TABLE OF CONTENTS Polyurethanes (PU) are polymers which, in a fire, burn totally. During the not very long history of PU, intensive research efforts were made to produce fire resistant PU.
Unfortunately, many human lives were lost and many valuable buildings, constructions and materials were totally destroyed due to the high combustibility of polymers, PU included.
The development of fire resistant polymers is dictated by the necessity for the safety, security and protection characteristic of modern life. The fire retardancy of polymers not only has a scientific implication, but also social (protection of human lives), political (obligation of utilisation of flame retardant polymers in specific fields which present danger for human lives in the accidental fire such as: construction, furniture, automotive, and so on), economic (protection of buldings and other valuable materials), military (protection of military equipment) and ecological implications (limitation of toxic and corrosive gases evolved during burning, limitation of the level of smoke generation during burning).
Fire resistant PU are obtained by the addition or by introduction into the PU structure of special compounds, called flame retardants. The flame retardants are organic compounds containing halogens (chlorine, bromine) and phosphorus. Compounds of antimony (Sb) or boron [1-13] are rarely used. Sometimes inorganic compounds are used as flame retardants for PU, such as, hydrated alumina (Al 2O 3*nH 2O), Sb 2O 3 or ammonium polyphosphate [1-3, 14].
Halogenated organic compounds act in the flame, by blocking the chain reactions which are...
