Enzyme‐treated Tunisian Alfa fibers reinforced polylactic acid composites: An investigation in morphological, thermal, mechanical, and water resistance properties

Abstract

The present work is a comparative study of the impact of different Alfa fiber modifications on fiber properties, as well as on polylactic acid (PLA) composites behaviors. A specific process that combines successively mechanical, chemical, and enzymatic treatments (xylanase and pectinase) was employed to optimize the performances of Alfa fibers. The treatments reduced the levels of lignin, hemicellulose, and pectin in the fibers. This reduction was associated with a rise of defibrillation degree, an increase of cellulose content and an enhancement of thermal stability, as shown with SEM observations, biochemical composition determination, FTIR measurements and thermo‐gravimetric analyzer results. Bio‐composites were fabricated using a twin‐screw extruder and an injection‐molding machine with a fiber load of 20%. Tensile, flexural and water absorption tests revealed an improvement of mechanical strengths and water resistance for the treated fibers composites, with the enzyme treatment being the most efficient. SEM analysis showed a better impregnation and distribution of enzyme treated fibers within the matrix. An improvement of the thermal properties of composites filled with Alfa treated fibers was noticed when compared with untreated fibers composites. The data indicated that the technology of enzymes can be used as a powerful and eco‐friendly approach to treat natural fibers and to increase their potential of reinforcement.

The Water Absorption and Thermal Properties of Green Pterocarpus Angolensis ( Mukwa )-Polylactide Composites

“…The introduction of mukwa wood fibers into PLA increased the water absorption of PLA. Thus in agreement with the observation reported on Alfa fiber-PLA composites (Werchefani, Lacoste and Elloumi, et al 2020b). The water absorption increased with prolonged immersion, with the maximum values of 5.48, 3.51, 3.77, 3.37, and 0.61% recorded on day 28 for the untreated, alkali, laccase, alkali-laccase, and PLA, respectively.…”

“…The water absorption behavior and moisture retention of NFRPCs influences and deteriorates their functional properties and lifespan (Werchefani, Lacoste and Elloumi, et al 2020b). The relation between the water absorption of PLA, untreated, and treated mukwa/PLA composites, and the immersion duration is shown in Figure 2.…”

Alfa fibers for Cereplast bio-composites reinforcement: Effects of chemical and biological treatments on the mechanical properties

“…The strategy of alkaline treatment is outlined in an anterior publication. 23 Enzymatic treatment. Th procedure of enzymatic treatment with xylanase is the same mentioned in our previous work on PLA composites reinforced with Alfa fibers.…”

Investigation and prediction of mechanical properties of hot water treated jute/poly(lactic acid) composite laminates using response surface methodology and genetic algorithm

“…[ 8 ] Up to now, the most popular agricultural‐based polymer is polylactic acid (PLA), a biodegradable polymer produced from the fermentation of sugar. [ 9–11 ]…”

“…[8] Up to now, the most popular agricultural-based polymer is polylactic acid (PLA), a biodegradable polymer produced from the fermentation of sugar. [9][10][11] The polynomial models established through RSM are a technique based on the experimental design and regression analysis methods. [12] Heidari et al [13] minimized the warpage and shrinkage of three polylactic acid (PLA) based bone screws using an RSM technique.…”