摘要:
Purification process of amorphous polymers comprising the following steps:
a) the amorphous polymer is dissolved in a fluorinated solvent; b) the solution containing the polymer is microfiltered by semipermeable membranes having a porosity in the range 0.05 - 0.5 µm, and the permeate forms the polymeric solution purified by contaminants in suspension; c) the permeate coming from b) is ultrafiltered/nanofiltered by membranes with porosity in the range 10-500 kDa, and the retentate is formed by the polymeric solution purified from the contaminants in solution.
摘要:
Semipermeable porous membranes having an average pore diameter in the range 0.01-3 µm, and porosity in the range 30%-90%, based on semi-crystalline fluoropolymers and the respective preparation process, wherein the semi-crystalline fluoropolymers comprise:
(a) from 10 to 70% by moles of ethylene, (b) from 30 to 90% by moles of a fluorinated monomer selected from tetrafluoroethylene, chlorotrifluoroethylene, or mixtures thereof, (c) from 0.1 to 30% by moles, with respect to the total amount of monomers (a) and (b), of a hydrogenated monomer of formula:
CH 2 =CH-(CH 2 ) n -R 1 (I)
wherein R 1 = -OR 2 , or -(O) t CO(O) p R 2 wherein t and p are integers equal to 0.1 and R 2 is a linear or branched C 1 -C 20 alkyl, or a cycloalkyl, optionally containing heteroatoms and/or chlorine atoms, preferably heteroatoms are O or N; R 2 can optionally contain one or more functional groups, preferably selected from OH, COOH, epoxy, ester and ether group; R 2 can optionally contain double bonds, or it can be H; n is an integer in the range 0-10.
摘要:
Ternary mixtures, particularly suitable for removing oily substances having both an hyrogenated and fluorinated or mixed basis, essentially consisting of: (a) water; (b) terbutanol; (c) a fluoropolyoxyalkylene having hydrogenated end groups and/or hydrogenated repetitive units. Such mixtures have high flash point, are non toxic and with null depleting potential of the ozone and show a ternary diagram characterized by a wide monophasic zone, wherein the three components form limpid and stable solutions.
摘要:
Object of the present invention is a process for preparing vinylidenefluoride (VDF) polymers which comprises polymerizing VDF, optionally in association with other fluorinated olefins, in an aqueous medium in the presence of a radical initiator and of 1,1,1-trifluoro-2,2-dichloroethane (HCFC-123) as chain transfer agent. A final product with very good colour characteristics (appearance), substantially devoid of discoloration effects at high temperatures, is so obtained.
摘要:
In a process of (co)polymerization in aqueous emulsion of fluorinated olefinic monomers it is added to the reaction medium a microemulsion of fluoropolyoxyalkylenes having hydrogenated end groups and/or hydrogenated repetitive units. A remarkable reduction in the reaction induction period is so obtained, with formation of a product with improved mechanical properties and higher thermal and chemical resistance.
摘要:
A process for preparing a solution and/or dispersion containing sulphonic (per)fluorinated ionomers having -SO 3 M functional groups, wherein M is selected from H, Li, Na, K, NR 4 (R equal to or different from each other are selected from H, CH 3 ,C 2 H 5 ), characterized in that it dissolves the above defined ionomers at a temperature comprised between the room temperature and about 150°C, in a monophasic ternary mixture essentially constituted by water, by a C 1 -C 4 alcohol and by a fluoro(poly)oxyalkylene having one hydrogen atom in at least a fluorinated end group; the dispersed polymer particle sizes are in the range 30-100 nm.
摘要:
Amorphous fluoropolymer selfsupported manufactured articles obtained by casting from solution in a single step, characterized in that they are obtained by the polymerization of a structure (I), optionally and preferably with a monomer having a structure (II): wherein: R f is a C 1 -C 5 perfluoroalkyl radical; X 1 and X 2 are selected from F and CF 3 ; Y 1 and Y 2 are selected from F, Cl, H, CF 3 , OR f ; having refractive index lower than 1.35, trasmittance higher than 90% in the radiation field 300-2,000 nm wave length, and thickness higher than 20-25 µm.