MELAMINE
Melamine is an organic compound that is often combined with formaldehyde to produce melamine resin, a synthetic polymer that is fire resistant and heat tolerant.
The resin is a versatile material that has a highly stable structure. Its uses include whiteboards, floor tiles, kitchenware, fire retardant fabrics and commercial filters.
Melamine can be easily molded while warm but will set into a fixed form, which makes it suitable for certain industrial applications.
This compound is considered safe for its normal uses, but food products that are contaminated with it can be unsafe for consumption.
EC / List no.: 203-615-4
CAS no.: 108-78-1
Mol. formula: C3H6N6
2,4,6-triamino-1,3,5-triazine
Melamine
Melamine
melamine
CAS names
1,3,5-Triazine-2,4,6-triamine
IUPAC names
1,3,5 – triazine – 2,4,6 – triamine
1,3,5-Triazine-2,4,6-triamine
1,3,5-triazine-2,4,6-triamine
1,3,5-triazine-2,4,6-triamine.
1,3,5-triazine-2,4,6-triazine
2,4,6-Triamino-1,3,5-triazin
2,4,6-triamino-1,3,5-triazina
2,4,6-TRIAMINO-1,3,5-TRIAZINE
2,4,6-triammino-1,3,5-triazina
Melamine
melamine
Melamine
melamine
Melamine Monomer
Trade names
1,3,5-Triazine-2,4,6(1H,3H,5H)-triimine
1,3,5-triazine-2,4,6(1H,3H,5H)-triimine
1,3,5-Triazine-2,4,6-triamine (9CI)
2,4,6-s-triazinetriamine
2,4,6-Triamino-1,3,5-triazine
2,4,6-Triamino-s-triazine
2,4,6-Triaminotriazine
Cyanuramide
Cyanurotriamide
Cyanurotriamine
Isomelamine
Melamin
Melamine
melamine
Melamine (8CI)
s-Triazine, 4,6-diamino-1,2-dihydro-2-imino- (6CI)
s-Triazinetriamine
technical melamine
To be identified
Triamino-s-triazine
Triaminotriazine
Melamine is chemical substance rich in nitrogen, inexpensive and widely available as it is used in the manufacture of many laminates, plastics, coatings, glues, and kitchenware.
Mostly melamine is used in the wood-based panel industry, but there is a wide range of other application fields.
Melamine (MEL) is a chemical that has been used for many purposes other than the original coatings, filters, adhesives, and tableware.
Melamine can be used in Melamine Based Superplasticizer-powder production.
Melamine Based Superplasticizer is a melamine based high performance superplasticizer and high range water reducer for cement and gypsum based products to plisticize hydrolitic mortars or to increase the compresive strenght.
Melamine formaldehyde sulfonate resin ( superplasticizer ) is also used in order to improve and promote quality of concrete with a retarding property even at tropical regions.
Melamine is an organic compound with the formula C3H6N6.
Melamine is white solid and it is a trimer of cyanamide, with a 1,3,5-triazine skeleton.
Like cyanamide, melamine contains 67% nitrogen by mass, and its derivatives have fire retardant properties due to its release of nitrogen gas when burned or charred.
Melamine can be combined with formaldehyde and other agents to produce melamine resins.
Such resins are characteristically durable thermosetting plastic used in high pressure decorative laminates such as Formica, melamine dinnerware, laminate flooring, and dry erase boards.
Melamine foam is used as insulation, soundproofing material and in polymeric cleaning products, such as Magic Eraser.
Melamine is a chemical compound with a number of uses, including manufacturing laminates, glues, dinnerware, and more.
This hard plastic can also be made in a wide range of colors and styles, making it an extremely versatile product that can be used in a variety of settings.
It is created by combining melamine resin with strengthening materials, which means it can stand up to the rigors of everyday use.
Melamine is converted from the raw material urea and consists of carbon, hydrogen and nitrogen.
Melamine has become an essential raw material in the global production of synthetic resins
Melamine is the most valuable and sophisticated product in the nitrogen chain.
