Characteristics of cellulose fibers from Opuntia ficus indica cladodes and its use as reinforcement for PET based composites

With the aim of valorizing the unexplored Moroccan resources, Opuntia ficus indica (OFI) cladodes were proposed as a renewable source for the production of cellulose. In this work, cellulose microfibers were extracted from OFI cladodes using one of the most suitable methods for the extraction of cellulose based on the alkaline delignification. The morphological (SEM), thermal (TGA/DTG), and structural (XRD, FTIR, and C-13 NMR) analysis of the isolated cellulose has been identified. Afterward, the reinforcing capability of cellulose fibers was examined using polyethylene terephthalate (PET) as a matrix by combining extrusion and compression molding processes. The effects of fibers loading on physical properties of the composites, such as tensile strength and Young's Modulus before and after water absorption, were studied. The stability of the optimal composite was also examined based on the dependence of rheological parameters (G' and G) with strain and time. Composites containing 15 wt% of fibers exhibited the best mechanical properties in dry and wet cases, reaching 88% increase from neat PET in Young's modulus and 36% increase in the tensile strength. However, excellent structural stability of the optimal composite was found with a predominant elastic behavior resulting from the good interface adhesion between cellulose fibers and PET matrix. The present work showed new routes for the valorization of OFI cladodes in the development of composite materials.

Automated summary

This study extracted cellulose microfibers from OFI cladodes and examined their reinforcement capability in PET matrix composite materials. The effects of fiber loading on physical properties of the composites were studied, with the 15% fiber loading composite showing the best mechanical properties in dry and wet conditions.