtained in this study.…”

“…So far, most scientific investigation of short flax fiber-reinforced PP composites focused on flax fiber or matrix modification using different chemical or physical pretreatments [1,7,[20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. These investigations show that treatment with maleic anhydride (MA) is one of the most effective methods and enhances in particular the tensile properties [1,7,[25][26][27][28][29][30][31][32][33][34][35]. Arbelaiz et al [25] showed that the modification of the polymer is more efficient than the fiber modification.…”

“…Arbelaiz et al [25] showed that the modification of the polymer is more efficient than the fiber modification. Fewer studies deal with the influence of the processing and mixing conditions on the mechanical properties of short natural fiber-reinforced polymer composites and in particular of short flax fiber-reinforced PP composites, even though these steps are crucial to retain a desired fiber length and, thus, to assure decent mechanical properties [2,7,27,[34][35][36][37][38][39]. Barkoula et al [27] and Bos et al [35] compared the flax fiber length after mixing with an extruder and a kneader.…”

Fiber dispersion during compounding/injection molding of PP/kenaf composites: Flammability and mechanical properties

“…Critical fiber length (l c ) of kenaf fiber in the PP matrix was estimated using the well-known Kelly and Tyson equation [32].…”

Studies on Okra Bast Fibre-Reinforced Phenol Formaldehyde Resin Composites

“…A number of studies have been reported on thermoset-plastics-natural fibre composites. Injection and extrusion moulding processes for fabrication of short fibre/thermoplastic composites are proficient and economic (Sun et al 2010;Paulo et al 2007). In extrusion moulding process, fibres are well distributed into a matrix which is most desirable for enhanced composite properties.…”