The polyurethane elastomers with high mechanical strength and excellent self-healing properties were synthesized by traditional prepolymer method by introducing disulfide crosslinking agent to balance contradictions between mechanical properties and self-healing properties of self-healing materials. FT-IR was used to characterize the chemical structure. The hardness were measured by Shore hardness tester. The universal testing machine was used to test the self-healing efficiency at different conditions. The healing process were recorded by three-dimensional video microscope and photographing. And the thermal properties of the samples were characterized by a thermogravimetric analyzer. The results show that the disulfide structure is successfully introduced into the polyurethane elastomer, and most of Shore hardness of elastomer can reach more than 50 HA. Increasing temperature and prolonging time can improve self-healing efficiency of the elastomer. After 24 h of self-healing, the self-healing efficiency increases from 31.3% at 25 ℃ to 99.5% at 80 ℃. And at 80 ℃, the self-healing efficiency increased from 48.4% in 2 h to 99.5% in 24 h. The increase of the content of disulfide cross-linking agent is also beneficial to self-healing, and the healing efficiency of the elastomer has increased from 54.5% of PUSS-3 to 99.5% of PUSS-6. Thermogravimetric analysis shows that the thermal stability of the elastomer decreases slightly with the increase of disulfide content, but the 5% thermal weight loss temperature of all elastomers is higher than 265.0 ℃.
LI Qianlong①;WANG Zihao①;CHEN Kang①;JIAN Xiaoxia②;TANG Kaiyue②;ZHOU Weiliang②;XIAO Leqin②.
Preparation and Performances of Self-Healing Polyurethane Elastomers with High Strength. Explosive Materials. 2021, 50(6): 1-7 https://doi.org/10.3969/j.issn.1001-8352.2021.06.001