Normally processed as a resin, this chemical compound is prized for the numerous exceptio
Melamine is an organic-based, nitrogen-rich compound used to manufacture cooking utensils, plates, plastic products, and more.
Melamine resin is durable, fire and heat resistant and virtually unbreakable, making melamine products more desirable than other plastic housewares.
Melamine, also called cyanuramide or triaminotriazine, a colourless crystalline substance belonging to the family of heterocyclic organic compounds, which are used principally as a starting material for the manufacture of synthetic resins. Melamine is rich in nitrogen, a property that is similar to protein.
nal qualities which make it so valuable in the production of articles used in everyday life.
Melamine resins deliver:
High stability, allowing end products containing melamine to resist high temperature exposure as well as physical and chemical degradation
High bonding potential, enabling surface applications with excellent properties like hardness as well as scratch and moisture resistance
High nitrogen content, making melamine an ideal flame retardant material
Most of the melamine produced worldwide is used by the wood-based panel industry.
Melamine is also commonly used in the construction, automotive and furniture industries.
Important applications include:
Laminates – laminate flooring, kitchen and bathroom countertops, self-assembly furniture, exterior wall claddings
Wood panels – plywood, particle boards, medium-density fibreboard (MDF), oriented strand board (OSB), laminated veneer lumber (LVL)
Coatings – vehicle body panels, household appliances, food and beverage cans, metal sheeting coils
Moulding compounds – tableware, electrical equipment, handles for pans, utensils
Flame retardants – upholstery, mattresses, fire-door coating
Resins for textile and paper finishing, including banknotes, wallpapers, wrinkle-free apparel
Concrete plasticisers
Preferred IUPAC name: 1,3,5-Triazine-2,4,6-triamine
Other names:
2,4,6-Triamino-s-triazine
Cyanurotriamide
Cyanurotriamine
Cyanuramide
CAS Number: 108-78-1
Melamine is sometimes illegally added to food products in order to increase the apparent protein content.
Ingestion of melamine may lead to reproductive damage, or bladder or kidney stones, and bladder cancer.
Melamine is also an irritant when inhaled or in contact with the skin or eyes.
The United Nations’ food standards body, the Codex Alimentarius Commission, has set the maximum amount of melamine allowed in powdered infant formula to 1 mg/kg and the amount of the chemical allowed in other foods and animal feed to 2.5 mg/kg.
While not legally binding, the levels allow countries to ban importation of products with excessive levels of melamine.
Chemical formula: C3H6N6
Molar mass: 126.123 g·mol−1
Appearance: White solid
Density: 1.573 g/cm3
Melting point: 343 °C (649 °F; 616 K) (decomposition)
Boiling point: Sublimes
Solubility in water: 3240 mg/ L (20 °C)
Solubility: very slightly soluble in hot alcohol , benzene, glycerol, pyridine
insoluble in ether, benzene, CCl4
log P: −1.37
Acidity (pKa): 5.0 (conjugated acid)
Basicity (pKb): 9.0
Magnetic susceptibility (χ): −61.8·10−6 cm3/mol
Refractive index (nD): 1.872
Structure
Crystal structure: Monoclinic
Thermochemistry
Std enthalpy of combustion (ΔcH⦵298): −1967 kJ/mol
Hazards
Autoignition
temperature > 500 °C (932 °F; 773 K)
Lethal dose or concentration (LD, LC):
LD50 (median dose) 3850 mg/kg (rat, oral)
Resin
This type of resin is made by mixing melamine with formaldehyde, and sometimes urea, under heat and pressure.
The substances begin to polymerize, and are forced into a mold to create the desired shape.
Under pressure, melamine releases water, which could make the plastic unstable if it is not removed.
The materials finish polymerizing and create a finished product
Melamine resin is known as a thermoset plastic because it is fixed after molding.
If exposed to enough heat, it will decompose. For this reason, this type of dishware should not be exposed to high temperatures such as those in an oven or microwave.
This type of resin also is difficult to recycle.
Foam
Foam products also can be made out of melamine.
This foam has a distinctive structure composed of stacked bubble shapes that are extremely hard and therefore can easily clean a wide variety of substances.
