The influence of five low‐molecular weight ethers of different chemical structure on the solution‐precipitation cationic copolymerization of 1,3,5‐trioxane with 1,3‐dioxolane in the presence of BF3 · OBu2 as an initiator has been studied.
The following ethers were considered: di‐n‐butyl ether (Bu2O), dibenzyl ether (Bz2O), tetrahydrofuran (THF), 1,4‐dioxane (DO), and diethylene glycol dimethyl ether (Diglyme).
It has been found, that there are several effects of these ethers on the copolymerization, namely decreasing the copolymerization rate and yield, protecting the copolymer against the destructive influence of copolymerization catalyst, decreasing the unstable fraction content und preventing the agglomeration of precipitated copolymer particles. Similar effects were previously observed for high‐molecular weight polyether, i.e. poly(ethylene oxide). The effectiveness of ethers in respect of retardation effect on the copolymerization is increased in the following sequence:
This sequence is correlated with the nucleophilicity of low‐molecular weight ethers.