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Materials Advances
Fig. 4 Yellow mustard stain test. From top to bottom were uncoated MP trays, CNF/CMC coated MP trays, and formulated CNF coated trays. From left to right there were trays before testing, during testing, and after testing.
Table5 Young’s modulus, ultimate tensile strength, and strain at failure CNF-based dry sheets with different formulations. Data of 100CNF/10CMC are reprinted with permission from Zhang, J.; Youngblood, J. P. Cellulose Nanofibril (CNF)-Coated PFAS-Free, Grease-Resistant All-Bio-Based Molded Pulp Containers for Food Packaging. ACS Appl. Polym. Mater. , 2023, 5 (7), 5696–5706. Copyright 2024 American Chemical Society
Sample
Young’s modulus [GPa]
UTS [MPa]
Strain at failure [%]
10CNF/1CMC
9.36 0.57 5.14 0.13 5.25 0.21 5.84 0.27
110.57 7.30 100.48 2.78 107.35 2.27 136.31 5.82
1.80 0.08 2.97 0.39 3.13 0.22 3.54 0.42
100CNF/10CMC/1.5PAE
100CNF/10CMC/1.5PAE/3Cloisite-Na + 100CNF/10CMC/1.5PAE/3Cloisite-Na + /10PVA
Table6 Young’s modulus, ultimate tensile strength, and strain at failure for uncoated MP trays, CNF/CMC coated MP tray, and Formulated CNF coated trays. Data of uncoated MP trays and CNF/CMC coated MP trays are reprinted with permission from Zhang, J.; Youngblood, J. P. Cellulose Nanofibril (CNF)-Coated PFAS-Free, Grease-Resistant All-Bio-Based Molded Pulp Containers for Food Packaging. ACS Appl. Polym. Mater. , 2023, 5 (7), 5696–5706. Copyright 2024 American Chemical Society
Sample
Young’s modulus [GPa]
UTS [MPa]
Strain at failure [%]
Uncoated MP trays
0.23 0.02 1.22 0.10 0.62 0.05
5.82 0.23 16.34 0.42 15.31 0.53
1.70 0.14 1.77 0.05 3.84 0.03
10CNF/1CMC coated MP trays Formulated CNF coated MP trays
Forti et al. 50 also reported that increase in Young’s modulus and UTS was observed after adding 10 wt% PVA to CNF, however, the degree of enhancement was much higher, with a 63% increase in Young’s modulus and 35% increase in UTS. One Hypothesis that might be able to explain this discrepancy is the difference in processing methods. In the study by Forti et al. , 50 solvent casting was utilized to make CNF/PVA sheets. In this study, hot-press has been used. We assume that solvent casting might have resulted in a higher density of CNF/PVA than the hot-press method, leading to more interaction between
the PAE-crosslinked CNF went through a small period of plastic deformation before the fracture, resulting in an increase in strain at break. After the addition of Cloisite-Na + nano-clay, the increase in Young’s modulus was not significant, while the increase in UTS was significant ( a = 0.05), which could be explained the rein- forcement effect by the nano-clay addition. However, after the addition of PVA, significant increases in Young’s modulus and UTS were observed, which could be due to the intermolecu- lar hydrogen bonds formed between the PVA and the CNF.
2842 | Mater. Adv. , 2025, 6 , 2833–2844
© 2025 The Author(s). Published by the Royal Society of Chemistry
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