Preparation, characterization and flame retardancy of phosphorus-containing poly-styrene-acrylate emulsion

Figures & data

Figure 1. Formation mechanism of P-containing monomer.

Figure 2. ¹H-NMR spectrum of P-monomer and respective hydrogen resonances (600 MHz, CDCl₃).

Table 1. Recipe of the prepared P-PSA emulsion.

Sample	St	BA	NMA	P-monomers
P0	60	38	2	0
P1	52	36	2	10
P2	44	34	2	20
P3	36	32	2	30
P4	28	30	2	40

Figure 3. FTIR spectra of PSA (a) and P-PSA (b) co-polymer.

Table 2. Effects of P-monomer content on the prepared P-PSA emulsion.

P- 1 monomer content (wt%)	Monomer conversion rate (wt%)	Coagulum content (wt%)	Ca^2+ stability	Centrifugal stability	Mechanical stability	Average particle size (nm)
0	98.1	0.35	√	√	√	115
10	97.2	0.13	√	√	√	107
20	96.7	<0.1	√	√	√	102
30	95.6	<0.1	√	√	√	98
40	93.5	<0.1	√	√	√	95

√ means no flocculation observed after stability test.

Figure 4. TEM images of emulsions with different P-monomer contents: (a) 0, (b) 10%, (c) 20%, (d) 30% and (e) 40%.

Figure 5. TGA of P-PSA co-polymers with various P-monomer contents.

Table 3. Effects of P-monomer content on flame retardancy of P-PSA co-polymers.

P-monomer content	LOI	UL-94
0	18.0 ± 0.2	– –
10	22.9 ± 0.3	HB
20	27.3 ± 0.3	V1
30	30.6 ± 0.3	V0
40	33.1 ± 0.2	V0

Figure 6. Morphology and components of char residue of P-PSA co-polymer: (a) exterior and (b) interior.

Table 4. Element composition of P-PSA (30 wt% P-monomer) resin content before and after burning.

Sample	C	P	O
Before burning	66.78	3.30	29.92
After burning	76.30	11.32	13.30

Figure 7. Energy spectrum before (a) and after (b) combustion of P-PSA co-polymer.