Melamine foam is marketed under a variety of commercial names, including several sponge-like products that are known for removing scuffs and dirt from a wide range of surfaces.
Heat Resistance
Melamine also plays a role in a wide range of flame-resistant materials.
These include textiles that are used in upholstery and the uniforms worn by firemen.
Thermal liners and heat-resistant gloves and aprons also are made using melamine.
Filters
Some filters also are made out of melamine. The material is porous and will admit substances to pass through but can be used to filter out particles of a particular size.
These filters are capable of handling a high capacity, can be used in hot environments and are extremely efficient.
Etymology
The German word Melamin was coined by combining the words Melam (a derivative of ammonium thiocyanate) and amine.
Melamine is, therefore, unrelated etymologically to the root melas (μελας, meaning “black” in Greek), from which the words melanin, a pigment, and melatonin, a hormone, are formed.
Uses
In one large-scale application, melamine is combined with formaldehyde and other agents to produce melamine resins. Such resins are characteristically durable thermosetting plastic used in high-pressure decorative laminates such as Formica, melamine dinnerware, laminate flooring, and dry erase boards.[7]
Melamine foam is used as insulation, soundproofing material and in polymeric cleaning products, such as Magic Eraser.
Melamine is one of the major components in Pigment Yellow 150, a colorant in inks and plastics.
Melamine also enters the fabrication of melamine polysulfonate, used as a superplasticizer for making high-resistance concrete.
Sulfonated melamine formaldehyde (SMF) is a polymer used as a cement admixture to reduce the water content in concrete while increasing the fluidity and the workability of the mix during handling and pouring. It results in concrete with a lower porosity and a higher mechanical strength, exhibiting an improved resistance to aggressive environments and a longer lifetime.
The use of melamine as fertilizer for crops had been envisioned during the 1950s and 1960s because of its high nitrogen content (2/3).
However, melamine is much more expensive to produce than are other common nitrogen fertilizers, such as urea. The mineralization (degradation to ammonia) for melamine is slow, making this product both economically and scientifically impractical for use as a fertilizer.
Melamine dinnerware
Melamine and its salts are used as fire-retardant additives in paints, plastics, and paper.
A melamine fibre, Basofil, has low thermal conductivity, excellent flame resistance and is self-extinguishing; this makes it useful for flame-resistant protective clothing, either alone or as a blend with other fibres.[10]
Melamine derivatives of arsenical drugs are potentially important in the treatment of African trypanosomiasis.
Melamine use as non-protein nitrogen (NPN) for cattle was described in a 1958 patent.
In 1978, however, a study concluded that melamine “may not be an acceptable non-protein N source for ruminants” because its hydrolysis in cattle is slower and less complete than other nitrogen sources such as cottonseed meal and urea.[13]
Melamine is sometimes illegally added to food products in order to increase the apparent protein content. Standard tests, such as the Kjeldahl and Dumas tests, estimate protein levels by measuring the nitrogen content, so they can be misled by adding nitrogen-rich compounds such as melamine. There are instruments available today which can differentiate melamine nitrogen from protein nitrogen.[14]
Toxicity
The short-term lethal dose of melamine is on a par with common table salt, with an LD50 of more than 3 grams per kilogram of bodyweight.
U.S. Food and Drug Administration (FDA) scientists explained that when melamine and cyanuric acid are absorbed into the bloodstream, they concentrate and interact in the urine-filled renal tubules, then crystallize and form large numbers of round, yellow crystals, which in turn block and damage the renal cells that line the tubes, causing the kidneys to malfunction.[16]
The European Union set a standard for acceptable human consumption (tolerable daily intake or TDI) of melamine at 0.2 mg per kilogram of body mass, (previously 0.5 mg/kg), Canada declared a limit of 0.35 mg/kg, and the US FDA’s limit was put at 0.063 mg/kg (previously 0.63 mg/kg). The World Health Organization’s food safety director estimated that the amount of melamine a person could stand per day without incurring a bigger health risk, the TDI, was 0.2 mg per kilogram of body mass.[18]
Toxicity of melamine can be mediated by intestinal microbiota.
