Effect of alkali surface treatment and compatibilizer agent on tensile and morphological properties of date palm fibers-based high density polyethylene biocomposites

The objective of the present study is to develop an environment friendly alternative material based on available and local bio-source from the wastes of Algerian date palm trees, date palm twigs fiber (DPF) was selected as an effective reinforcing material for high density polyethylene (HDPE) biocomposite. Two types of treatments have been used including sodium hydroxide (NaOH) treatment to obtain DPF1 followed by potassium permanganate (KMnO₄) treatment to obtain DPF2 for aim to improve fiber-matrix compatibility, HDPE biocomposite reinforced with different ratios of DPF1 and DPF2 varying from 10 to 30 wt% were elaborated, characterized, and compared to select the preferred treatment and percent of DPF which can be used with high properties. The results obtained indicates that the incorporating of 30 wt% of DPF2 in HDPE biocomposite led to an improve in the mechanical and morphological properties. In fact, the improvement in interfacial properties improve ultimate biocomposite performance, and thus qualified its use in different industrial application. The maleic anhydride grafted high-density polyethylene (HDPE-g-MA) was incorporated as a coupling agent to the reinforced biocomposite of 30 wt% DPF2/HDPE with two different loading (7 and 10 wt%), Also, the treatments were seen to enhance the tensile strength and elastic modulus. Additionally, the biocomposites observation by scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed more intimate contact between the fibers and HDEP matrix after surface modification. The results suggested that the successful sample with best characteristics which can be advised is 30 wt% DPF2/HDPE/10 wt% HDPE-g-MA, that offer their use in many applications particularly in the automotive industry.