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Effect of expandable graphite particle size on the flame retardant, mechanical, and thermal properties of water‐blown semi‐rigid polyurethane foam
Author(s) -
Li Yi,
Zou Jing,
Zhou Shengtai,
Chen Yang,
Zou Huawei,
Liang Mei,
Luo Wenzhou
Publication year - 2014
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.39885
Subject(s) - fire retardant , materials science , particle size , limiting oxygen index , composite material , thermogravimetric analysis , polyurethane , thermal stability , graphite , particle (ecology) , composite number , chemical engineering , pyrolysis , char , oceanography , engineering , geology
Different particle size of expandable graphite (EG) were incorporated into water‐blown semi‐rigid polyurethane foams (SPFs), which acted as the fire shield, in order to enhance the fire retardant properties. In this study, the particle size of EG was systematically varied from 70 µm to 960 µm. The effect of EG particle size on the density, mechanical properties, and thermal stability of SPFs was also investigated. Results showed that EG with smaller particle size showed almost no effect on the fire retardant properties of SPFs while the larger particle size of EG could effectively enhance it. It was observed that the flame retardancy of the composite improved with the increase of EG size which was attribute to the formation and densification of isolation layer with the increase in volume of expanded graphite. Limiting oxygen index (LOI) value of EG/SPF composites increased linearly by two steps with the increase in EG particle size. Horizontal burning test confirmed the above conclusion. Thermogravimetric analysis (TGA) indicated that EG particles and its size exhibited minor effect on the thermal stability of the SPF composites. Moreover, SPF filled with medium particle size of EG (about 400 µm) exhibited a poor compression performance compared with the others. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 39885.