(壳聚糖-聚磷酸铵)/剑麻纤维素微晶层层自组装复合材料的热性能和阻燃性能

Thermal and flame retardant properties of(chitosan-ammonium polyphosphate)/sisal fiber cellulose microcrystal layer-by-layer self assembly composite

采用层层自组装法(LBL),在剑麻纤维素微晶(SFCM)表面交替吸附壳聚糖(CH)和聚磷酸铵(APP)构筑CH-APP阻燃涂层,成功制备(CH-APP)n/SFCM阻燃复合材料。通过Zeta电位分析仪、 FTIR、 TGA、 POM、垂直燃烧法(VFT)、 SEM手段对复合材料的结构和性能进行表征。FTIR、 Zeta电位结果表明, CH和APP在SFCM表面电位正负交替变化, CH-APP涂层成功包覆在SFCM表面;POM和SEM结果显示,组装后(CH-APP)n/SFCM复合材料表面变得粗糙,其表面包覆了一层较厚涂层;TGA结果表明,随着吸附CH-APP组装层数的增加,(CH-APP)n/SFCM复合材料的初始分解温度(T5%)由279.4℃降低至243.1℃,残炭率由11.24%提高至32.06%;VFT测试结果表明,随着组装层数的增加,(CH-APP)n/SFCM复合材料阻燃性能明显提高,组装10层的(CH-APP)10/SFCM复合材料甚至可以达到离火自熄的程度。

The layer-by-layer of self assembly(LBL) method was adopted to construct CH-APP flame retardant coating by alternating adsorption of cationic chitosan(CH) and anionic ammonium polyphosphate(APP) on the surface of sisal fiber cellulose microcrystal(SFCM), and(CH-APP)n/SFCM flame retardant composites were prepared. The structure and properties of the(CH-APP)n/SFCM composites were measured by Zeta potential analyzer, FTIR, TGA, POM, vertical flame testing(VFT), SEM. The results of Zeta potential show the surface of SFCM potential is positive and negative in the alternately adsorption process, which indicates the CH-APP coating is successfully coated on the surface of SFCM. POM and SEM reveal a thick coating was covered on the surface of the SFCM by LBL and the surface of SFCM becomes more rough. With the increase of the number of CH-APP self assembled layers, the initial decomposition temperature(T5%) of(CH-APP)n/SFCM composite reduces from 279.4℃ to 243.1℃, and the char residue of(CH-APP)n/SFCM composite increases from 11.24% to 32.06%. The results of VFT show that(CH-APP)n/SFCM composites present outstanding flame retardancy after LBL method and the(CH-APP)n/SFCM composite with 10 layers assembled exhibits the best flame retardancy with self-extinguishing fire flame retardant.