成炭型有机大分子/层状无机物复合成炭剂的制备及应用研究

Preparation and application of char-forming organic macromolecules/layered inorganic composite char-forming agent

层状无机物在聚合物基体中易团聚,限制了其在聚合物材料中的规模化应用。本工作通过将有机改性蒙脱土(OMMT)与一种具有超支化结构的磷氮大分子化合物HTPPP(以三嗪结构为基础,通过焦磷酸结构连接)在醇水体系中混合溶胀,再经过高温脱水,制备成HTPPP插层、剥离的OMMT成炭型有机大分子/层状无机物复合成炭剂(HTPPP-OMMT)。XRD测试表明层状结构的OMMT能够在HTPPP中被完全剥离。OMMT的复合降低了HTPPP的水溶性,并提高了其热稳定性。将有机/无机复合成炭剂HTPPP-OMMT作为单组分无卤膨胀阻燃剂应用于聚丙烯(PP),阻燃测试表明HTPPP-OMMT复合成炭剂的阻燃效率高于HTPPP。这是由于其在材料燃烧过程中能够催化形成更加致密的膨胀多孔炭层,而炭层在高温下的热氧稳定性更好。此外,有机/无机复合改善了HTPPP-OMMT在PP的相容性,能提高材料的力学和耐析出性能。

Layered inorganic matter is easy to agglomerate in the polymer matrix,which limits its large-scale application in polymer materials.In this work,organically modified montmorillonite(OMMT)was mixed with a hyperbranched phosphorus-nitrogen macromolecular compound HTPPP(based on a triazine structure and linked by a pyrophosphate structure)in an alcohol-water system.After high-temperature dehydration,the char-forming organic macromolecules/layered inorganic composite char-forming agent(HTPPP-OMMT)was prepared.XRD test showed that the layered structure of OMMT was completely exfoliated in HTPPP.The intercalation of OMMT reduces the water solubility of HTPPP and improves its thermal stability.The organic/inorganic composite char-forming agent HTPPP-OMMT was used as a one-component halogen-free intumescent flame retardant in polypropylene(PP),and the flame retardant test shows that the flame retardant efficiency of HTPPP-OMMT composite char is higher than that of HTPPP.This is because a denser expanded porous char layer can be formed during combustion,and the char layer has better thermo-oxidative stability at high temperatures.The organic/inorganic compound improves the compatibility of HTPPP-OMMT in PP and the material's mechanical properties and precipitation resistance.