摘要
采用9,10-二氢-9-氧杂-10-膦菲-10-氧杂(DOPO)-乙烯基三甲氧基硅烷(VTMS)加成物DOP O-VTMS通过水解缩合反应,制备了新型含DOPO基团的笼网结构倍半硅氧烷(DOP O-PolyPOSS)。将不同比例的DOP O-Poly POSS添加到环氧树脂(EP)中,制备了一系列阻燃EP。采用热重分析(TGA)、动态热机械分析(DMA)、万能拉力机、极限氧指数(LOI)、U L-94和锥形量热计对阻燃环氧树脂的热性能、力学性能和阻燃性能进行了系统研究,并通过热重-红外联用(TG A-IR)、热重-质谱联用(TG A-MS)和扫描电子显微镜(SEM)研究了其阻燃机理,结果表明:DOP O-PolyPOSS可在EP中均匀分散;向EP中加入DOP O-PolyPOSS显著提高了阻燃EP的残炭率,降低了热释放速率(HRR),延长了点燃时间(TTI),达到了良好的阻燃效果;当DOP O-PolyPOSS加入量(质量分数)为3%时,阻燃EP的LOI值可从纯EP的25.5%提高至31.7%,并达到了U L-94的V-0阻燃等级。此外,加入DOP O-PolyPOSS可提高EP的拉伸和弯曲性能。对EP凝聚相和气相裂解产物的分析结果表明,DOP O-PolyPOSS阻燃环氧树脂是基于磷硅协同效应而同时在气相和凝聚相阻燃。
Novel cage-ladder structure phosphorus-containing polyhedral oligomeric silsesquinoxanes(DOP O-PolyPOSS)have been synthesized by hydrolytic condensation of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide-vinyltrimethoxysilane(DOP O-VTMS).The DOP O-PolyPOSS was incorporated into epoxy resins(EPs)in different ratios to form a series of flame retardant EPs.The effect of DOP O-PolyPOSS on the thermal,mechanical and flame retardant properties of EP was investigated.The experimental results showed that DOP O-PolyPOSS was homogeneously dispersed in the EP.The incorporation of DOP O-PolyPOSS enhanced char residue formation during thermal degradation of EP,reduced the heat release rate(HRR),and delayed the time to ignition(TTI)of EP in a fire.Interestingly,after the addition of only 3 wt%DOP O-PolyPOSS,the limiting oxygen index(LOI)value of the EP composite increased from 25.5%for pure EP to 31.7%,and vertical burning(U L-94)V-0 ratings were achieved.In addition,the EP composites showed improved tensile and flexural properties.Investigations of char residue and pyrolysis volatiles of cured EP further revealed that DOP O-PolyPOSS exerted simultaneous flame-retardant effects in both condensed and gas phases due to the synergistic effects between silicon and phosphorus.
作者
刘兴华
赵晓娟
李胜楠
杨欣
于然
张瑛
黄伟
LIU XingHua;ZHAO XiaoJuan;LI ShengNan;YANG Xin;YU Ran;ZHANG Ying;HUANG Wei(Laboratory of Advanced Polymeric Materials,Institute of Chemistry,Chinese Academy of Sciences,Beijing 100190,China)
出处
《北京化工大学学报（自然科学版）》
CAS
CSCD
北大核心
2020年第6期62-72,共11页
Journal of Beijing University of Chemical Technology(Natural Science Edition)
基金
国家重点研发计划(2017YFB0404800)
北京市自然科学基金(2182095)。
