Co-MOF@MXene hybrids flame retardants for enhancing the fire safety of thermoplastic polyurethanes

• Published in: Polymer degradation and stability Vol. 204; p. 110119
• Main Authors: Shi, Congling, Wan, Mei, Hou, Zhengbo, Qian, Xiaodong, Che, Honglei, Qin, Yueping, Jing, Jingyun, Li, Jian, Ren, Fei, Yu, Bin, Hong, Ningning
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2022
• Subjects: calorimeters; Co-MOF; degradation; Fire safety; flame retardants; heat; MXene; nanocomposites; polyurethanes; smoke; thermogravimetry; Thermoplastic polyurethanes; thermoplastics; Co-MOF; Thermoplastic polyurethanes; MXene; Fire safety
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/j.polymdegradstab.2022.110119

•MOFs was assembled with two-dimensional MXene nanosheets to form a novel flame retardant hybrids (Co-MOF@MXene) by solvothermal method.•The mechanism of Co-MOF@MXene hybrids is based on the interaction of end-group motifs on MXene and the unsaturated sites of metal ions on MOF.•TPU/Co-MOF@MXene composites showed excellent fire safety properties.•The excellent fire safety properties of TPU/Co-MOF@MXene composites are due to the physical barrier, catalytical carbonization, and gas-phase flame retardant of Co-MOF@MXene hybrids. Thermoplastic polyurethane (TPU) is the most used polyurethane, but its highly flammable characteristic restricts its extensive use. In this work, Co-MOF@MXene hybrids flame retardants were synthesized and incorporated into TPU. The flame-retardant characteristics of TPU composites were investigated by cone calorimeter test and thermogravimetric analyzer. Compared with TPU, the peak heat release rate and total heat release rate of TPU/Co-MOF@MXene composites were reduced by 28.3% and 14.5%, respectively; and the smoke production rate and total smoke production of the composites with only 2 wt% Co-MOF@MXene hybrids were also reduced by 58.8% and 47.5%, respectively. Furthermore, the char residues of TPU/Co-MOF@MXene composites were about 2 times that of pure TPU. Systematical characterizations were then carried out to investigate the flame retardant mechanism of Co-MOF@MXene hybrids, highlighting the barrier effects of MXene combined with the catalytic effect of Ti and Co. The hybrids flame retardants greatly benefit the further development of TPU nanocomposites.