Copolymerization of 1,3,5-trioxane

Thermally stable polyacetals are prepared by cationic TXN copolymerization with a small amount of comonomer (DXL, EO). Thus, the mechanism of TXN copolymerization was more frequently studied than its homopolymerization. 

In regard to the copolymerization process, we have to describe the rates of incorporation of comonomers and distribution of different units in the resulting copolymer (microstructure). In this section we briefly discuss characteristic features of copolymerization of TXN with cyclic formals and then with other oxacyclic and some vinyl monomers. 

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Copolymer. Acetal copolymers are prepared by copolymerization of 1,3,5-trioxane with small amounts of a comonomer. Carbon-carbon bonds are distributed randomly in the polymer chain. These carbon-carbon bonds help to stabilize the polymer against thermal, oxidative, and acidic attack. 

Cationic Copolymerization of 1,3>5-Trioxane with 1,3-Dioxolane (Ring-Opening Copolymerization)... 

It has to be remembered, however, that this process may be complemented by the reversibility of the propagation step. In the copolymerization of 1,3,5-trioxane with 1,3-dioxolane (or ethylene oxide), the complex set of equilibria is established, involving comonomers but also formalde-... 

Table 7.6 Copolymerization of 1,3,5-trioxane (7mol-l ) with 1,3-dioxolane (0.35 mol-1 ) m cyclohexane at 60 °C 501...

Table 7.20. Copolymerization of 1,3,5-Trioxane with epoxides, bulk polymerization, 70 °C 106)...

General Features of Heterogeneous Polymerization of 1,3,5-Trioxane The Induction Period in the Homo- and Copolymerization of 1,3,5-Trioxane... 

Table 6 Copolymerization of 1,3,5-trioxane with 1,3-dioxepane at 80 °C in bulk. DXP concentration at the end of the induction period depending on the initial TOX/DXP ratio. ...

Figure 2 Copolymers obtained in copolymerization of 1,3,5-trioxane and 1,3-dioxolane carried out in the presence of poly(ethylene oxide) (Mn = 15 000). Initial concentrations of 1,3,5-trioxane and 1,3-dioxolane were equal to 7.0 and 0.35 molkg" respectively.

Figure 4 Schematic illustration of the cationic dispersion copolymerization of 1,3,5-trioxane and 1,3-dioxolane. (a) - solution before beginning of the polymerization, (b) - polymerization in solution, length of polymer chains is shorter than the critical one, (c) - chain-to-globule transition and formation of the primary particles, (d) - formation of aggregates of the primary particles, polymerization in aggregates, (e) - escape of growing species from particle aggregates to solution and formation of new primary particles, (f) - formation of new aggregates.

Nagahara H, Kagawa K, Iwaisako T, Masamoto J (1995) Initiation mechanism of the copolymerization of 1,3,5-trioxane and ethylene oxide. Ind Eng Chem Res 34 2515-2519... 

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