Four-Ingredient Blends of Poly(lactic acid) with Cottonseed Oil and Meal for Biocomposite Utilization

• Published in: Macromol 2024-10, Vol.4 (4), p.708-722
• Main Authors: He, Zhongqi, Cheng, Huai N., Ford, Catrina V., Nam, Sunghyun, Fortier, Chanel, Santiago Cintron, Michael, Olanya, Ocen Modesto, Uknalis, Joseph
• Format: Article
• Language: English
• ISSN: 2673-6209; 2673-6209
• DOI: 10.3390/macromol4040042

The development and characterization of agricultural byproduct-based biocomposites are an important part of green chemistry. In this work, four-ingredient blends were formulated with the melt blending method. The set of composites (named as CSO series) was made with poly(lactic acid) (PLA) as the major matrix, washed cottonseed meal (WCSM) as a filler, cottonseed oil (CSO) as a compatibilizer, and glycerol (GLY) as a plasticizer. The morphological analysis showed the homogenous dispersion of the cottonseed byproducts into the PLA matrix to some extent. The thermogravimetric analysis revealed that thermal stability was impacted by the ingredient’s addition. The functional group analysis of the sample and simulation by Fourier transform infrared spectra confirmed the chemical interactions of PLA with WCSM in the blend products. CSO was most likely subjected to physical blending into the products. The mechanical strengths of those composites were affected by the ratios of PLA-CSO. Generally, the tensile strengths were in the range of 0.74–2.1 MPa, which indicate its suitability for low-strength biodegradable plant container development. The blend products had a lower water absorption during the water soaking test. This work shows the feasibility of incorporating cottonseed WCSM and CSO into a PLA composite for sustainable agricultural applications.