Welcome to Chemistry and Industry of Forest Products,

Chemistry and Industry of Forest Products ›› 2024, Vol. 44 ›› Issue (2): 71-78.doi: 10.3969/j.issn.0253-2417.2024.02.010

Previous Articles     Next Articles

Preparation and Properties of Bio-based Schiff Base Self-repairing Polyurethane

Xu FAN1,2, Fuhao DONG1, He LIU1, Jianxin JIANG2, Zhanqian SONG1,*()   

  1. 1. Institute of Chemical Industry of Forest Products, CAF; Key Lab.of Biomass Energy and Material, Jiangsu Province; Key Lab.of Chemical Engineering of Forest Products, National Forestry and Grassland Administration; National Engineering Research Center of Low-Carbon Processing and Utilization of Forest Biomass; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing 210042, China
    2. College of Materials Science and Technology, Beijing Forestry University, Beijing 100083, China
  • Received:2023-02-21 Online:2024-04-28 Published:2024-04-23
  • Contact: Zhanqian SONG E-mail:songzq@hotmail.com

Abstract:

Dynamic covalent bonds were a type of chemical bond that can be broken and restored under specific conditions. Among them, Schiff base was a dynamic covalent bond formed by the condensation of aldehydes and amine compounds. A bio-based Schiff base compound(MV/S) was synthesized by the reaction between the amine group of 1, 8-p-menthanediamine(MD) with the aldehyde group of vanillin. A Schiff base compound(EV/S) without aliphatic ring was synthesized by replacing MD with ethylenediamine. Using MV/S and EV/S as chain extenders, the self-healing Schiff base polyurethane films(PU/SM and PU/SE) were prepared, At the sametime, the polyurethane without Schiff base(PU/BDO) prepared without MV/S and EV/S was used as a blank control to determine the effect of MD on the properties of self-healing polyurethane. Various analytical and testing methods were employed to study the structure, mechanical properties, and self-healing performance of the polyurethanes. The results showed that the tensile strength of PU/SM was 30.7 MPa, which was 20.1 MPa higher than that of PU/BDO. TG/DTG analysis revealed that the introduction of MD significantly improved the heat resistance of PU/SM. Comparison at the same temperature showed a significant reduction in relaxation time of PU/SM compared to that of PU/SE, indicating that the introduction of MD promoted the exchange rate of dynamic covalent bonds. Compared with PU/SE, PU/SM exhibited a faster relaxation rate, and the activation energy was reduced by 35. 84 kJ/mol. The results of self-healing performance tests demonstrated that PU/SM had superior self-healing properties compared to PU/BDO and PU/SE, with a self-healing rate of 77% for the sheared PU/SM film after 24 h of heating at 80 ℃.

Key words: 1, 8-mentane-p-diamine, relaxation time, self-repairing, environmentally friendly

CLC Number: