Intumescent flame retardant behavior of charring agents with different aggregation of piperazine/triazine groups in polypropylene

Publication date: Available online 25 September 2019Source: Polymer Degradation and StabilityAuthor(s): Wei Tang, Lijun Qian, Yajun Chen, Yong Qiu, Bo XuAbstractTo explore the structure mode of charring agent with higher flame retardant efficiency, two charring agents (PT-Cluster and PT) with different aggregation structure of piperazine/triazine groups were synthesized and characterized, and then were applied to preparing intumescent flame retardant polypropylene (PP) composites with ammonium polyphosphate (APP). Both PT-Cluster/APP/PP and PT/APP/PP composites performed excellent intumescent flame retardant effects. The values of LOI reached over 32% while the mass ratio of charring agent was only 3 wt% in the case of 25 wt% IFR loading. The pk-HRR values of 5%PT-Cluster/20%APP/75%PP and 5%PT/20%APP/75%PP were 242 kW/m2 and 330 kW/m2, respectively, which were all decreased by over 73% compared with neat PP. Besides, the total heat release (THR) and average effective heat of combustion (av-EHC) of charring agent/APP/PP were also decreased. More importantly, the aggregated piperazine/triazine groups in PT-Cluster further raised the flame retardant efficiency of charring agent/APP system. PT-Cluster/APP system brought higher residue yields and lower THR, av-EHC and total smoke release than PT/APP in cone calorimeter test, implying that PT-Cluster/APP exhibited better charring and barrier effect, and more effective quenching effect than PT/APP during combustion. The enha...

Source: Polymer Degradation and Stability - September 26, 2019 Category: Chemistry Source Type: research