Liu Yuan, Xu Shiai, Chen Qinghua, Xu Jie, Sun Beibei
School of Materials Science and Engineering, East China University of Science and Technology Shanghai 200237 China
Qinghai Provincial Key Laboratory of Salt Lake Materials Chemical Engineering, School of Chemical Engineering, Qinghai University Xining 810016 China.
RSC Adv. 2024 May 9;14(21):15143-15154. doi: 10.1039/d4ra01669f. eCollection 2024 May 2.
Ethylene-vinyl acetate copolymer (EVA) is widely used in various applications; however, its flammability limits its application in wire and cable industries. In this study, 3-methacryloxypropyltrimethoxysilane (KH570) was successfully grafted onto the surface of anhydrous magnesium carbonate (AMC) by alkali activation treatment. The KH570 modified AMC (AMC@KH570) was then introduced into the EVA matrix along with hexaphenoxycyclotriphosphazene (HPCTP) to assess their effects on the flame retardancy and mechanical properties of EVA composites. The results illustrate a significant synergistic effect in enhancing the flame retardancy of EVA composites by using AMC@KH570 and HPCTP, and the limiting oxygen index (LOI) and vertical burning test (UL-94) of EVA filled with 5 wt% HPCTP and 45 wt% AMC@KH570 (mAMC/H-45-5) reached 27.6% and V-0, respectively. The flame retardant mechanism was investigated by thermogravimetric/infrared (TG-IR) spectroscopy and residual carbon composition analysis. The results show that the thermal decomposition of AMC@KH570 and HPCTP consists of gas dilution, free radical quenching, and catalytic carbonization. Furthermore, KH570 works as a bridge to improve the compatibility of AMC and EVA matrix, which offsets the mechanical loss of EVA to some extent. The present research provides a new path to modify AMC and fabricate EVA composites with excellent flame retardant properties.
乙烯-醋酸乙烯酯共聚物（EVA）广泛应用于各种领域；然而，其易燃性限制了它在电线电缆行业的应用。在本研究中，通过碱活化处理成功地将3-甲基丙烯酰氧基丙基三甲氧基硅烷（KH570）接枝到无水碳酸镁（AMC）表面。然后将KH570改性的AMC（AMC@KH570）与六苯氧基环三磷腈（HPCTP）一起引入EVA基体中，以评估它们对EVA复合材料阻燃性能和力学性能的影响。结果表明，使用AMC@KH570和HPCTP对提高EVA复合材料的阻燃性能具有显著的协同效应，填充5 wt% HPCTP和45 wt% AMC@KH570（mAMC/H-45-5）的EVA的极限氧指数（LOI）和垂直燃烧试验（UL-94）分别达到27.6%和V-0级。通过热重/红外（TG-IR）光谱和残炭成分分析研究了阻燃机理。结果表明，AMC@KH570和HPCTP的热分解包括气体稀释、自由基猝灭和催化碳化。此外，KH570作为桥梁提高了AMC与EVA基体的相容性，在一定程度上抵消了EVA的力学损失。本研究为改性AMC和制备具有优异阻燃性能的EVA复合材料提供了一条新途径。
