Investigation Of Effects Of Two Flame Retardants On The Fire Characterisit Ics Of Flexible Poly Ether Foam

The rising time occurs when foam mix starts to rise until it gets to a full block height. At this stage the isocyanate reacts with water to generate carbon dioxide which causes the rise. The formation of the carbon dioxide through the intermediate carbamic acids gives.
RH = C = O + H – O – H    RNH COOH        RNH 2 + CO2
The curing time is the reaction process that leads to completion of the polymerization reaction that is usually greater than 15 hours. Polyurethane can either be flexible or rigid depending on the nature of the polymer and cross linking produced. In the production of flexible polyurethane foam, the polymerization reaction takes place between a difunctional polyol and tolu ne diisocyanate. Flexible polyurethane foams can be classified base on the density: low density, 16-24 kg/m2, medium density, 32-48kg/m3 and high density; 48kg/m3 and above [7].
The two basic types of flexible polyurethane foams are polyester and polyether flexible polyurethane foams. Polyesters are used mainly for clothing, interlining and packaging while polyether are used to produced mattresses, cushions and general upholstery [8]. Flexible polyurethane foams can be produced in many grades of flammability , elongation and load bearing capacities .
The level of flammability of the polyurethane foams is of great concern both to the foam industries as well as whole masses. In order to reduce the flammability of these polyurethane foams, and he reby reducing the destructive tendencies of fire outbreaks some suitable flame retardants are incorporated into the foam. This study aims at producing a flame retarded polyether flexible polyuretha ne foam of melamine and tri ammon ium orthophosphate in various formulations.
1.2    Significance of the Research.
Flexible polyurethane foams are used in several applications in homes, (mattresses, cushion s), industries (automobile, packaging etc); hence decrease in their flammability will save lots of life and properties in event of fire outbreak in these areas.
 
  Establishing the effects of using different concentration of the applied fire retardants to the flexible polyurethane foams will be valuable to commercial foam manufacturers and researchers in the polymer industry.
 Statistical establishment of the better fire retardants out of the two on the fire characteristics of flexible poly urethane foams will be useful to commercial foam manufacturers.
 Comparison of the f ire characteristics of flame retarded polyurethane foams with the existing commercial foams will clear the doubt of whether commercial manufacturers actually incorporate fire retardants o r not.

1.3    Scope of the Study
*    The study was based on only flexible polyether foams.
*    The flame retardants incorporated in various formulations are melamine , (C3H6N6) and tri- ammonium orthophosphate (NH  4)3.(P04.3H20).
*    The fire characteristic s that were tested include: flame propagation rate, ignition time, after glow time, % char formation, and flame duration.
1.4    The objective s of the Study;
*    The effects of melamine and triammonium orthophosphate on the fire characteristics of the flexible polyurethane foams were investigated.
*    The fire characteristics of flexible polyurethane that was flame retarded with melamine was compared with that of flame retarded with triammonium orthophosphate.
*    The reduction of the flammability of the flexible polyurethane foams was verified.
*    The extent of the effects of the two flame retardants on the ignition behaviour of flexible polyurethane foams was established.