Effect of Metal Oxides on Fire Resistance and Char Formation of Intumescent Flame Retardant Coating

doi:10.15541/jim20130686

Abstract

Abstract:

Metal oxides (MO) can remarkably affect the char formation of intumescent flame retardants (IFR) during thermal decomposition, thereby improving the fire resistance property of IFR coatings. In present work, Fe₂O₃, ZnO and TiO₂ were separately incorporated with caged bicyclic phosphates based IFR in epoxy coating, and their effects on fire resistance and char formation of the IFR coating were investigated. Back temperature test results showed that MO worked synergistically on improving fire resistance of the coating and their effectiveness of improvement followed the trend of Fe₂O₃>ZnO>TiO₂. Thermogravimetric analysis (TGA), laser Raman spectroscopy (LRS) and X-ray photoelectron spectroscopy (XPS) results revealed that MO promoted the formation of pseudo-graphic char with improved thermal stability which still survived at high temperature, and their effectiveness of promotion also followed the trend of Fe₂O₃>ZnO>TiO₂.

Key words: metal oxides, caged bicyclic phosphates, intumescent flame retardancy, epoxy coating

CLC Number:

TQ132

ZHOU You, LIU Xiu, WANG Fang, HAO Jian-Wei, DU Jian-Xin. Effect of Metal Oxides on Fire Resistance and Char Formation of Intumescent Flame Retardant Coating[J]. Journal of Inorganic Materials, 2014, 29(9): 972-978.

Figures/Tables 11

References 33

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No.	Sample	Fire resistance time/s	V_300℃^a/(℃•s^-1)	V_400℃/(℃•s^-1)
		t_300℃	t_400℃
1	EP/T-IFR	200	1040	1.50	0.38
2	EP/T-IFR/2.3wt% Fe₂O₃	230	2200	1.30	0.18
3	EP/T-IFR/3.5wt% Fe₂O₃	280	2360	1.07	0.17
4	EP/T-IFR/4.5wt% Fe₂O₃	220	2010	1.36	0.20
5	EP/T-IFR/2.3wt% ZnO	320	1780	0.94	0.22
6	EP/T-IFR/3.5wt% ZnO	340	2140	0.88	0.19
7	EP/T-IFR/4.5wt% ZnO	530	1710	0.57	0.23
8	EP/T-IFR/2.3wt% TiO₂	220	1440	1.36	0.28
9	EP/T-IFR/3.5wt% TiO₂	260	1520	1.15	0.26
10	EP/T-IFR/4.5wt% TiO₂	240	1380	1.25	0.29

No.	Sample	Fire resistance time/s	V_300℃^a/(℃•s^-1)	V_400℃/(℃•s^-1)
		t_300℃	t_400℃
1	EP/T-IFR	200	1040	1.50	0.38
2	EP/T-IFR/2.3wt% Fe₂O₃	230	2200	1.30	0.18
3	EP/T-IFR/3.5wt% Fe₂O₃	280	2360	1.07	0.17
4	EP/T-IFR/4.5wt% Fe₂O₃	220	2010	1.36	0.20
5	EP/T-IFR/2.3wt% ZnO	320	1780	0.94	0.22
6	EP/T-IFR/3.5wt% ZnO	340	2140	0.88	0.19
7	EP/T-IFR/4.5wt% ZnO	530	1710	0.57	0.23
8	EP/T-IFR/2.3wt% TiO₂	220	1440	1.36	0.28
9	EP/T-IFR/3.5wt% TiO₂	260	1520	1.15	0.26
10	EP/T-IFR/4.5wt% TiO₂	240	1380	1.25	0.29

Sample	T_i /℃	△T_i /℃	CR_300℃ /%	△CR^b_300℃/%	CR_700℃ /%	△CR_700℃/%
Sample	Calcd./Exp.	△T_i /℃	Calcd./Exp.	△CR^b_300℃/%	Calcd./Exp.	△CR_700℃/%
EP/T-IFR	-/238	-	-/86	-	-/27	-
EP/T-IFR/3.5wt% Fe₂O₃	242/271	29	87/91	4	29/39	10
EP/T-IFR/3.5wt%ZnO	242/270	28	87/93	6	29/36	7
EP/T-IFR/3.5wt% TiO₂	242/268	26	87/89	2	29/32	3

Sample	T_i /℃	△T_i /℃	CR_300℃ /%	△CR^b_300℃/%	CR_700℃ /%	△CR_700℃/%
Sample	Calcd./Exp.	△T_i /℃	Calcd./Exp.	△CR^b_300℃/%	Calcd./Exp.	△CR_700℃/%
EP/T-IFR	-/238	-	-/86	-	-/27	-
EP/T-IFR/3.5wt% Fe₂O₃	242/271	29	87/91	4	29/39	10
EP/T-IFR/3.5wt%ZnO	242/270	28	87/93	6	29/36	7
EP/T-IFR/3.5wt% TiO₂	242/268	26	87/89	2	29/32	3

Sample	T_i /℃	△T_i /℃	CR_700℃ /%	△CR_700℃/%
Sample	Calcd./Exp.	△T_i /℃	Calcd./Exp.	△CR_700℃/%
EP	-/123	-	-/5.7	-
EP/5wt%Fe₂O₃	125/183	58	10.4/15.9	5.5
EP/5wt%ZnO	125/186	61	10.4/18.7	8.3
EP/5wt%TiO₂	125/172	47	10.4/12.6	2.2