MXPA98007884A - Process for the manufacture of a polymer porosomediante the use of a porog - Google Patents

Abstract

The invention relates to a process for producing a porous polymer, which comprises the steps of: 1) dispersing a porogen in a continuous phase of monomer component, wherein the continuous phase of monomer component comprises at least one monomer having at least one a unit of perfluoropolyether, and wherein the porogen is an optionally substituted poly (alkylene) glycol, 2) then, polymerizing the continuous monomer phase, and 3) removing the pore from the pore polymer.

Description

PROCESS FOR THE MANUFACTURE OF A POROUS POLYMER THROUGH THE USE OF A POROGEN The present invention relates to a process for producing porous polymers, in particular to a process for polymerizing or copolymerizing monomers incorporating perfluoropolyethers to form porous polymers, and to porous polymers comprising perfluoropolyethers obtained in accordance with this process. In many applications, it has been found convenient for the polymers to be porous. The degree of porosity required depends on the application. For example, membrane filtration depends on the use of microporous polymers to make separations of different materials. Also, the macroporous sheets of chemically resistant polymers find extensive use as cell dividers in the cells for electrolysis or electricity storage. The pores can be formed in the polymer during the manufacturing process of an article of the desired shape, or they can be formed in the article after manufacture. There are a variety of methods known in the art for the introduction of porosity in synthetic polymers, such as those described in Patent Numbers WO 90/07575, WO 91/07687, US-A-5,244,799, US-A-5, 238, 613, or US-A-4, 799, 931. Some rely on a drilling or taping process after the polymer has been formed. Accordingly, high energy particles or electromagnetic radiation, such as that emitted from laser devices, have been used as described in International Publication Number WO 91/07687. These processes are generally intense in labor and delayed. Less commonly, porosity can be an inherent property of the polymer, and porosity is maintained when the polymer is formed in the desired configuration for a particular application. It is particularly convenient that the porosity is introduced during the steps of polymer formation. This is generally economical, and in appropriate cases, good control over porosity and pore size can be achieved. Polymers based on perfluoropolyethers, in general, have many unique and desirable properties. These include resistance to contamination by proteinaceous materials and other materials, excellent flexibility, transparency, high resistance to extreme temperatures, and exceptional resistance to chemicals and oxidation. These properties would make perfluoropolyether-based polymers particularly suitable for a variety of applications, and would be particularly suitable for use as membranes if methods were available for the economical introduction of porosity. Actually, there has been a felt need for a long time, of membrane materials with the above attributes. The membrane materials based on polytetrafluoroethylene (PTFE) provide a partial solution to this need. However, unlike perfluoropolyether-based polymers, which can be readily cured and formed into articles by their on-site polymerization, polytetrafluoroethylene-based materials suffer from the drawback of being difficult to manufacture to obtain articles. In addition, stretching processes, such as those described in U.S. Patent No. US-A-3, 953, 566 (Gore) give a somewhat limited range of size and shape of the porosities, and are difficult to control. Due to the properties mentioned above, perfluoropolyether-based polymers are highly desirable materials for contact lenses and other ophthalmic devices (U.S. Patent Nos. US-A-4,440,918, US-A-4,818, 801); if these porous materials could be made to allow the transfer of the lacrimal fluids or nutrients, their usefulness would be considerably improved.

