摘要
以三苯基膦(PPh3)为原料,制备了一种含硝基的阻燃剂3(3-硝基苯基)膦(NPPh3)。并通过红外光谱(FTIR)、核磁共振(~1HNMR)、热重分析(TG)和红外热失重联用(TG-FTIR)对其结构、热稳定性、热降解行为、成炭能力和热降解产物进行研究。结果表明:NPPh3的初始分解温度为291.2℃,800℃下残炭量达28.16%(N2条件下),相比于原料,硝化后阻燃剂的热稳定性和成炭性能明显提高,热降解主要产物为H_2O、CO_2、CO和芳环。为了在阻燃剂添加量少的情况下,达到良好的阻燃效果,以4,4,–二胺基二苯甲烷(DDM)为固化剂,将NPPh3和9,10–二氢–9–氧杂–10–磷杂菲–10–氧化物(DOPO)复合应用于环氧树脂中,研究其协同阻燃环氧树脂的性能。通过极限氧指数(LOI)和垂直燃烧(UL–94)测试结果可知,阻燃剂总添加量(质量分数)为4.7%,当NPPh3和DOPO的质量比为1∶2时,阻燃环氧树脂的极限氧指数为33.8%,材料通过垂直燃烧测试的V-0级,表现出良好的阻燃性。TG的测试结果表明,燃烧过程中,NPPh3和DOPO之间存在反应,并使环氧树脂的初始分解温度略有降低,热分解速率下降,延缓了树脂在高温下的热降解,提高了高温下材料的成炭量。通过FTIR和扫描电镜(SEM)研究炭层的组成和形貌,结果表明,NPPh3/DOPO/EP通过形成含有–P,–NO2基团的均匀致密炭层结构,在聚合物表面产生有效覆盖,保护基体材料,发挥凝聚相阻燃作用,提高体系的阻燃性能。
A flame-retardant tris（3-nitrophenyl） phosphine（NPPh3） containing nitro group was synthesized from triphenyl phosphine（PPh3）. Its chemical structure, thermal stability, thermal degradation behavior, charring ability, and thermal degradation products were characterized by Fourier transform infrared spectra（FTIR）, nuclear magnetic resonance（1 HNMR）, thermogravimetric analysis（TG）, and thermogravimetric analysis/infrared spectrometry（TG-FTIR）. The results showed that the initial thermal decomposition temperature of NPPh3 was 291.2 ℃. The carbon residue at 800 ℃（under N2 atmosphere） reached 28.16%, which demonstrated that the thermal stability and charring ability of PPh3 after nitrification was improved. In addition, TG-FTIR results indicated that its thermal degradation products were H2 O, CO2, CO, and aromatic ring.In order to achieve a good flame retardant effect under less flame retardant, NPPh3 was used together with 9,10–dihydro–9–oxa–10–phosphaphenanthrene–10–oxide（DOPO） to prepare a flame-retardant system for epoxy resins（EP） with 4,4–diaminodiphenylmethane（DDM） as curing agent, and the synergistic effect between them was studied. LOI and UL–94 results showed that when the flame retardant content was 4.7%, the ratio of NPPh3/DOPO was at 1∶2, flame retardant epoxy resin acquired a LOI value of 33.8% and UL-94 vertical burning successfully passed V-0 flammability rating. The TG test showed that there was an obvious synergistic effect between NPPh3 and DOPO. The introduction of NPPh3/DOPO lowered the initial decomposition temperature and increased the amount of residue mass at high temperature compared with EP. Additionally, the structure and morphology of the residue chars were studied by FTIR and scanning electron microscopy（SEM）. The results illustrated that NPPh3/DOPO stimulated the formation of compact and strong char layer which contained –P and –NO2 groups, and provided a good barrier to hamper the transfer of heat and oxygen int
作者
罗航
蔡绪福
LUO Hang;CAI Xufu(School of Polymer Sci.and Eng.,Sichuan Univ.,Chengdu 610065,China)
出处
《工程科学与技术》
EI
CAS
CSCD
北大核心
2018年第4期201-207,共7页
Advanced Engineering Sciences
关键词
硝化
磷系阻燃剂
环氧树脂
协同作用
nitrification
phosphorous flame retardant
epoxy resins
synergistic effect
