Flame Retardant Additives
The term flame retardants refer to a diverse group of chemical additives.
18:31 01 March 2021
which are put into the manufactured materials like plastics as well as textiles and surface finishes along with coatings. The flame retardant additives get activated in the presence of an ignition source and are expected to prevent and slow down the further progression of flame by a variety of different physical as well as chemical methods. Thus it is a substance that is added as a substance in form of a treatment that is applied to a material to suppress or delay the appearance of a flame along with decreasing the flame-spread rate. This it reduces and slows down ignition as well as the significant reduction in the rate of combustion(“Flame Retardant - an overview | ScienceDirect Topics,” n.d.-b).
These additives are either added in form of copolymer during the polymerisation process or subsequently added to the polymer during the moulding and the extrusion process and applied as a topical finishing agent like a topical finish. Also, mineral flame retardants exist which are in form of additives whereas organohalogen as well as organophosphorus compounds. Also, improved flammability regulations demonstrate the global usage of organic brominated (Laoutid et al., 2009), chlorinated, as well as phosphate flame retardant additives.
HOW DOES FLAME RETARDANT ADDITIVE work
The chemical product influences the formation of organic char which is effective in insulating the polymer and provides it resistance from the heat by cutting down the oxygen source. Also, it lowers heat as well as flames along with the reduced smoke release. Also in some FRAs molybdates are precipitated on an inert core which is a coated core approach that makes and provides efficient use of the molybdate species. This helps in providing maximum surface area by use of ammonium octamolybdate (AOM) which is much cheaper than pure molybdate chemicals.
TYPES OF FLAME RETARDANT ADDITIVES
- Some flame retardant additives contain Aluminium Trihydrate and are widely used as a smoke suppressant because of their versatility as well as low cost. This mix of ATH in the flame retardant additives assures high-performance. It is an alternative to halogen-free flame retardant additives ATH is a more desirable flame retardant versus halogenated compounds because no toxic smoke is emitted. Also, these enable environmentally compatible protection along with less aggressive smoke diverse materials such as rubber s well as plastic products(Levinṭa, Vuluga, Teodorescu, &Corobea, 2019). This material works at approximately 428°F (220°C).
- Another class for flame retardant additives is Magnesium hydroxide as well as Magnesium Hydroxide which provides flame retardance same as ATH but dehydrates at 626°F (330°C).
- Also Brominated flame retardant additives exist which havebromine and are used in consumer goods such as electronics, furniture, building materials and are associated with endocrine disruption.
- The Polybrominated diphenyl ethers are another class of additives that do not chemically bind with the products in which they are added such as furniture, electronics and can be easily released from those products ultimately enter air and dust.
- Tetrabromobisphenol is majorly used in the making of computer circuit boards as well as electronics. In addition to this, it is used in some textiles and paper.
- Hexabromocyclododecane is used in polystyrene foam building materials.
- Organophosphate flame retardants are replacements for Polybrominated diphenyl ethers. These are used in thermoplastics as well as polyurethane foams with the use of organic phosphorus compounds existing in form of phosphates as well as phosphonates(Villamil et al., 2020). They also contain phosphorus-halogen compounds as well as blends of phosphorous with halogenated flame retardants such as Brominated flame retardant additives.
FEATURES OF FLAME RETARDANT ADDITIVES:
- These are added to the polymeric material via physical mixing but they themselves do not bind to the polymer chemically i.e. do not undergo any chemical reactions(Chemicals, 2000).
- These can be incorporated into the polymeric mixture during any stage of manufacturing and are more advantageous over Reactive Flame Retardants.
- Especially designed flame retardants are majorly non-toxic and are halogen-free and designed to be chemically inert.
- High-quality FRAs has low abrasiveness.
- Also, the arc, as well as track resistance flame retardant additives, are used in plastics and endure when exposed to electrical arcing, acid resistance, as well as smoke suppression.
- Majorly at high temperatures these flame retardant additives decompose endothermically releasing approximately 35percent of its weight as water vapour.
- The water vapour released by the decomposition dilutes combustion gases as well as toxic fumes.
- The flame retardant additives majorly act as a heat sink and retard pyrolysis along with a significant reduction in the burning rate.
Majorly nitrogen compounds are small whereas are a rapidly growing group in the case of flame retardants additives.
- These flame retardant additives in the focus of public interest and are environmentally friendly.
- Also, they have low toxicity and exist in the solid-state. Also in case of fire the there is no dioxin or halogen acids along with less smoke.
- In addition to this, the metallic hydroxide of flame retardant additives split off the water and their low activity requires high concentrations and thus there is a change in the mechanical properties of the matrix on which they are applied.
- Also, they do not interfere with the set of stabilizers that are added to plastic materials.
- Also, they are suitable for recycling materials recycling as they have high decomposition temperatures.
Also, the main applications of such flame retardant additives are melamine for polyurethane flexible foams, melamine phosphates in polyolefines, melamine cyanurate in nylons, melamine as well as melamine phosphates or dicyandiamide in intumescent paints, guanidine phosphates for textiles and guanidine sulfamate for wallpapers.
Q1: What are flame retardant additives?
Ans: These are additives that are not an inherent property of the materials and are added as are compounds that do not bind covalently to the polymer.
Q2: How are flame retardant additives used?
Ans: The flame retardant is added to the polymer by physical mixing.
Q3: What are the common types of flame retardant additives?
Ans: The popularly used elements: aluminium, nitrogen, phosphorus, chlorine, antimony, bromine, and in special designs carbon as well as magnesium and zinc.
Q4: Why to use flame retardants additives?
Ans: These are used as they are derived from elements that are relatively easy to manufacture.
Q5: How are flame retardants additives used?
Ans: They are used in solid in which they shield the polymer by forming a charred layer which ultimately provides protection to the polymer by cutting off oxygen and heat. But when used in the gaseous phase they remove the high energy radicals H as well as OH from the flame.