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What is Paraformaldehyade and its uses

Paraformaldehyde is the smallest polyoxymethylene, the polymerization product of formaldehyde with a typical degree of polymerization of 8–100 units. Paraformaldehyde commonly has a slight odor of formaldehyde due to decomposition. Paraformaldehyde is a poly-acetal.Paraformaldehyde forms slowly in aqueous formaldehyde solutions as a white precipitate, especially if stored in the cold. Formalin actually contains very little monomeric formaldehyde,most of it forms short chains of polyformaldehyde. A small amount of methanol is often added as a stabilizer to limit the extent of polymerization.if we talk about reaction Paraformaldehyde can be depolymerized to formaldehyde gas by dry heating and to formaldehyde solution by water in the presence of a base, an acid or heat.The resulting formaldehyde gas from dry heating paraformaldehyde is flammable.


PARAFORMALDEHYADE STRUCTURE

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INDUSTRAIL USES


Paraformaldehyde is a white crystalline solid that is used in a variety of industrial applications

  • Disinfection
  • Adhesives
  • Fumigation
  • Manufacturing phenolic urea and melamine resins
  • Production of ion exchange resins
  • Hardening of glues
  • Manufacture of fluorescent pigments 


Paraformaldehyde is used as a disinfectant, hardening agent and waterproofing agent. It is also used to prepare adhesives, resins and in dentistry as an antiseptic. It is also employed as a thermoplastic.

Once paraformaldehyde is depolymerized, the resulting formaldehyde may be used as a fumigantdisinfectantfungicide, and fixative. Longer chain-length (high molecular weight) polyoxymethylenes are used as a thermoplastic and are known as polyoxymethylene plastic (POM, Delrin). It was used in the past in the discredited Sargenti method of root canal treatment.Paraformaldehyde is not a fixative; it must be depolymerized to formaldehyde in solution. In cell culture, a typical formaldehyde fixing procedure would involve using a 4% formaldehyde solution in phosphate buffered saline (PBS) on ice for 10 minutes. In pathology specimens preparation, usually, the fixation step is performed using 10% Neutral Buffered Formalin (4% formaldehyde) for, at least, 24 hours.

Paraformaldehyde can be used as a substitute of aqueous formaldehyde to produce the resinous binding material, which is commonly used together with melaminephenol or other reactive agents in the manufacturing of particle board, medium density fiberboard and plywood.paraformaldehyde is a potential carcinogen.Its acute oral median lethal dose in rats is 592 mg

Paraformaldehyde is flammable and has a flash point of 158 °F. It is also a hazard to the environment. 


PACKAGING


Paraformaldehyde is often packed in HDPE bags or polypropylene woven bags for industrial use: 


  • HDPE bags: Paraformaldehyde powder is often packed in 25 or 50 kg HDPE bags. 

  • Polypropylene woven bags: Paraformaldehyde is sometimes packed in 25 or 50 kg polypropylene woven bags with a loose inner polyethylene liner. 

  • Anti-static LDPE bags: Paraformaldehyde prills are sometimes packed in premium anti-static LDPE bags.