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Industrial Chemistry Project Topics

Investigation of Effects of Two Flame Retardants on the Fire Characterisit Ics of Flexible Poly Ether Foam

Investigation of Effects of Two Flame Retardants on the Fire Characterisit Ics of Flexible Poly Ether Foam

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Investigation of Effects of Two Flame Retardants on the Fire Characterisitics of Flexible Poly Ether Foam

CHAPTER ONE

The objectives of the Study;

  • The effects of melamine and tri ammoniumorthophosphate on the fire characteristics of the flexible polyurethane foams were
  • The fire characteristics ofย  flexibleย  polyurethaneย  that was flame retarded with melamine was compared with that of flame retarded with t ri ammon ium orthophosphate .
  • The reductionย  ofย ย  theย  flammability of the flexible polyurethane foams was
  • The extent of the effects of the two flame retardants on the ignition behaviour of flexibleย  polyurethaneย  foams was established .

CHAPTER TWO

LITERATURE REVIEW

Fire, Pyrolyses and Combustion

Fire is the reaction involving fuel and oxygen that produces heat and light . It results from rapid chemical reaction between a fuel (wood,ย  gasoline) orย  polymeric materials (plastic, cellulose) and oxygen. In order to produce fire a combustible materials and oxygen must be present and in contactย  at sufficient high temperature to initiate combustion. Th e two substances (oxygen and fuel) must continue to be in contact for combustion to be sustained.

A flame is a gas phase combustion reaction which is able to propagate through spaceย  [10]. Fire is a common term for combustion especially when out of control combustion refers to exothermic reaction inย  any phase.ย  It usuallyย ย ย ย ย ย  implies propagation and oxidation.ย  Inย  mostย  combustionย  processes the exothermic stages occur in the gasย  phaseย  regardlessย  of theย  initialย  phasesย  ofย  the ย reactants. ย Therefore , flames are associated with most combustionย ย ย ย ย  processes. The combustibilityย  ofย  aย ย  substanceย ย  dependsย  onย ย  itsย  chemical compositionย  and physical stateย ย ย ย  [3,10] . For instance, if the source of oxygen is air, then the molecules of any flammable gasย  escapingย  intoย  theย  air,ย  will mix withย ย  oxygen molecules and at ignition temperature,ย  willย  burn.ย  Inย  caseย  ofย  aย  liquid, the flammable liquid must first be vapourized and its vapour mixed with oxygen, and it will burn. Similarly, solids must usually be liquefiedย  andย  vapourized,ย  orย  at lease reduced to small particles, with large surface area before it will burn.

Everyย ย  materialย  mustย  beย ย  raisedย ย  toย ย  itsย ย ย  specific ignition temperature before a fire will occur, though oxidation of the material may take place below this temperature. Oxidation normallyย  involve s atmosphericย ย ย ย ย ย ย ย ย ย  oxygen,ย ย ย  but manyย  other oxidizers produce flames and some flames do not involves oxidation reactions. Above the ignition temperature, the heat of oxidation does not dissipate fast enough andย  raisesย  the next area of unburned fuel to ignition temperature. Normally the ignition temperature of solids are higher thanย  those of the liquids.

When a part of any material is exposed to external source of heat, its temperature will rise as a result of heat transfer. As temperature progressively increases, a point is reached when enough thermal energy has been imbibed as to break bonds.

 

CHAPTER THREE

EXPERIMENTAL

Materials and Methods

The materials include:

  1. Polyol
  2. Toluenediisocynate (TDI)
  3. Silicone
  4. Dimethylethanol amine
  5. Water
  6. Stanousoctate or Tin II
  7. Melamine
  8. Tri ammonium orthophosphate

Material (1 โ€“ 6) above were all obtained from Marthar foams industries Ltd., Nkpor โ€“ Obosi Road, Onitsha Anambra State Nigeria.

Melamine and tri ammonium orthophosphate were bought from Laboratory of National Research Institute for Chemical Technology (NARICT), Zaria .

