Plastic/fiber composite using recycled polypropylene and fibers from Sorghum halepense L.

Abstract

Leaf and stem fibers of Sorghum halepense L. (SH) were investigated as fillers for recycled polypropylene (RPP) at 10, 20, and 30 wt%. The effects of SH in RPP on the thermal and mechanical properties of composites were investigated by tensile and bending tests, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). It was found that mechanical properties of the RPP composites decreased but their elasticity modulus increased. The addition of SH fibers to the polymer matrix changed the thermal properties of RPP. A slight decrease in DSC crystallinity was observed with the addition of 10% SH leaf and stem fiber to the polymer matrix and then the percentages of crystallinity increased with the addition of 20% and 30% SH leaf and stem fiber. The SEM images showed that the SH fibers mixed well with the polymer matrix without agglomeration, and the fracture sections of the composites were less rough than that of the RPP by itself.

Utilization of flours from hemp stalks as reinforcement in polypropylene matrix

“…The TS values were reduced with increasing concentration of HS in the polypropylene matrix. It is thought that as the increased concentration of HS in the polypropylene matrix increases the interfacial area, the weakening of interfacial bonding between hydrophilic filler and hydrophobic polymer matrix decreases the TS (Yang et al 2004;Maziero et al 2019;Eroğlu et al 2023;Kilic et al 2023). Similar strength reduction by lignocellulosic filler addition due to the worsening interfacial bond between the polymer matrix and the filler was also reported by others (Bledzki and Faruk 2003;Yang et al 2007;Narlıoğlu et al 2018;Çavuş 2020;Çavuş and Mengeloğlu 2020;Başboğa et al 2022;Kilic et al 2023).…”