In culture, Klebsiella terrigena, which rarely colonizes mammalian intestines, was shown to convert melamine to cyanuric acid directly.
Rats colonized by K. terrigena showed greater melamine-induced kidney damage compared to those not colonized.
Acute toxicity
Melamine is reported to have an oral median lethal dose (LD50) of 3248 mg/kg based on rat data. It is also an irritant when inhaled or in contact with the skin or eyes. The reported dermal LD50 is >1000 mg/kg for rabbits. A study by Soviet researchers in the 1980s suggested that melamine cyanurate, commonly used as a fire retardant,[21] could be more toxic than either melamine or cyanuric acid alone.[22] For rats and mice, the reported LD50 for melamine cyanurate was 4.1 g/kg (given inside the stomach) and 3.5 g/kg (via inhalation), compared to 6.0 and 4.3 g/kg for melamine and 7.7 and 3.4 g/kg for cyanuric acid respectively.
A toxicology study in animals conducted after recalls of contaminated pet food concluded that the combination of melamine and cyanuric acid in diet does lead to acute kidney injury in cats.[23] A 2008 study produced similar experimental results in rats and characterized the melamine and cyanuric acid in contaminated pet food from the 2007 outbreak.[24] A 2010 study from Lanzhou University attributed kidney failure in humans to uric acid stone accumulation after ingestion of melamine resulting in a rapid aggregation of metabolites such as cyanuric acid diamide (ammeline) and cyanuric acid.[25] A 2013 study demonstrated that melamine can be metabolized to cyanuric acid by gut bacteria. In particular, Klebsiella terrigena was determined to be a factor in melamine toxicity. In culture, K. terrigena was shown to convert melamine to cyanuric acid directly. Cyanuric acid was detected in the kidneys of rats administered melamine alone, and the concentration after Klebsiella colonization was increased.[20]
Chronic toxicity
Ingestion of melamine may lead to reproductive damage, or bladder or kidney stones, which can lead to bladder cancer.
A study in 1953 reported that dogs fed 3% melamine for a year had the following changes in their urine: reduced specific gravity, increased output, (3) melamine crystalluria, and (4) protein and occult blood.[30]
A survey commissioned by the American Association of Veterinary Laboratory Diagnosticians suggested that crystals formed in the kidneys when melamine combined with cyanuric acid, “don’t dissolve easily. They go away slowly, if at all, so there is the potential for chronic toxicity.”[31][32][33]
Metabolism
Melamine is a metabolite of cyromazine, a pesticide.
It has been reported that cyromazine can also be converted to melamine in plants.[35][36]
Treatment of urolithiasis
Fast diagnosis and treatment of acute obstructive urolithiasis may prevent the development of acute kidney failure. Urine alkalinization and stone liberalization have been reported to be the most effective treatments in humans.[25]
Regulation in food and feed
The United Nations’ food standards body, Codex Alimentarius Commission, has set the maximum amount of melamine allowed in powdered infant formula to 1 mg/kg and the amount of the chemical allowed in other foods and animal feed to 2.5 mg/kg. While not legally binding, the levels allow countries to ban importation of products with excessive levels of melamine.[37]
Synthesis and reactions
Melamine was first synthesized by the German chemist Justus von Liebig in 1834.
In early production, first calcium cyanamide was converted into dicyandiamide, which was heated above its melting temperature to produce melamine.
Today most industrial manufacturers use urea in the following reaction to produce melamine:
6 (NH2)2CO → C3H6N6 + 6 NH3 + 3 CO2
In the first step, urea decomposes into cyanic acid and ammonia:
(NH2)2CO → HNCO + NH3
Cyanic acid polymerizes to cyanuric acid, which condenses with the liberated ammonia forming melamine. The released water reacts with cyanic acid, which helps to drive the reaction:
6 HNCO + 3 NH3 → C3H6N6 + 3 CO2 + 3NH3
The above reaction can be carried out by either of two methods: catalyzed gas-phase production or high pressure liquid-phase production. In one method, molten urea is introduced onto a fluidized bed with catalyst for reaction. Hot ammonia gas is also present to fluidize the bed and inhibit deammonization. The effluent then is cooled. Ammonia and carbon dioxide in the off-gas are separated from the melamine-containing slurry. The slurry is further concentrated and crystallized to yield melamine.[38] Major manufacturers and licensors such as Orascom Construction Industries, BASF, and Eurotecnica have developed some proprietary methods.
