Study of thermal, flammability and mechanical properties of intumescent flame retardant PP/kenaf nanocomposites

Figures & data

Figure 1. XRD patterns of PP, nanoclays and flame retardant composites: (a) 2θ = 2–14°; (b) 2θ = 14–20°.

Figure 2. TEM images of IFR and nanocomposites: (a) KeC-IFR; (b) KeC-IFR+MMT.

Figure 3. Thermal degradation behavior of neat PP and various nanocomposites: (a) TGA; (b) Derivative thermogravimetry.

Table 1. TGA data of different composites showing the fraction of char residues.

Sample	Tonset (°C)	Tmax (°C)	Rmax (wt.%/min)	Char residue (%)
				450°C	500°C	550°C
PP	342	426	10.62	2.28	1.81	1.77
KeC	308	443	9.12	24.10	5.70	4.62
KeC-IFR	280	437	7.86	33.98	22.47	21.62
KeC-IFR+HNT	281	473	7.55	54.70	26.01	24.75
KeC-IFR+MMT	261	425	8.00	27.96	24.17	22.81

Table 2. Flammability performance.

Sample	Cone calorimeter					UL-94 V
	TTI (s)	pk-HRR (kW/m^2)	FPI (m^2s/kW)	MLR (g/s)	THR (MJ/m^2)	Ave. sample dripping in time (s)	Rating
PP	21	1145.076	0.018	0.057	119.943	15	NR
KeC	18	728.997	0.025	0.088	104.932	52	NR
KeC-IFR	18	381.050	0.047	0.054	84.500	85	NR
KeC-IFR+HNT	20	371.220	0.054	0.051	84.100	82	NR
KeC-IFR+MMT	21	346.950	0.061	0.041	84.010	65*	NR

TTI: time to ignition, pk-HRR: peak heat release rate, FPI: fire performance index, MLR: mass loss rate, THR: total heat release, * time after second flame application.

Figure 4. Cone calorimeter analysis: (a) HRR; (b) THR; (c) SPR; (d) carbon monoxide production (COP).

Figure 5. Digital photographs of CC char residues: (a) KeC; (b) KeC-IFR; (c) KeC-IFR+HNT; (d) KeC-IFR+MMT.

Figure 6. ESEM images of CC char residues of KeC-IFR (a and b), KeC-IFR+HNT (c and d) and KeC-IFR+MMT (e and f).

Figure 7. Mechanical properties of KeC-IFR composites: (a) modulus; (b) strength.

Figure 8. Morphological analysis of tensile-fractured samples: (a) KeC; (b) KeC-IFR; (c) KeC-IFR+HNT; (d) KeC-IFR+MMT.