Improvement of flame retardancy and thermal stability of polypropylene by P-type hydrated silica aluminate containing lanthanum
作者：Sheng Zhang;Wufei Tang;Jia Guo;Xiaodong Jin;Hongfei Li;Xiaoyu Gu;Jun Sun
關(guān)鍵字：Kaolinite, Lanthanum (La), P-type hydrated silica aluminate, Flammability, Polypropylene
論文來源：期刊
具體來源：Polymer Degradation and Stability, 2018, 154, 276-284
發(fā)表時間：2018年
Phosphotungstic acid is a typical kind of superior catalysts, and it is hardly to intercalate into the layered double hydroxides (LDH) by ion-exchange process because of its low negative charge. In this work, a phosphotungstic acid intercalated MgAl-LDH (PWA-LDH) was prepared by reconstruction method, and it was then introduced into poly (lactic acid) (PLA) resin in association with intumescent flame retardant (IFR) by melt blending to prepare a flame-retardant biodegradable PLA composite. The effects of PWA-LDH on the flame retardancy of PLA composites were characterized by limiting oxygen index (LOI), vertical burning test (UL-94) and cone calorimeter test. The results showed that the composite sample containing 18.0 wt% IFR and 2.0 wt% PWA-LDH achieved the maximal LOI value of 48.3%, passed the UL-94 V-0 rating, and significantly decreased the peak heat release rate from 306.3 kW/m2 of neat PLA to 40.1 kW/m2. Thermogravimetric analysis showed that both the thermal stability and the char formation were enhanced. The char morphology observation revealed that PWA-LDH was beneficial to form dense and compact char layers. It was demonstrated that there existed a synergistic effect between IFR and PWA-LDH in promoting the char formation and enhancing the fire resistance