The off-gas contains large amounts of ammonia. Therefore, melamine production is often integrated into urea production, which uses ammonia as feedstock.
Crystallization and washing of melamine generates a considerable amount of waste water, which may be concentrated into a solid (1.5–5% of the weight) for easier disposal.
The solid may contain approximately 70% melamine, 23% oxytriazines (ammeline, ammelide, and cyanuric acid), 0.7% polycondensates (melem, melam, and melon).
In the Eurotecnica process, however, there is no solid waste and the contaminants are decomposed to ammonia and carbon dioxide and sent as off gas to the upstream urea plant; accordingly, the waste water can be recycled to the melamine plant itself or used as clean cooling water make-up.
Melamine reacts with acid and related compounds to form melamine cyanurate and related crystal structures, which have been implicated as contaminants or biomarkers in Chinese protein adulterations.
Drug derivatives
Melamine is part of the core structure for a number of drugs including almitrine, altretamine, cyromazine, ethylhexyl triazone, iscotrizinol, meladrazine, melarsomine, melarsoprol, tretamine, trinitrotriazine, and others.
Production in mainland China
Between the late 1990s and early 2000s, both consumption and production of melamine grew considerably in mainland China.
By early 2006, melamine production in mainland China is reported to be in “serious surplus”.
Between 2002 and 2007, while the global melamine price remained stable, a steep increase in the price of urea (feedstock for melamine) has reduced the profitability of melamine manufacturing.
Currently, China is the world’s largest exporter of melamine, while its domestic consumption still grows by 10% per year.
However, reduced profit has already caused other joint melamine ventures to be postponed there.
Melamine can be manufactured from dicyandiamide, hydrogen cyanide, or urea.
Modern commercial production of melamine typically employs urea as a starting material. Urea is broken down to cyanuric acid, which then can be reacted to form melamine.
Its most important reaction is that with formaldehyde, forming melamine-formaldehyde resins of high molecular weight.
These compounds form under the influence of heat and then become fixed into an insoluble and infusible mold; this process is known as thermosetting.
Melamine-based thermoset materials contain cross-linked polymers, which make the fixed molds strong and durable.
Usually formulated with fillers and pigments, melamine resins can be molded into dishes, containers, utensils, handles, and the like or used as laminating agents or coating materials for wood, paper, and textiles.
Formica and Melmac are well-known trade names for products based on melamine resins.
Melamine has also been incorporated into a variety of flame-retardant materials.
This application is based on the compound’s high nitrogen content.
When exposed to heat, melamine degrades and releases nitrogen.
The freed nitrogen takes the place of oxygen in the surface air surrounding the material, which prevents the material from burning.
Butylated melamine resins, made by incorporating butyl alcohol into the melamine–formaldehyde reaction mixture, are fluids used as ingredients of paints and varnishes.
A copolymer containing melamine, formaldehyde, and sodium bisulfite produces a foam with sound-absorbing and flame-retardant properties.
