Sb_2O_3-ZnMgAl类水滑石的制备及其在软聚氯乙烯阻燃中的应用

采用快速成核/晶化法、油酸钠改性以及高速球磨分别得到改性前后锌镁铝类水滑石(ZnMgAl LDHs,LDHs)和Sb_2O_3-LDHs样品。通过XRD、FTIR、FESEM和TG等对所制备的LDHs和Sb_2O_3-LDHs进行了表征。考察了添加质量比为6∶100(PVC为100)时,改性前后LDHs和Sb_2O_3-LDHs的添加对所制备的聚氯乙烯(PVC)基复合材料阻燃及力学性能的影响,结果显示:添加改性前后LDHs和Sb_2O_3-LDHs所制备的PVC基复合材料均达到V-0级别,极限氧指(LOI)值可达33.4%,且添加改性LDHs和Sb_2O_3-LDHs的复合材料力学性能均有所改善。材料燃烧后残碳及断面的FESEM显示:改性LDHs和(Sb_2O_3)_(10)-LDHs的添加使PVC基复合材料燃烧后表面形成结构密实的保护性炭层,提高阻燃性能;改性LDHs在软PVC中分散均匀,相容性较好,使改性LDHs具有更优的增强和增韧作用;而Sb_2O_3-LDHs在PVC基体间存在界面差异,导致材料的断裂伸长率、拉伸强度随Sb_2O_3质量分数的增加有所下降。

Preparation of Sb2O3-LDHs and its assisting flame retardant effects on soft polyvinyl chloride

ZnMgAl layered double hydroxides(LDHs),moditied-LDHs and Sb2O3-LDHs were prepared via rapid nucleation/crystallization method,and modification by sodium oleate and high-speed ball-milling process,respectively,and then were characterized by XRD,FTIR,FESEM and TG etc.The flame retardant and mechanical properties of soft polyvinyl chloride(PVC) matrix composites with 6％ mass ratio of Sb2O3-LDHs were investigated.The results show that all the composites can meet the requirement of V-0 grade in UL-94 test and the LOI value reach to 33.4％;the mechanical properties of modified-LDHs/soft PVC and Sb2O3-LDHs/soft PVC composites can be improved in certain extent.The FESEM images of the carbon residue after combustion show that a dense protective coal layer forms on the surface of composites after combustion to achieve flame retardant effect when adding modified-LDHs or (Sb2O3)10-LDHs.FESEM images of materials' cross-section show that the modified-LDHs is dispersed uniformly in the soft PVC,and exhibit well compatibility with soft PVC,enabling strengthen and toughen the composites.The elongation at break and tensile strength of Sb2O3-LDHs/soft PVC composites are better than that of the soft PVC,but decline gradually with the increasing of mass fraction of Sb2O3-LDHs owing to the interface difference between Sb2O3 and the polymer matrix.