膨胀蛭石偶联的羟基封端硅橡胶及其阻燃性能优化研究

摘要

以羟基封端硅橡胶为主体、高温膨胀蛭石（EV）为添加剂、四乙氧基硅为偶联剂，经两步缩合反应制备了蛭石／硅橡胶复合弹性体（EV －PDMS），并对其阻燃性能进行了研究．经分别用全反射衰减红外光谱、水接触角、扫描电子显微镜对制备物进行测试，结果表明：膨胀蛭石的片状晶体均匀地分散于硅橡胶的内部，它们之间形成了稳定的 Si—O—Si 共价键，掺杂后的 EV －PDMS 弹性体表面维持了高度的憎水性能．力学性能测试表明：60份 EV 掺杂后，拉伸强度、杨氏模量、邵氏硬度分别增加至添加前空白 PDMS 弹性体的4．50倍、1．97倍、2．17倍．燃烧实验表明：添加5份的十溴联苯醚和5份的氢氧化铝，蛭石／硅橡胶弹性体的阻燃性能可达到 FV －0级，极限氧指数可达69．5％．%Expanded vermiculite (EV)doped poly(dimethylsiloxane)(PDMS)(EV-PDMS)was prepared through two steps of condensation reactions,in which hydroxyl terminated poly(dimethylsiloxane)was as main part,high temperature EV was as additive,and tetraethoxy-silicane (TEOS)was as coupling agent.And the flame reatardant performance of EV-PDMS was studied.Detections of attenuated total reflectance infrared spec-trum (ATR-IR),water contact angle,and scanning electron microscope (SEM)revealed that,EV flakes homo-geneously dispersed into PDMS,and crosslinked with PDMS through Si—O—Si covalent bonds;the resultant EV-PDMS elastomer maintained a highly hydrophobic surface.Mechanical properties revealed that,after addi-tion of 60 copies EV,tensile strengths,Young’s moduli,and Shao’s hardness respectively increase to 4.50, 1.97 and 2.17.Combustion tests revealed that,after addition of 5 copies of decabromodiphenyl oxide (DeDBE)and 5 copies of aluminum hydroxide,flame retardant properties of EV-PDMS reached to FV-0 class, and their limited oxygen indexes (LOI)reached to 69.5%.