The foam has a notably hard microbubble structure, which gives it an abrasive quality that has been utilized in the development of cleaning products
MELAMINE
1,3,5-Triazine-2,4,6-triamine
108-78-1
Cyanurotriamide
Cyanuramide
Cyanurotriamine
Isomelamine
Theoharn
Teoharn
Triaminotriazine
Cyanuric triamide
Hicophor PR
s-Triazinetriamine
Aero
2,4,6-Triamino-1,3,5-triazine
Yukamelamine
Pluragard
Cymel
Virset 656-4
2,4,6-Triamino-s-triazine
Spinflam ML 94M
2,4,6-Triaminotriazine
Pluragard C 133
ADK Stab ZS 27
Mark ZS 27
DG 002 (amine)
Melamine Monomer
NCI-C50715
Cyanurtriamide
s-Triazine, 2,4,6-triamino-
1,3,5-Triazine-2,4,6(1H,3H,5H)-triimine
ZS 27
UNII-N3GP2YSD88
NSC 2130
DG 002
sym-Triaminotriazine
Melamine, 99%
N3GP2YSD88
DTXSID6020802
CHEBI:27915
Melamine-d6
MFCD00006055
melamin
s-triaminotriazine
CCRIS 373
HSDB 2648
EINECS 203-615-4
BRN 0124341
2,4,6-triamino sym-triazine
AI3-14883
AX2
2,6-Triaminotriazine
CYMEL (Salt/Mix)
Metformin EP impurity D
2,4,6-Triamino-1,3,5-triazine Monomer
DSSTox_CID_802
2,6-Triamino-s-triazine
Melamine-13C3,15N3
1,3,5-triazine-2,4,6(1H,3H,5H)triimine
EC 203-615-4
s-Triazine,4,6-triamino-
DSSTox_RID_75795
DSSTox_GSID_20802
SCHEMBL25853
Melamine, analytical standard
4-26-00-01253 (Beilstein Handbook Reference)
BIDD:ER0287
CHEMBL1231106
SCHEMBL12192199
Melamine (Metformin Impurity D)
1,5-Triazine-2,4,6-triamine
2,6-Triamino-1,3,5-triazine
NSC2130
NSC8152
Melamine 100 microg/mL in Water
ZINC897751
HY-Y1117
NSC-2130
NSC-8152
WLN: T6N CN ENJ BZ DZ FZ
Tox21_200503
1,3,5-triazinane-2,4,6-triimine
BBL000010
s9212
SBB000053
STK378738
[1,3,5]triazine-2,4,6-triamine
1,3, 5-Triazine-2,4,6-triamine
2,4, 6-Triamino-1,3,5-triazine
AKOS005448714
CCG-266105
MCULE-1467355510
NCGC00164014-01
NCGC00164014-02
NCGC00258057-01
1246816-14-7
2,4,6-triamino-1,3,5-triazine;melamine;1,3,5-triazine-2,4,6-triamine;[1,3,5]triazine-2,4,6-triamine;s-triazine, 4,6-diamino-1,2-dihydro-2-imino-;2,4,6-triamino-1,3,5-triazine melamine 1,3,5-triazine-2,4,6-triamine [1,3,5]triazine-2,4,6-triamine s-triazine, 4,6-diamino-1,2-dihydro-2-imino-
CAS-108-78-1
ST018511
VS-00405
1,3,5-Triazine-2,4,6-triamine monomer
Melamine 1.0 mg/ml in Dimethyl Sulfoxide
CS-0016866
FT-0609833
FT-0670982
FT-0670983
Melamine; 1,3,5-Triazine-2,4,6-triamine
T6897
1,3,5-Triazine-2,4,6-triamine (Melamine)
1,5-Triazine-2,4,6(1H,3H,5H)-triimine
Melamine 100 microg/mL in Acetonitrile/Water
1,3,5-Triazine-2,4,6-triamine, homopolymer
4,6-Diamino-1,2-dihydro-2-imino-S-Triazine
s-Triazine, 4,6-diamino-1,2-dihydro-2-imino-
Q212553
J-002191
1,3,5-Triazine-2,4,6-triamine (ACD/Name 4.0)
Melamine, >=95.0% (HPLC), pharmaceutical impurity standard
Melamine, United States Pharmacopeia (USP) Reference Standard
N,N’,N”-Tri-2-pyridinyl-1,3,5-triazine-2,4,6-triamine
Melamine, Pharmaceutical Secondary Standard; Certified Reference Material
25778-04-5
5432-64-4
Application of Melamine Sulfonate powder:
Melamine Based Superplasticizer should be added to the cement concrete mix or gypsum with the other dry ingredients just before processing and after good mixing.
Application areas:
Grout, plaster, tile adhesive products
Plasterboards, blocks and molding plasters from gypsum
Ready Mixed Concrete
Precast production
Self leveling applications,
Advantages:
Improves finishing quality and workability.
