Influence of Ammonium Polyphosphate/Lignin Ratio on Thermal and Fire Behavior of Biobased Thermoplastic: The Case of Polyamide 11

Abstract

Flame retardancy of polymers is a recurring obligation for many applications. The development trend of biobased materials is no exception to this rule, and solutions of flame retardants from agro-resources give an advantage. Lignin is produced as a waste by-product from some industries, and can be used in the intumescent formation development as a source of carbon combined with an acid source. In this study, the flame retardancy of polyamide 11 (PA) is carried out by extrusion with a kraft lignin (KL) and ammonium polyphosphate (AP). The study of the optimal ratio between the KL and the AP makes it possible to optimize the fire properties as well as to reduce the cost and facilitates the implementation of the blend by a melting process. The properties of thermal decomposition and the fire reaction have been studied by thermogravimetric analyzes, pyrolysis combustion flow calorimetry (PCFC) and vertical flame spread tests (UL94). KL permits a charring effect delaying thermal degradation and decreases by 66% the peak of heat release rate in comparison with raw PA. The fire reaction of the ternary blends is improved even if KL-AP association does not have a synergy effect. The 25/75 and 33/67 KL/AP ratios in PA give an intumescence behavior under flame exposure.

Flammability Tests and Investigations of Properties of Lignin-Containing Polymer Composites Based on Acrylates

“…Combination of the phosphorus-based additives with the nitrogen-containing products, like melamine cyanurate, melamine phosphate, or melamine polyphosphate, exhibit high performance because of synergistic effects [ 30 ]. In turn, the bio-based flame retardants composed of lignin represent one of the most promising trends for new-generation flame retardants due to their sustainability and environmental benefits [ 31 , 32 , 33 , 34 , 35 , 36 , 37 ]. Moreover, the exploitation of other biomacromolecules as effective flame retardants for textiles was also studied [ 38 ].…”

Fire Resistance and Mechanical Properties of Intumescent Coating Using Novel BioAsh for Steel

“…The peak from 1246.0 to 1246.7 cm −1 proved the deformation of the carbonyl group (C−H) present in cellulose, hemicellulose, and lignin [29]. Aromatic ring in lignin was identified at the peak from 1600 to 1585 cm −1 and 1500 to 1400 cm −1 [44]. All BAIC samples showed a peak between 1451.61 and 1451.96 cm −1 that manifested the stretching of C=C (aromatic ring) in lignin present in BioAsh.…”

“…An appropriate ratio of 3.5 wt.% BioAsh and 6.5 wt.% TiO 2 in BAIC 3-5 was able to slow down the water permeation rate due to the formation of a better particles distribution in the inter-surface matrix. Incorporation of the poorly soluble Al(OH) 3 in IC can help to enhance the water resistance [44]. Hence, it is assumed minor Al(OH) 3 that potentially present in 3.5 wt.% may assist in promoting a better water resistance in BAIC 3-5 without compromising the fire-resistance outcomes.…”

Environmentally Benign Flame Retardant Polyamide‐6 Filament for Additive Manufacturing

“…[9,16] There is a long history of utilizing conventional FR additives such as ammonium polyphosphate (APP) to reduce the flammability of various polyamides. [17][18][19][20] Additionally, there have been several documented cases of PA6 flammability being effectively curtailed through incorporation of small molecules, intumescent additives, polymers, and nanoparticles. [16,[21][22][23][24] Regrettably, none of these studies have evaluated the 3D printability of the flame retardant PA6 composites they produced.…”