transition temperature of the purified polymer was 130−134 °C. NMR measurements indicate that the purified polymers have mostly vinyl addition polymer structure. Nevertheless, we suppose that the pristine polymers contain structural units formed by ring-opening polymerization. The molecular weight of poly(PFMMD) samples can be regulated using carbontetrachloride, carbon tetrabromide, and sulfuryl chloride
METHOD OF PRODUCING PERFLUORO(2-METHYLENE-4-METHYL-1,3-DIOXOLANE)
申请人:TOSOH CORPORATION
公开号:US20220002262A1
公开(公告)日:2022-01-06
Provided is a method of producing perfluoro(2-methylene-4-methyl-1,3-dioxolane), the method including at least following processes (1) to (3):
(1) reacting at least one of perfluoro(2,4-dimethyl-2-fluoroformyl-1,3-dioxolane) and a hydrolysis product thereof with a basic aqueous solution containing one or more cations selected from the group consisting of alkali metal ions and alkaline earth metal ions and then separating a liquid containing produced perfluoro(2,4-dimethyl-1,3-dioxolane-2-yl)carboxylic acid alkali metal salts or perfluoro(2,4-dimethyl-1,3-dioxolane-2-yl)carboxylic acid alkaline earth metal salts by a liquid separation operation;
(2) performing one or more water content reduction treatments selected from the group consisting of water evaporation and water adsorption on the liquid containing the obtained perfluoro(2,4-dimethyl-1,3-dioxolane-2-yl)carboxylic acid alkali metal salts or perfluoro(2,4-dimethyl-1,3-dioxolane-2-yl)carboxylic acid alkaline earth metal salts to obtain perfluoro(2,4-dimethyl-1,3-dioxolane-2-yl)carboxylic acid alkali metal salts or perfluoro(2,4-dimethyl-1,3-dioxolane-2-yl)carboxylic acid alkaline earth metal salts in a solution state or a solid state; and
(3) causing a decarboxylation reaction in a liquid phase system with the obtained perfluoro(2,4-dimethyl-1,3-dioxolane-2-yl)carboxylic acid alkali metal salts or perfluoro(2,4-dimethyl-1,3-dioxolane-2-yl)carboxylic acid alkaline earth metal salts in a solution state or a solid state to produce perfluoro(2-methylene-4-methyl-1,3-dioxolane).