Impoves ultimate machanical strenght
Reduces water requirement
Reduces segregation
Reduces cracking and permeability
High-Range Water Reducing / Superplasticizing / Set Accelerating Raw material for Concrete Admixtures.
Melamine Sulfonate based raw material designed for high water reducing and early strength enhancement in concrete admixture formulations as raw material.
Use
Melamine Sulfonate is used in the following conditions and applications:
In cold climate concreting.
In the production of prestressed concrete with low water / cement ratio,
In precast and prefabricated concrete production,
Where early demolding is desired
Reoplastic concretes which can easily be placed on dense reinforced concrete elements.
It is suitable for use in concrete structural elements produced with zero slump.
Advantages and Properties
The early and final strength of the admixture formulated with Melamine Sulfonate is increased compared to unleaded concrete.
Increases compressive and flexural strength of Melamine Sulfonate-formulated additive compared to concrete without admixture
Early high-strength concrete production is achieved even at low temperatures.
Shorten the mold removal time.
Increases the abrasion resistance of concrete by reducing segregation and bleeding.
Increases durability of concrete against freeze-thaw cycle.
Improves concrete’s mechanical properties such as impermeability, durability, shrinkage and creep.
Saves energy in heat curing of concrete. Concrete could be placed with less vibration even in dense reinforced concrete structures.
Sulfonated Melamine Formaldehyde,also name as Melamine sulfonate formaldehyde condensate,or melamine formaldehyde sulfonate or Melamine Formaldehyde Sulphonate polymer, is a highly effective water-reducing agent and superplastiziser for promoting accelerated hardening and free flowing concrete,cement and plasters. It is suitable for use in tropical and hot climatic conditions.
Use
Sulfonated Melamine Formaldehyde is used as a superplastiziser to produce free flowing concrete in:
– Floor slabs
– Foundations
– Slender components with densely packed reinforcement
– Walls and columns
– Beams and slabs
Sulfonated Melamine Formaldehyde is used as a water-reducer in the manufacture of high early strength concrete for:
– Pre-cast concrete elements
– Bridges and cantilever structures
– Pre-stressed concrete
It is also used for high strength gypsum,gypsum based self-leveling,wall plaster,gypsum based putty powder etc.
Advantage
Sulfonated Melamine Formaldehyde provides the following properties:
As a Superplastiziser
– Substantial improvement in workability without increased water or the risk of segregation.
– Normal set without retardation even when overdosed.
As a Water Reducer
– Up to 20% water reduction.
– 40% increase in 28 day strengths. High strengths after 8 hours.
– Increased frost resistance.
– Increased water tightness.
Test standards
Sulfonated Melamine Formaldehyde complies with ASTM C-494 Type A & F and EN 934-2 :2001
Type:Melamine Formaldehyde Condensate
Form: white powder
Packaging:25kgs/bag
Storage Condition: In a dry area between 5ºC and 35ºC. Protect from direct sunlight
Shelf life 12 months minimum if stored properly in original unopened packaging
Technical Data
Density at 25℃ Approximately 0.65kg/cm3
pH value Approximately 7–8
Chloride content 0.03%-0.04%
Application Details
Dosage
1.0%-1.5% by weight of cement. It is advisable to carry out trial mixes to establish the exact dosage rate required.
Dispensing
Sulfonated Melamine Formaldehyde can be added separately to the fresh mixed concrete or directly to the mixing water prior to its addition to the aggregates.
When added separately to the freshly mixed concrete, further mixing must take place for at least one minute per cubic meter.
Concrete Placing
The standard rules of good concreting practice (production as well as placing) must also be observed when using Sulfonated Melamine Formaldehyde concrete.Fresh concrete must be cured properly.
Curing
Fresh concrete must be cured properly, especially at high temperatures in order to prevent plastic and drying shrinkage.
Compatibility
Sulfonated Melamine Formaldehyde is compatible with sulphate resistant cement. Pre-trials are recommended if combinations with the above products are being made.
Please consult our Technical Services Department.
Cleaning
Clean all equipment and tools with water immediately after use.
Remarks
When accidental overdosing occurs, the set retarding effect increases, however, no excessive amount of additional air will be entrained. During this period the concrete must be kept moist in order to prevent premature drying out.
