Fracture Surface Morphology and Impact Strength of Cellulose/PLA Composites

Abstract

Polylactide (PLA)-based composite materials reinforced with ball-milled celluloses were manufactured by extrusion blending followed by injection molding. Their surface morphology from impact fracture were imaged with scanning electron microscopy (SEM) and investigated by calculating their fractal dimensions. Then, linear regression was used to explore the relationship between fractal dimension and impact strength of the resultant cellulose/PLA composite materials. The results show that filling the ball-milled celluloses into PLA can improve the impact toughness of PLA by a minimum of 38%. It was demonstrated that the fracture pattern of the cellulose/PLA composite materials is different from that of pristine PLA. For the resultant composite materials, the fractal dimension of the impact fractured surfaces increased with increasing filling content and decreasing particle size of the ball-milled cellulose particles. There were highly positive correlations between fractal dimension of the fractured surfaces and impact strength of the cellulose/PLA composites. However, the linearity between fractal dimension and impact strength were different for the different methods, due to their different R-squared values. The approach presented in this work will help to understand the structure–property relationships of composite materials from a new perspective.

Green esterification: A new approach to improve thermal and mechanical properties of poly(lactic acid) composites reinforced by cellulose nanocrystals

“…This behavior was supported by a rough and irregular fractured surface in PLA‐b‐CNCs nanocomposites observed from SEM images (Figure ). Similar results were reported by Gao and Qiang who showed higher impact strength for PLA‐based nanocomposites with a rougher fractured surface.…”

“…However, nanocomposites with 1 and 3 wt % b‐CNCs exhibited rough and irregular surfaces, suggesting the ductile fracture mechanism in PLA‐1b‐CNCs and PLA‐3b‐CNCs nanocomposites. In general, the fractured surface can illustrate the impact resistance of the materials . The rough and irregular fractured surface in PLA‐b‐CNCs nanocomposites indicated more required work for impact fracture as compared with PLA‐CNCs nanocomposites.…”

“…In general, the fractured surface can illustrate the impact resistance of the materials. [31][32][33] The rough and irregular fractured surface in PLA-b-CNCs nanocomposites indicated more required work for impact fracture as compared with PLA-CNCs nanocomposites. It also suggested the higher impact resistance in PLA-b-CNCs nanocomposites than PLA-CNCs nanocomposites.…”

The effect of nanomodified epoxy on the tensile and flexural properties of Napier fiber reinforced composites

“…This was supported by the morphological study by Mohammadalipour et al, which revealed similar images for their neat epoxy composite. The river marking zones were also observed by H. Gao and T. Qiang through SEM analysis of a virgin PLA composite using a larger magnification, confirming that the unfilled composite exhibited a brittle fracture pattern.…”

Effect of empty fruit bunches microcrystalline cellulose (MCC) on the thermal, mechanical and morphological properties of biodegradable poly (lactic acid) (PLA) and polybutylene adipate terephthalate (PBAT) composites

“…Differential scanning calorimetry (DSC) Figure 4 displays the second heating DSC curves of pure PLA, pure PBAT and PLA/PBAT blends with varying PBAT contents. The second heating curves were chosen to remove previous thermal history and to make T g clearer and more obvious as stated by (Jiang et al 2006, Gao andQiang 2017). From the DSC curves in figure 4, T g of PBAT was absent due to T g of PBAT was reported at −37°C (Signori et al 2015) (Carbonell-Verdu et al 2018).…”