Polydimethylsiloxane wrapped aluminum diethylphosphinate for enhancing the flame retardancy of polyamide 6

Abstract Aluminum diethylphosphinate (ADP) was wrapped with polydimethylsiloxane (PDMS) by a facile method to improve its hydrophobic properties. The morphology and properties of PDMS‐modified ADP (PDMS‐ADP) were investigated by thermogravimetric analysis, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, and water contact angle tests. The water contact angle of PDMS‐ADP was increased from 126° to 151° as compared with that of ADP, which indicates that PDMS‐ADP showed good hydrophobic properties. Then, ADP and PDMS‐ADP were introduced into polyamide 6 (PA6) matrices to study the flame retardancy of the composites. The flammability of the PA6/ADP and PA6/PDMS‐ADP composites was much lower than that of pure PA6. The composites PA6‐1 (with the addition of 15 wt% ADP) and PA6‐4 (with the addition of 12 wt% PDMS‐ADP) could pass the UL‐94 V‐0 in the vertical burning test. Meanwhile, the peak heat release rates of PA6‐1 and PA6‐4 were 212 and 192 kW/m 2 , with reductions of 67.3 and 70.4%, respectively, compared with pure PA6. These results indicated that the coating of PDMS could enhance the flame‐retardant efficiency of ADP.