Improving tensile strength and impact toughness of plasticized poly(lactic acid) biocomposites by incorporating nanofibrillated cellulose

Abstract

Poly(lactic acid) (PLA) biocomposites are usually plasticized to overcome the problem of poor ductility, which decreases the valuable tensile strength. In this study, novel nanofibrillated cellulose (NFC) was extracted to enhance the acetyl tributyl citrate (ATBC) plasticized PLA biocomposites. Interestingly, NFC not only exhibited an excellent strengthening effect but also showed a further toughening effect in the biocomposites. When 4 wt% NFC was added, the tensile strength, elongation at break, and impact strength of the biocomposites with 15 wt% ATBC and 20 wt% ATBC reached 52.6 MPa, 28.4%, 34.9 J/m and 35.8 MPa, 300.1%, 40 J/m, respectively. This is at least 1.1 folds higher in strength and 2.3 folds higher in impact toughness than the biocomposites without NFC. Glass transition and melting temperature slightly increased with NFC addition. More importantly, the mechanism of the strengthening and toughening effect was definitely elucidated, and the comprehensive performance of the application was evaluated. The findings of the study provide significant guidance for PLA application, such as in food packaging, medical engineering materials, and household products.

Poly(lactic acid)/Plasticizer/Nano-Silica Ternary Systems: Properties Evolution and Effects on Degradation Rate

“…Samples with higher silica content showed the lowest impact toughness: this finding corroborates the effect of silica on plasticizer distribution, as suggested by thermal analysis and discussed in Section 3.2 . Low molecular weight plasticizers at high concentration are, in fact, often detrimental to impact resistance [ 36 ]. The evolution of impact toughness with aging time correlates with the proposed hypothesis of the structural evolution of materials: while toughness values show only slight fluctuations over time, within experimental error, from 12 weeks of aging some materials (S3_COOH and S5_COOH) begin to become too brittle to be tested (the load level during fracture was below the automatic trigger limit of the testing machine employed).…”

Thermal and mechanical properties of biocomposites in polylactic acid and food flour waste

“…Poly(lactic acid) (PLA) is a compostable aliphatic thermoplastic polyester produced by the polymerization of lactic acid, in turn, obtained from the fermentation of carbohydrates such as corn starch, sugar beet or sugar cane [12][13][14][15][16].Unfortunately, the potential employment prospects due to these peculiarities are still limited by some critical issuessuch as brittleness, low stiffness and thermal stability, very slow crystallization kinetics, poor melt strength often alleviated by adding speci c additives such as plasticizers, chain extenders, tougheners, and so on. [17][18][19].…”

Biodegradable and Biobased Mulch Films: Highly Stretchable PLA Composites with Different Industrial Vegetable Waste

“…This is important not only to build knowledge but also to establish a stream of vegetable waste recovery from agro-food industry for their incorporation in the production chain of new value-added products such as mulch films. In the past, cellulose extracted from biomass was used in plasticized PLA composites as reinforcing agents. − Here, we use the entire biomass in order to obtain not only a reinforcement effect but also a significant reduction in the price of the final materials, an incorporation of micro and macronutrients, and possibly, an improvement in PLA biodegradability in soil.…”