Synergistic Flame Retardant Effects of Expandable Graphite and Ammonium Polyphosphate in Water-Blow Polyurethane Foam

Table 4

Influence of EG/APP proportion on the performances of SPUF.

Samples	Ratio of EG/APP	Apparent density (kg/m³)	Shore’s hardness (HA)	Compression strength (MPa)	Modulus of compression (MPa)
SPUF	\	46.60 ± 0.76	55.64 ± 1.32	0.056 ± 0.002	0.75 ± 0.04
APP/SPUF	\	61.56 ± 0.97	64.77 ± 2.10	0.064 ± 0.004	1.25 ± 0.06
EG/SPUF	\	68.06 ± 1.43	58.82 ± 1.33	0.051 ± 0.001	0.59 ± 0.05
EG/APP/SPUF-2	1 : 4	59.60 ± 0.36	56.63 ± 1.12	0.053 ± 0.003	0.70 ± 0.04
EG/APP/SPUF-4	1 : 2	66.52 ± 1.02	59.54 ± 0.65	0.047 ± 0.002	0.45 ± 0.02
EG/APP/SPUF-8	2 : 1	61.88 ± 0.63	58.08 ± 0.53	0.044 ± 0.002	0.40 ± 0.02