IDENTIFICATION

CH₃O - CH₂ - OCH₃ METHYLAL

EINECS n°: CAS n°: UN n°: CTFA Name:

2037142 109 -87-5 1234 methylal

Also called : Dimethoxymethane (I.U.P.A.C.) or Methylene dimethylether.

PHYSICAL PROPERTIES

Methylal is a colourless, highly volatile solvent with a low boiling point, low viscosity and an excellent dissolving power.

Physical properties

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Boiling point (1 atm):	42.3°C (108.14°F)
Molecular weight :	76.1
Density d20/4:	0.860
Viscosity (30°C) :	0.325 cps
Melting point :	-104.8°C (-156.64°F)
Surface tension (20°C) :	21.12 dyn/cm
Evaporation rate (DIN 53170) :	1.36 vs diethyl ether
	0.11 vs butyl acetate
Flash point (open cup) :	-18°C (-0.4°F)
Autoignition temperature :	237°C (458.6°F)
Explosion limits :	1.6 % vol (LEL)
	17.6 % vol (UEL)
Vapour pressure (20°C) :	44.103 Pa
Dielectric constant (20°C) :	2.645
Dipolar moment (20°C) :	0.74 D

Solvent Properties

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Methylal has an exceptional solvent power with medium polarity, conferring it a unique amphiphilic character.

Solubility parameters		in Mpa1/2	in cal1/2 cm-3/2
Hildebrandt (25°C) : Hansen dispersion : polarity : hydrogen bonds :	d dd dp dh	17.5   15.1 1.8 8.6	8.5   7.4 0.9 4.2
Kauri-Butanol index (ASTM D 1133-90, gum 4939) : 164

Miscibility

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Methylal is fully miscible in organic solvents.
Methylal is partially miscible in water (up to 33 %).
In the presence of alcohol or a polar solvent, methylal is fully miscible in water, as is shown in the following ternary diagram :

CHEMICAL PROPERTIES

Methylal belongs to the acetal family.

Stability

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Methylal has an excellent stability.

Hydrolysis :

in the presence of water, it is stable in basic and neutral medium. In acid medium, there is no hydrolysis if pH > 4.5 - 5.

Peroxides :

methylal does not form peroxides and does not need to be stabilized.
It can be regenerated without decomposition, and is suitable for all recycling processes.

Reactivity

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Reactant of chloromethylation, methoxymethylation, transacetalization, methylenation.
Source of formaldehyde and methanol by acid hydrolysis.

APPLICATIONS

Thanks to

• an exceptional solvent power,
  
• its amphiphilic character : methylal is both hydrophilic and lipophilic,
  
• an extremely low viscosity,
  
• a low surface tension,
  
• a particularly high evaporation rate,

methylal finds applications in numerous fields :

• aerosols for cosmetic and technical applications
  methylal is an extraordinary solvent for aerosols and pump sprays thanks to its
  • excellent solvency
  • extremely low viscosity
  • compatibility with propellants, air and CO2 included
  • high evaporation velocity
  It improves the spray quality and the product performances, in solvent or water-based formulae.
  
  
• paints and varnishes
  A high solvency and low viscosity make methylal indispensable for metallic paints or wood varnishes.
  
  
• paint strippers
  The low molecular dimension, the low viscosity and surface tension associated with a high solvent power make methylal an excellent component of environment friendly paint strippers.
  
  
• cleaning and degreasing solvents
  Oleophilic character, solvency, extremely high volatility are helpful properties for cleaning solvent blending.
  
  
• pharmaceuticals
  Besides the galenic applications for which methylal is used as a carrier for active ingredients, methylal is a reagent in pharmaceutical synthesis and is used as a substitute for diethyl ether (no peroxides).
  
  
• synthesis - polymers - resins
  Methylal is a useful reagent for the production of ion exchange resins and crucial as a chain length regulator in the polyacetal resin manufacture.
  
  
• adhesives
  Unique solvent properties associated with quick drying are useful in glue formulations.
  
  
• extraction
  Good penetration capabilities, low toxicity and unique solvency parameters make methylal suitable for many extraction processes, for fragrances or aromas.
  
  
• fuel additive
  Smoke reduction.
  
  
• Insecticides
   
• etc...
  

LAMBIOTTE & Cie propose various methylal grades meeting the standards of the cosmetic, the pharmaceutical synthesis, the coating and the cleaning industry.
LAMBIOTTE & Cie will be pleased to supply further information on the above applications.

SPECIFICATIONS

	Cosmetic grade	Anhydrous grade	Pure grade	Technical grade
Methylal	99.5 % min.	99.9 % min.	99.5 % min.	93 % min.
Methanol	< 1 ppm	< 0.05 %	< 0.05 %	6.5 % max
Formaldehyde	< 1 ppm	< 0.005 %	< 0.0005 %	< 0.02 %
Water	< 0.5 %	< 0.03 %	< 0.5 %	< 0.25 %

VOC

HEALTH AND SAFETY

Toxicity

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Methylal has an extremely low toxicity.

- TLV (MAK) : - Acute toxicity : - Acute inhalation toxicity :   - Subacute inhalation : - Subchronic inhalation : - Eye irritation : - Skin irritation : - Dermal sensitization : - Ames test :

1000 ppm LD50 above 7 g/kg LC50 = 15,000 ppm LD50 = 18,354 ppm NOEL = 4,000 ppm (8 x 6 h) NOEL = 2,000 ppm minor to moderate none to slight not allergenic no mutagenic activity

Complete report available upon request.

Ecotoxicity

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Methylal is a very safe product for the environment :

no effect of methylal observed on bacteria, Daphnids, fish (Brachydanio Rerio)
or green algae.

Methylal is biodegradable (ISO/DIS 8192)

Atmospheric chemistry of methylal

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VOC	The degradation of methylal in the atmosphere happens through its reaction with the hydroxyl radical because methylal does not photolyse. The formation of ozone needs several reactional steps and the velocity of the degradations during the added steps is extremely low. Therefore the contribution of methylal to the formation of tropospheric ozone should be low.
GWP	Methylal has an atmospheric lifetime of 58 hours, which indicates that the global warming potential of methylal is negligible.
ODP	Due to the absence of a halogenated atom, the Ozone Depletion Potential of methylal is zero.

HANDLING -STORAGE - TRANSPORT

Labelling

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Methylal does not require a toxic or harmful label.

Methylal must be labelled as follows :

Danger symbol : F : highly flammable
Risk symbol : R11 : highly flammable
Safety recommendation phrases :	S9 : Keep the container in a well ventilated place. S16 : Keep away from sources of ignition - No smoking S33 : Keep precautionary measures against static discharges.

Storage

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Methylal is stable under recommended storage conditions.

Recommended blanketing : air or dry nitrogen
Recommended temperature : maximum 37.8°C (100°F)
Recommended pressure : atmospheric
Bulk quantities : in the open, in detached carbon steel tanks
Small quantities : in a cool, dry, well ventilated area, protected from the sun

Transport

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ADR Class 3, II
I.D. n° : 33
UN n° : 1234
IMO : Class 3
EMS n° : 3-06
MFAG n° : 330

Properties are typical of average lots. Lambiotte makes no representation that the material in any shipment will conform to the values given. Specifications are available on request.