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ARS Home » Plains Area » Lubbock, Texas » Cropping Systems Research Laboratory » Cotton Production and Processing Research » Research » Publications at this Location » Publication #390848
Research Project: Enhancing the Profitability and Sustainability of Upland Cotton, Cottonseed, and Agricultural Byproducts through Improvements in Pre-Ginning, Ginning, and Post-Ginning Processes

Location: Cotton Production and Processing Research

Title: Enhancing UV-shielding and mechanical properties of polylactic acid nanocomposites by adding lignin coated cellulose nanocrystals

Author
item SHOJAEIARANI, JAMILEH - Western New England University
item BAJWA, DILPREET - Montana State University
item RYAN, CECILY - Montana State University
item KANE, SETH - Montana State University
item Holt, Gregory

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/3/2022
Publication Date: 9/1/2022
Citation: Shojaeiarani, J., Bajwa, D., Ryan, C., Kane, S., Holt, G.A. 2022. Enhancing UV-shielding and mechanical properties of polylactic acid nanocomposites by adding lignin coated cellulose nanocrystals. Industrial Crops and Products. 183. Article 114904.

Interpretive Summary: As composite materials become more and more popular there is a need to improve performance characteristics. In this study, the focus was to increase protection of a traditional thermoplastic composite (a composite made from a mixture of plastic and organic material) from UV (ultra-violet light) degredation by adding microscopic lignin fillers. The test results showed that the UV protection of the thermoplastic composite was improved significantly with the addition of as little as 3% lignin fillers.

Technical Abstract: From a perspective of sustainable development, it is desired to develop biodegradable UV-resistant and mechanically robust materials. Lignin nanofillers (LNP) are renewable and commercially available nanofillers with promising UV-shielding characteristics. However, the addition of LNP can deteriorate the mechanical properties of lignin-based composites. On the other hand, cellulose nanocrystals containing lignin can serve as a UV-shielding and reinforcing nanofiller without sacrificing the mechanical properties of nanocomposites. In this work, the UV-shielding performance, mechanical properties, and biodegradability of PLA nanocomposites containing lignin-coated cellulose nanocrystals (LCNC) were compared to PLA nanocomposites reinforced with lignin nanofillers (LNP). PLA nanocomposites with different content of nanofillers (i.e., 3, and 5%) were prepared via a masterbatch approach followed by extrusion and injection molding. The morphologies of PLA nanocomposites studied by scanning electron microscopy, confirmed smooth fracture surfaces with micro sized LCNCs aggregates. However, rough fracture surfaces and uniform nanoparticle dispersion were observed in PLA nanocomposites reinforced by LNP. Results from UV–Vis characterization revealed a synergic effect of incorporating either LNP or LCNCs nanostructures in terms of UV light blocking ability. The addition of low content (3wt %) LCNCs into the PLA matrix, blocked the highest amount of UV radiation, 75.27% of UV-A and 45.81% of UV-B. Degradation tests of PLA and its nanocomposites showed that the maximum weight loss of PLA nanocomposites after being hydrolytically degraded for 30 days increased from 8% for PLA to 14% for PLA-5 wt.% LCNCs, and 16.7% for PLA-5%LNP. The study provides insights into PLA nanocomposite reinforced with LCNCs or LNP regarding UV protection, biodegradability, and mechanical properties.