Safety
Precautions
Accidental splashes to the skin must be washed off with water and soap.
Accidental splashes to the eyes or mucous membrane must be rinsed with clean warm water. Seek medical attention without delay.Skin barrier cream, safety goggles and rubber gloves are recommended.
Melamine Formaldehyde Sulfonate
Sulfonated melamine formaldehyde (SMF) is a polymer used in cements and plaster based formulations to reduce water content, while increasing the fluidity and the workability of the mix. In concretes, addition of SMF in an appropriate mix design results in lower porosity, higher mechanical strength, and an improved resistance to aggressive environments.
Phosphorus-based and Intumescent Flame Retardants
Polymer Green Flame Retardants
Melamine polyphosphate
Melamine derivatives are salts with organic or inorganic acids such as boric acid, cyanuric acid, and phosphoric or polyphosphoric acid.
These derivatives have higher decomposition temperatures (melamine cyanurate (MC), 310 °C; melamine polyphosphate (MPP), 360 °C) in comparison to melamine (250 °C) alone, are less soluble in water, and can add other features to performance such as nondripping (cyanuric acid) or char formation (boric acid, phosphoric acid). Melamine homologs such as melam, melem, and melon have even higher decomposition temperatures with 400 °C and above, but they have found only experimental use so far.
MC is used in the production of halogen-free flame-retarded unfilled and mineral-filled PAs for electrical and electronic applications, in thermoformable polyurethane foams, and in polypropylene intumescent formulations in conjunction with APP. Melamine phosphate and melamine pyrophosphate are mainly used in intumescent coatings and in glass-filled polyolefins and PAs.
Melamine phosphate and melamine pyrophosphate can also be used in paper, textiles, and wood laminates to effect fire-retardant barriers.
Melamine borate is mainly used in intumescent coatings, in various polyolefins, in PVC as an antimony-free synergist and smoke suppressant, and in textile backcoatings.
Like APPs, melamine phosphates are also substances combining the synergistic effect of nitrogen- with phosphorus-containing components in one salt.
Based on increasing thermal stability the melamine phosphates can be ranked as follows: melamine phosphate < melamine pyrophosphate < melamine polyphosphate.
Melamine monophosphate is a salt of melamine and phosphoric acid. Above ∼200 °C melamine phosphate will react with melamine pyrophosphate with release of reaction water, which will result in a heat sink. Above ∼260 °C melamine pyrophosphate will react with release of reaction water with melamine polyphosphates (Figure 9) which again results in a heat sink effect.
Above 350 °C, melamine polyphosphate undergoes endothermic decomposition thus acting as a heat sink and cooling the combustion source.
The released phosphoric acid acts to coat and therefore shield the condensed combustible polymer.
The phosphoric acid along with the polymer also works to form a char around the fuel source (polymer), thus reducing the amount of oxygen present at the combustion source. The melamine released is also a blowing source, which blows up the char, resulting in an intumescent behavior.
Compared to APP, MPP is more thermally stable and less sensitive to hydrolysis, but its FR effect is lower than that of APP, so it could not replace APP in intumescent coatings and polyolefin FRs.
It was originally developed for glass fiber-reinforced (GF) PA 66 and gives a V-0 at 25% dosage, but it fails to improve the flammability characteristics of PA 6 at reasonable levels. Jahromi demonstrated that MPP depolymerizes at above 350 °C, inducing significant cross-linking (as evidenced by increase in viscosity) in PA 66 and leading to a drastic depolymerization of PA 6 (as evidenced by a decrease in viscosity) [29].
MPP is today mostly used in combination with other FRs, such as metal phosphinates (see phosphinate chapter), metal hydroxides, and phosphates.
It is characterized by its good thermal stability and a low impact on the glass-transition temperature (Tg).
As mentioned, under thermal stress, melamine derivatives decompose endothermically (heat sink) and release inert nitrogen gases (e.g. ammonia) that dilute oxygen and the flammable gases in the flame.
Often phosphoric acid is also formed as a decomposition product and promotes the formation of insulating char on the surface of the polymer.