The difference between trimerformaldehyde, paraformaldehyde and polyformaldehyde
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What is the difference between triformaldehyde, paraformaldehyde and polyformaldehyde? Explain from their uses, physical properties, chemical properties, etc. This post was last edited by Canghai Yisha on 2008-9-23 10:46 ]
The most important thing is that the uses are different! ! !
common ground: General formula (CH2O)n Differences: Triformaldehyde n=3; Paraformaldehyde n=6--100; Polyformaldehyde n﹥100. Usage: slightly
Triformaldehyde and paraformaldehyde are actually oligomers of formaldehyde, which can also be called solid formaldehyde. Because they are superior to liquid formaldehyde in terms of transportation, storage, and use, they are often used as raw materials for the production of high-end chemical products, pesticides, etc. that require formaldehyde. Polyformaldehyde is an engineering plastic, also known as "super steel", and is divided into two types: homopolyformaldehyde and copolymerformaldehyde. Homopolyformaldehyde is a polymer of formaldehyde or trimerformaldehyde, and copolymerformaldehyde is a copolymer of trimerformaldehyde and dioxane or ethylene oxide. It can often be used to replace metals such as copper and aluminum. It is widely used in automobiles, electronics and other industries. It can also be used to make gears, zippers, valves and other products.
The difference between low molecular weight, medium molecular weight and high molecular weight.
Paraformaldehyde, also known as solid formaldehyde, is a low molecular weight mixture of formaldehyde with a formaldehyde content of 85-97%. The general formula is HO(CH2)nH, n=8-100, and the melting point range is 120-170°C. Because paraformaldehyde is solid, the content of the active ingredient formaldehyde is higher than industrial formaldehyde, making it easier to store and transport. Mainly used in chemical, pesticide, resin, papermaking, foundry, breeding and other industries, especially in synthetic products that require the use of anhydrous or low-moisture formaldehyde as raw materials. The international trend is: Applications that originally used industrial formaldehyde as raw materials are now using high-concentration formaldehyde as raw materials during technological upgrading. Paraformaldehyde is usually produced from industrial formaldehyde through vacuum concentration, polymerization, dehydration, drying and other processes. The selection of the manufacturing process and the control of operating conditions affect the molecular weight of paraformaldehyde and various indicator properties, especially water solubility. The dissolution process of paraformaldehyde in water is accompanied by depolymerization, depolymerizing into formaldehyde hydrates with lower molecular weights. Good water solubility means It means good dissociation and good water solubility. Paraformaldehyde easily releases formaldehyde when it is thermally decomposed. Since reactions using paraformaldehyde as raw materials usually involve formaldehyde directly participating in the reaction, good water solubility and dissociation means high reactivity. Therefore, many manufacturing industries that use paraformaldehyde hope to obtain paraformaldehyde products with good water solubility.
Polyacetal (English: polyformaldehyde) thermoplastic crystalline polymer. Known as "super steel", it is also called polyoxymethylene. The structure is, the English abbreviation is POM. Usually, the polymer obtained by formaldehyde polymerization has a low degree of polymerization and is susceptible to thermal depolymerization. Around 1955, DuPont polymerized formaldehyde to obtain formaldehyde homopolymer. Polyformaldehyde is easy to crystallize, with a crystallinity of more than 70%. The melting temperature of homopolymer is about 180°C. The scientific name of polyoxymethylene is polyoxymethylene (POM). Polyoxymethylene is a linear polymer with no side chains, high density, and high crystallinity, with excellent comprehensive properties. Polyformaldehyde is a hard and dense material with a smooth and shiny surface, light yellow or white, and can be used for a long time in the temperature range of -40-100°C. Its wear resistance and self-lubricating properties are also superior to those of most engineering plastics, and it also has good oil resistance and peroxide resistance. It is very intolerant to acid, alkali and moonlight ultraviolet radiation. Polyformaldehyde has a tensile strength of 70MPa, low water absorption, dimensional stability, and gloss. These properties are better than nylon. Polyformaldehyde is a highly crystalline resin and is the toughest among thermoplastic resins. It has high heat resistance, bending strength, fatigue resistance, excellent wear resistance and electrical properties.
Triformaldehyde; 1,3,5-trioxane; trioxane; trioxane; 1,3,5-trioxane; 1,3,5-trioxane; 1,3,5-trioxane; trimerformaldehyde; symmetric trioxane; 1,3,5-Trioxane; Metaformaldeh yde;Trioxane;Trioxymethylene;s-trioxane;1,3,5-trooxacyclohexane;1,3,5-trioxan;aldeform;formaldehyde, trimer;marvosan;s-trixane 10-88-3 Molecular formula: C3H6O3 Molecular mass: 90.08 Boiling point: 114-116℃ Melting point: 61-62℃ Chinese name: trimerformaldehyde； 1,3,5-trioxane ； trioxane ； trioxane ； 1,3,5-trioxane ； 1,3,5-trioxane ； 1,3,5-trioxane ； Triformaldehyde ； Symmetrical trioxane English name: 1,3,5-Trioxane ； Metaformaldehyde ； Trioxane ； Trioxymethylene ； s-trioxane ； 1,3,5-trioxacyclohexane ； 1,3,5-trioxan ； aldeform ； formaldehyde, trimer ； marvosan ； s-trixane Property Description: White crystal. The melting point is 64°C and the boiling point is 114.5°C. Sublimates at 46°C. Easily soluble in water (17.2g/100ml at 18℃, 21.1g/100ml at 25℃) ； alcohol ； ether ； Bingtong ； Chloroform ； carbon disulfide ； Aromatic hydrocarbons and other organic solvents, slightly soluble in petroleum ether and pentane. It can form an azeotrope with water, with a boiling point of 91.4°C and containing 70% (weight) trioxane. The aqueous solution can be gradually depolymerized by strong acid, but does not react with alkali. In non-aqueous systems, it can be converted into monomers by a small amount of strong acid. Has a chloroform-like odor. Production method: It is produced by continuous distillation of a 60% formaldehyde aqueous solution containing 2%-5% sulfuric acid, and the residual liquid is extracted with benzene and then distilled. Metaformaldehyde can also be generated under certain conditions. The melting point of formaldehyde is 112°C and the boiling point is 175°C. Both parformaldehyde and metaldehyde can be re-decomposed into formaldehyde under the action of acid, and both are special commercial forms of formaldehyde. Usage: Intermediate for engineering plastics, polyformaldehyde and other chemicals
common ground: They are all solid formaldehyde condensates. Differences: Triformaldehyde and paraformaldehyde depolymerize relatively easily ； Polyoxymethylene is more difficult.
When using paraformaldehyde to replace industrial formaldehyde solution, will paraformaldehyde depolymerize at 150 degrees?