FLAME-RETARDANT CHARRING AGENT AND PREPARATION PROCESS THEREOF

The present invention discloses a flame-retardant charring agent and a preparation process thereof, and a structural formula is shown as follows: , 5 wherein n=1-3. The preparation process includes the following steps: 1) weighing phosphoric acid and NiCO3`2Ni(OH)2`4H2O according to the substance amount ratio of 1:6, adding deionized water and stirring and mixing the substances for dissolution until no bubble is generated, so as to obtain a mixed solution A; and 2) mixing the mixed solution A and pentaerythritol and adding an obtained mixture into a methylbenzene solution for 10 reaction, after heating and reacting for 9 h at the temperature of 100 °C, continuing the reaction by increasing the temperature to 110 °C until methylbenzene is completely removed, then increasing the temperature of the system to 150 °C, adding tris(2-hydroxyethyl)isocyanurate and a catalyst, continuously stirring and reacting for 12 h to obtain a thick product, and crystallizing the thick product into a solid product so as to 15 obtain a finished product PECN. The novel intumescent flame-retardant charring agent provided by the present invention is used for flame retardance of polypropylene, and compared with a traditional APP/PER system, the flame-retardant efficiency is obviously improved.