聚合物包覆铝锂合金及其稳定性研究

To improve the stability of aluminum-lithium alloy (Al-Li), the surface coating treatment was performed with self-made polyhydroxypolyester and polydopamine, respectively, to obtain Al-Li@PL and Al-Li@PDA. The morphology and structure were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), and the interfacial mechanism was discussed. The moisture and heat stability of Al-Li@PL and Al-Li@PDA were investigated by dryer balance method. The thermal decomposition of samples were analyzed by oxygen bomb calorimetry and thermogravimetric differential scanning calorimetry, and the compatibility of the sample with 1, 2, 4-butantriol nitrate (BTTN) was evaluated by non-isothermal thermal decomposition kinetics. The results show that good adhesion and functional groups (hydroxyl, carboxyl and amino) are the key factors to form stable coating layers. The heat of combustion values of Al-Li, Al-Li® PL and Al-Li@PDA are 30957, 30852 and 30 589J/g, respectively, and the loss rate value after coating is less than 1 %. The oxidation heat release mode does not change, and the maximum oxidation heat release peak temperature move back by 13 °C and 2 °C, respectively. Both Al-Li@PL and Al-Li@ PDA do not react strongly with water at 80。C, their hygroscopic weight gain rates decrease from 177.42% to 5.32% and 2.58% at 75% humidity for 30 days, respectively, their compatibility with BTTN increase from level 5 to level 1.