Synthesis of a new type poly(oxymethylene) with a terminal unit of long alkyl group using stearyl alcohol as a chain transfer agent

The authors synthesized a new type poly(oxymethylene) with a long alkyl gro up using stearyl alcohol (1-octadecanol) as a chain transfer agent during t he polymerization of trioxane. In the case of solution polymerization of tr ioxane using 1,2-dichloroethane as a solvent and 1,3-dioxolane as a comonom er, it was found by gas-chromatographical method that during the polymeriza tion most stearyl alcohol fed to the polymerization system was consumed, an d by H-1-NMR method octadecyl unit was confirmed in polymer. However, there was some di difference between the consumed stearyl alcohol and octadecyl unit found in polymer. It was observed that the octadecyl unit in polymer w as less than the consumed stearyl alcohol. It was deduced that the low mole cular weight oxymethylene copolymer with relatively higher comonomer incorp oration was soluble to the methanol, which was used as a washing solvent. I n the case of bulk polymerization of trioxane using no solvent, fairly goad agreement was observed between the consumed stearyl alcohol and octadecyl unit found in polymer except in the case of high feed of stearyl alcohol. H -1-NMR analysis of the obtained polymer showed that the proton of some meth ylene of octadecyl group attached to the polymer end shifted to the lower m agnetic field compared to that of the free stearyl alcohol. The oxymethylen e unit connected to the stearyl group was also observed at 4.87 ppm, which proved octadecyl group was surely connected to the poly(oxymethylene) end.