1.3.5- Trioxane 1,3,5-trioxacyclohexane

A great majority of polymerizations are simultaneously affected by many physical and chemical factors, and their course is the result of a superposition of these effects. Only in rare cases does one of these factors dominate and the polymerization is formally simplified. In topochemical polymerizations, the growth of macromolecules is governed by forces in the crystal lattice of the monomer. Solid-state polymerization of trioxane (trioxacyclohexane) is a typical example of topochemical polymerization. 

The term "acetal resins" commonly denotes the family of homopolymers and copolymers whose main chains are completely or essentially composed of repeating oxymethylene units (—CH2—O—). The polymers are derived chiefly from formaldehyde or methanal [50-00-00] either directly or through its cychc trimer, trioxane or 1,3,5-trioxacyclohexane [110-88-3]. 

Formaldehyde, in aqueous acidic solution, undergoes cyclotrimerization to trioxane (1,3,5-trioxacyclohexane), and also disproportionation to methanol and formic acid, with some resultant formation of methyl formate. The kinetic behaviour observed suggests a significant autocatalysis by formic acid. 

Synonyms Acetaldehyde, trimer Elaldehyde Paraacetaldehyde Paracetaldehyde Paral PCHO 2,4,6-Trimethyl-1,3,5-trioxacyclohexane 2,4,6-Trimethyl-1,3,5-trioxane 2,4,6-Trimethyl-s-trioxane s-Trimethyltrioxymethylene Empirical C6H12O3... 

Synonyms Metaformaldehyde Polyoxymethylene Triformol 1,3,5-Trioxacyclohexane Trioxan... 

Poly(oxymethylene), with the monomeric unit -(rCUiO, can be produced from formaldehyde, HCHO, or its cyclic trimer, trioxane (1,3,5-trioxacyclohexane). The commerical polymer obtained from formaldehyde is also known as polyacetal homopolymer, and that from trioxane is known as polyacetal copolymer. 

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