Apparatus

Apparatus used for the experiment are:

  • Carbolite muffleย  furnace,ย  AAFย  11/ 18 serial No: 20โ€“ 501901

Methods

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Polyurethane foam formulations

Martharย  foams industries formulaย  for foam production was used forย  the foam recipe. The quantity of raw materials used in the production of polyurethane foam wereย  constant,ย  only the concentrationย  of flame retardants were varied.

CHAPTER FOUR

RESULTS AND DISCUSSION

After Glow Time (AGT)

The resultsย  of theย  after glow time produced with the twoย  flameย  retardants ย are ย shownย  inย ย  Table 6, 3 below . The incorporation of ย these twoย ย  flame retardants into theย  substrate substantially reduced AGT โ€“ as much as six โ€“ fold at 2.5pph melamine concentration. Glow is an exothermal oxidative combustion of material without a flame and is known to depend on quantity of carbonaceous char availableย ย  [47]. Thus, the higher the char, the longer the AGT values. ย In theย  Fig. 3 below, at all concentrations after glow is decreased with respect to untreated sample. The significance of this observation becomes clear if it is realized that in fire situation, what is most striking is the flame and that attracts fire combatants. There have been countless cases ย when after the flame ย have ย been dowsed and everybody gone home, and the fire starting all over later. This scenario is because ; theย ย  usually not perceptible glow wasย  notย  extinguished. Of causeย  , the longer theย  AGT time, the higher the risk ofย  re-enlightenment of a fire. Obviously therefore, reduction of AGT is a very useful technique in fire chemistry.

CHAPTER FIVE

CONCLUSION

The following conclusion can be made from the results of the study.

The two flame retardants, melamine ย and tri ammonium orthophosphate ,ย  were successfullyย  incorporated in the production of flexible polyurethane foams under the productionย  conditions of a commercial foam industry.

Hence, itย  isย  clearย  that the two flame retardants are ย suitable for producing commercial foams that are affordable and maintains the quality.

The two flame retardants are effective inย  reducing the after – glow time (AGT), flame duration time and propagation rate properties . The reduction of these fire char5acterisitcis is paramountย  to reductionย  ofย  flammability of the polyurethane foam which leads to safety of lives and properties.

Dramatic increase in ignition time and charring percentage shown by t ri ammonium orthophosphate is evidence that its incorporation into polyurethane will delay burning on occasions of fire, t hereby increases time for safety of life and properties.

However,ย  melamine showed better impact for after-glow time and flame duration time, while triammoniumorthophosphate is preferredย  forย  reductionย  ofย  ignitionย  time andย  propagation rate due to ย increase in high percentage charring.

RECOMMENDATION

  1. The two flame retardants are recommended for use for retarding commercial polyurethane foams, that will reduce the incident of fire and destruction of life and
  2. Tri ammonium ortho phosphate is preferred for retarding flexible polyurethane foams to
  3. The commercial foam industries that are not incorporating any flame retardants to their products, because of cost, can now start to make use of these two flame retardants becauseย  of ย its ย availability and low

REFERENCES

  • National Fire Protection Association (2008) fire loss in US duringย  2005,ย ย  abridg edย ย  reportย  ( http:/ / usfa. gov/ statistic / National) ( Retrieved, February 28, 2010)
  • M. Avento, (1980), Flame Retardant , an Overview. Encyclop aedia of Chemical Technology Vol. 10, John Wiley & Sons. New York , pp 348 โ€“ 372.
  • N. Eboatu (1992) Fire, Flammabilityย  and Fire Fighting . Anchor Ednal Press, ย Lagos, p.25
  • Nguyen ย Huyย  (2008)ย  โ€œFlame Reta rdantsโ€ Microsoft Studentย  (DVD), Redmond: WA: Microsoft Corporation 2007
  • Gum;ย  W. ย Riese; and H. Ulrich, (1992), Reaction Polymers; Oxford University Press , New York, pp . 108 – 112.
  • Ulrich (1996) Chemistryย  and Technology of Isocyanates;ย  John Wiley &ย  Sons ICN, New York, pp. 98โ€“ 100.

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