Intumescent coating of (polyallylamine-polyphosphates) deposited on polyamide fabrics via layer-by-layer technique

In this work, an intumescent coating of (polyallylamine-polyphosphate)n (“n“ denotes the number of bilayers (BL) deposited) was elaborated through Layer-by-Layer assembly in order to improve the fire performance of polyamide 6.6 fabrics (PA). The thickness of this intumescent assembly increases linearly as a function of the number of bilayers deposited. Thermogravimetric analysis results indicate that the presence of such assembly catalyzes and changes the degradation pathway of virgin polyamide fabrics. The fire performance was evaluated by Pyrolysis Combustion Flow Calorimeter. The fire results show on the one hand a significant decrease of peak of heat release rate (pHRR) and on the other hand a shift to lower temperatures (assigned to a catalytic effect) as a function of the number of bilayers deposited. A maximum decrease of pHRR (−36%) is obtained for the 40 BL coated fabric in comparison with uncoated polyamide fabric.