Polymer Degradation and Stability ( IF 5.9 ) Pub Date : 2019-11-11 , DOI: 10.1016/j.polymdegradstab.2019.109023 Peng Wang , Lei Chen , Hang Xiao , Tonghui Zhan
Improving the flame retardancy of epoxy resin will greatly expand its application in the fields requiring flame retardancy. Herein, a nitrogen/sulfur-containing DOPO based oligomer (SFG) for highly efficient flame-retardant epoxy resin was successfully synthesized via a facile one-pot method with DOPO, sulfaguanidine and p-phthalaldehyde. The incorporation of SFG accelerated the cross-linking reaction of epoxy system and improved the tensile strength, flame retardancy and fire safety of epoxy thermoset. SFG showed high flame-retardant efficiency due to the synergism among nitrogen, sulfur and phosphorus. With only 0.38 wt% phosphorus content, the corresponding epoxy thermoset achieved an LOI value of 32.8%, passed UL-94 V-0 rating and possessed lower fire growth rate and total heat release in cone calorimeter test in comparison with neat thermoset. SFG exerted dual flame-retardant effect not only by diluting oxygen and combustible volatiles and quenching active radicals, but also by promoting the formation of thermal insulating char layer with honeycombed cavity inside. Moreover, the appearance of blowing out phenomenon during combustion was disclosed that the intensive release of gases blew out the flame based on the dilution and quenching effects when the inner gas pressure was sufficient to break through the char layer.
中文翻译:
含氮/硫的DOPO基低聚物,用于高效阻燃环氧树脂
改善环氧树脂的阻燃性将极大地扩展其在需要阻燃性的领域中的应用。在此,通过简便的一锅法,DOPO,磺胺胍和p成功地合成了用于高效阻燃环氧树脂的含氮/硫的DOPO基低聚物(SFG)。-邻苯二甲醛。SFG的加入加快了环氧体系的交联反应,并提高了环氧热固性树脂的拉伸强度,阻燃性和防火性。SFG由于氮,硫和磷之间的协同作用而具有较高的阻燃效率。与纯热固性塑料相比,相应的环氧热固性材料仅含0.38 wt%的磷,其LOI值达到32.8%,通过UL-94 V-0等级,并且在锥形量热仪测试中具有较低的着火率和总放热率。SFG不仅通过稀释氧气和可燃挥发物并淬灭活性自由基发挥双重阻燃作用,而且还通过促进内部带有蜂窝状空腔的隔热炭层的形成发挥了双重阻燃作用。而且,