异氰酸酯类成炭剂的合成及在无卤阻燃聚丙烯中的应用

Synthesis of Isocyanate-Based Charring Agent and Its Application in Halogen-Free Flame Retardant of PP

以三(2-羟乙基)异氰脲酸酯与对苯二甲酸为原料,通过熔融聚合反应,在无溶剂条件下制备出异氰酸酯类化合物(TT1),采用核磁氢谱、红外光谱、元素分析对TT1结构进行表征,通过热重对TT1的热稳定性进行测定。将TT1与结晶II-型聚磷酸铵(APP-II)按照不同比例复配得到膨胀型阻燃剂(IFR),将IFR添加到聚丙烯(PP)中,得到PP/IFR阻燃复合物。通过氧指数、UL-94垂直燃烧、锥形量热测试对PP/IFR复合物的阻燃及燃烧性能进行评定,通过TG对其热稳定性进行研究,以扫描电镜观测阻燃复合物燃烧后生成的炭层微观结构。测试结果表明,TT1和APP存在协效作用,复配的膨胀阻燃剂IFR对PP具有优良的阻燃效果。当IFR添加量为25%(质量分数,下同)时,PP/IFR的氧指数达到32.3%,UL-94垂直燃烧达到V-0级(样条厚3.0mm),且阻燃复合材料燃烧中热释速率明显减缓。

A novel isocyanate-based charring agent,which was obtained by melt polymerization without any solvent,was synthesized using tris（2-Hydroxyethyl）isocyanurate and terephthalic acid as raw materials.Its chemical structure and thermal properties were tested by 1 H-NMR,FT-IR,TG and element analysis（EA）,it was acted as charring agent and used in intumescent flame retardant（IFR）system.The PP/IFR composites were obtained by melt mixing,and its flame retardant and combustibility properties were evaluated by limiting oxygen index（LOI）,UL-94 vertical burning test and cone calorimetry.The thermal stability of the composites was tested by TG.The results indicate that TT1 has a well synergistic effect with ammonium polyphosphate（APP）,and the IFR has good flame retardancy on PP.When IFR is at 25%loading level,the PP/IFR composite’s LOI is 32.3%,and reaches UL-94V-0rating.