Trioxane, formaldehyde polymer Properties

Trioxane oi alpha-trioxymethylene, (CHi>0)3, the cyclic trimer of formaldehyde, is a stable chemical indiiridual possessing unique, well-defined properties. Because of preparational difficulties, it has in the past been studied by veiy few iQ, estigators. Its obscurity has also been further enhanced by the incoiTect use of the term ririoxymethylene as a designation for linear formaldehyde polymers. 

Starting ingredients may be formaldehyde or the cyclic trimer rrioxane, CH2OCH2OCH2O. Both form polymers of similar properties. Boron trifluoride of other Lewis acids are used to promote polymerization where trioxane is the raw material. 

Acetal homopolymer is a highly crystalline thermoplastic manufactured by polymerization of formaldehyde and capping the two ends of the polymer chain with acetate groups (Table 6.2). It is called polyoxymethylene (POM) and has a backbone consisted of repeating —CH2O—units. Acetal copolymers are produced by copolymerization of trioxane and small amounts of a comonomer. The comonomer randomly distributes carbon—carbon bonds in the polymer chain, which stabilizes the resin against environmental degradation. The low cost of acetals compared to other polymers with similar performance and their mechanical, chemical, and electrical properties, allows them to replace metal and other structural materials in many applications. 

---