Synthesis and Flame Retardant Properties of Melamine Modified EH Lignin

A novel intumescent flame retardant (IFR), melamine modified enzymatic hydrolysis lignin (MEHL), was synthesized and well characterized by FTIR and TGA. The results showed that the decompose temperature of MEHL is much higher than that of enzymatic hydrolysis lignin (EHL). In order to improve flame retardancy and dripping resistance of EPDM, MEHL and microencapsulated red phosphorus (MRP) were added into EPDM as IFR system. The flame ability and thermal stability of IFR and EPDM composites were investigated by UL-94 vertical burning test and LOI measurements. The results indicated that FV-0 was reached and the LOI value was 35 when per hundred rubber (phr) together with 12 phr MRP and 50 phr EHLM were added. SEM photos showed that the char residue was continuous, and a barrier between flame and rubber was formed, while there were also small holes in its surfaces. On all accounts, EHL used as a carbonization agent instead of petroleum chemicals, such as pentaerythritol, was more environmental friendly and beneficial to economy.