Paraformaldehyde
Paraformaldehyde
Paraformaldehyde is a white solid-low molecular weight polymer of formaldehyde
Depending on the sizes of its flakes/granules, it contains over 90-%w of formaldehyde (the rest is water).
Like formaldehyde in aqueous solution, it is very reactive and depolymerizes readily under conventional processing conditions. It is easy to obtain a formaldehyde solution by simply dissolving paraformaldehyde in hot water. When consistent with the subsequent use of the solution, a pH adjustment may be made to speed up the process since, at high values of pH, the dissolving rate increases.
The typical pH value of a 37%w solution obtained from paraformaldehyde without any addition is 3,5. When using dilution water at 55°C and adjusting the pH to 8,0, such solution is ready in 20 minutes only.
However, paraformaldehyde needs not to be previously dissolved in water in order to take part in a chemical reaction.
Easy to store and use, it can replace the formaldehyde solution in most reactions, offering outstanding advantages.
ALDER produces and sells paraformaldehyde in two different forms: free-flowing flakes or powder.
Paraformaldehyde has the following main technical properties:
|
Property
|
Value
|
|---|---|
| Appearance |
White solid, with pungent typical formaldehyde smell
|
| Flammability |
Combustible, with flash point (tag open cup) of about 95°C
|
| Vapour pressure |
1 – 3 mmHg at 30°C, varying with the air humidity
|
| Melting point |
About 150°C in sealed tube; sublimes rapidly at 130°C to 140°C
|
| Bulk density |
About 0,70 – 0,75 kg/ dm3
|
|
Guaranteed
|
Flakes form
|
Powder form
|
|---|---|---|
| Assay, as formaldehyde | 91±1 wt% | 91,0±1,5%w |
| Water content | 9.00±1 wt% | 9,0±1,5%w |
| Acidity, as formic acid | max 0.07 wt% | max 0,07%w |
| Ash content | max 0.04 wt%. | max 0,04%wt |
| Iron content | max 0.0003 wt% | max 0,0003%w |
| Particle size |
Most of the flakes with dimensions
of about 5×10 mm, thickness about 2 mm
|
0,2 – 2,0 mm
|
Packaging
Paraformaldehyde is normally supplied in 25 kg polyethylene bags on 1.000 kg polyethylene film shrink-wrapped pallets or in 500 or 1.000 kg big bags on pallet. Other types of containers may also be used; shipment in bulk may be evaluated too.
Applications
The most important use of paraformaldehyde is as a source of formaldehyde groups in the production of many thermosetting resins, together with phenol, urea, melamine, resorcinol and other similar reagents.
These resins are used:
• As molding powders;
• In the wood industry as glues for chipboard, plywood and furniture;
• As bonding resins for brakes, abrasives and foundry dyes;
• As finishing resins for paper and textiles;
• As driers and glossing agents for paints;
• As insulating varnishes for electrical parts.
Some typical formulations to produce such resins starting from paraformaldehyde include dichloroethyl formal, methyl phenol, disinfectants, insecticides, pharmaceuticals such as vitamin A, embalming preparations, dyestuff and special plasticizers.
In addition, paraformaldehyde is used as a fungicide and bactericide in industries as varied as crude oil production, beet sugar refining and warehousing.
Paraformaldehyde has widespread acceptance as an additive to stop fermentation of the starch on oil-well-drilling muds.
The sugar beet industry used it to minimize the growth of algae in its continuous diffusers.
Hotels and motels often use it, with or without added mothproofing agents, in humid areas in small bags hung in closets to prevent the formation of mildew.
MSDS
CAS number: 30525-89-4
EC number: 608-494-5
Paraformaldehyde MSDS is available at request to Alder website contacts.
Labelling of the product according to CLP is as it follows:
Please check additional information available at: https://echa.europa.eu/