Submitted to: Polymers
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/20/2022
Publication Date: 5/25/2022
Citation: Jordan, J.H., Easson, M.W., Cheng, H.N., Condon, B.D. 2022. Application of lignin-containing cellulose nanofibers and cottonseed protein isolate for improved performance of paper. Polymers. 14(11), 2154. https://doi.org/10.3390/polym14112154.
Interpretive Summary: There is current interest in using biopolymers to replace petroleum-based additives because they are abundantly available, renewable, and sustainable. Cottonseed protein is a biopolymer that is used as an adhesive and as a strength modifier for paper products. The strength performance properties were improved for paper products when cottonseed protein was applied with formulations containing cellulose nanofibers and cellulose nanocrystals. Cellulose nanofibers and nanocrystals are high-value commodities that can be produced from low-value, underutilized agricultural renewable resources, such as cotton gin motes and cotton gin trash. However, the isolation of nanocellulose from these agricultural products requires costly chemical modifications, bleaching and processing. Lignin-containing cellulose nanofibers, on the other hand, can be prepared by simple mechanical means after only mild chemical treatment, and do not require an exhaustive chemical bleaching step. Therefore, it may be beneficial to utilize lignin-containing cellulose nanofibers as a performance additive in combination with cottonseed protein. This research characterized the performance use of lignin-containing cellulose nanofibers with varying lignin content as an additive with cottonseed protein isolate to increase the dry strength of paper products. Improved dry strength was observed with the composites containing greater amounts of lignin compared to those prepared with a lower lignin content, or compared to cottonseed protein alone.
Technical Abstract: There is current interest in replacing petroleum-based additives in consumer paper products with abundantly available, renewable and sustainable biopolymers such as lignin-containing cellulose nanofibers (LCNFs) and cottonseed protein. This research characterized the performance of cottonseed protein isolate with/without LCNFs to increase the dry strength of filter paper. Application of 10% protein solution with 2% LCNFs as an additive improved the elongation at break, tensile strength and modulus of treated paper products compared to the improved performance of cot-tonseed protein alone. Improvements in tensile modulus and tensile strength were greatest for samples containing larger amounts of lignin and greater degree of polymerization than for those with less lignin from the same biomass sources.