Despite the obvious potential advantages of these materials, porous perfluoropolyether polymers have not previously been available. In certain polymers, the porosity can be an intrapenetrating network of holes, closed cells, or a combination thereof. This can be achieved by polymerization in the presence of an insoluble material often referred to as a porogen. Subsequent leaching of the porogen gives rise to interstices throughout the polymeric base material. Sodium chloride is one of these materials that have been used. A drawback of this process is the difficulty in stabilizing the suspension of the porogen in the polymerization mixture. Unstable suspensions can lead to an inhomogeneous and unacceptable product. In many cases, an extensive optimization of the viscosity of the system and the type of porogen is needed to obtain a satisfactory result. In addition, the process is limited in terms of the availability of suitable porogenps to enter the desired ranges of pore sizes. A convenient and versatile method for obtaining porous materials is the polymerization of co-continuous microemulsions. The microemulsion polymerization involves the polymerization of a stable isotropic mixture of an oil phase and a water phase stabilized by surfactants. The oil phase generally contains the polymerizable monomer, which is polymerized around the adjoining droplets of the water phase stabilized by the surfactants, or around a co-continuous water phase. Normally no organic solvents are used in the water phase. It will be appreciated that fluorochemicals such as perfluoropolyethers possess unusual characteristics in their interaction with other substances. One of these characteristics is an unusually low surface energy. Another characteristic is its low solubility in many solvents, especially in water. The low surface energy and the low propensity to adsorb many common materials is partly responsible for their outstanding resistance to contamination and degradation, and the usefulness of fluoropolymers in non-adhesive and dirt-resistant applications. Another consequence of the low surface energy and the solubility of fluorochemical products is that it is very difficult to achieve stable emulsions and microemulsions in aqueous media and in other common media. For example, conventional surfactants well known in the art are not effective in stabilizing aqueous microemulsions containing perfluoropolyethers. According to the above, conventional methods for making microemulsions are not effective for monomers based on perfluoropolyether. Now we have found a reproducible and stable process for the production of porous polymers based on perfluoropolyethers. This makes it possible for these highly stable and resistant materials to be used in a porous form.

In accordance with the above, a process for the production of a porous polymer is provided, which comprises the steps of: 1) dispersing a porogen in a continuous phase of monomeric component, wherein the continuous phase of monomeric component comprises at least one monomer having at least one perfluoropolyether unit, and wherein the porogen is an optionally substituted poly (alkylene glycol); 2) then polymerize the continuous monomeric phase, - and 3) remove the porogen from the porous polymer.

The polymerizable component includes at least one macromonomer having at least one perfluoropolyether unit. It will be understood by those skilled in the art that the terms "perfluoropolyether unit" and "PFPE unit" preferably mean the fraction of the PFPE formula: -OCH2CF20 (CF2CF20) x (CF20) yCF2CH20- (PFPE) where the units CF2CF20 and £ FO can be randomly distributed or can be distributed as blocks throughout the chain, and where x and y can be the same or different, such that the molecular weight of the perfluorinated polyether is on the scale of 242 to 4,000. Preferably, x in the formula (PFPE) is on the scale of 0 to 20, more preferably on the scale of 8 to 12, and is on the scale of 0 to 25, more preferably on the scale of 10 to 14. Yet it is more preferred that x and y in the formula (PFPE) are both different from zero, such that x is on the scale of 1 to 20, more preferably on the scale of 8 to 12, and is on the scale of 1 to 25 , more preferably in the range of 10 to 14. Preferred macromonomers having at least one perfluoropolyether unit include, but are not limited to, those of formulas I, II, and III, as specified below: Macromonomers of the Formula (I): Q- (PFPE-Dn.-L-PFPE-Q (I) macromonomers of the formula (II): Q-B- (L-B) n-T (II) and macromonomers of the formula (III) Q-PFPE-L-M-L-PFPE-Q (III) wherein, in these formulas: Q may be the same or different, and is a polymerizable group, PFPE is a divalent residue of the formula (PFPE) as defined hereinabove, L is a difunctional linking group; n is at least 1; in the macromonomers of the formula (II), each B may be the same or different, and is a difunctional block of a molecular weight on the scale of 100 to 4000, and wherein at least one B is a perfluorinated polyether of the formula ( PFPE), - in the macromonomers of the formula (II), T is a univalent terminal group which is not polymerizable by free radicals, but which may contain other functionality; and in the macromonomers of the formula (III), a residue of a difunctional polymer or copolymer comprising silicone repeat units of the formula IV having a molecular weight preferably in the range of 180 to 6000, and a final functionality as described later: wherein R1 and R2 may be the same or different, and are selected from the group consisting of hydrogen, alkyl, aryl, alkyl substituted by halogen, and the like. R1 and R2 are preferably methyl. In the formulas (I), (II), and (III), it is preferred that n is on the scale of 1 to 5, more preferably n is on the scale of 1 to 3. The macromonomers in a particular manner are particularly preferred. where n is 1.

Q is a polymerizable group that preferably comprises an ethylenically unsaturated moiety that can enter a free radical polymerization reaction. Preferably, Q is a group of formula A: P1- (Y) m- (R'-X1) p- (A) wherein P1 is a free radical polymerizable group; Y is -CONHCOO-, -CONHCONH-, -OCONHCO-, -NHCONHCO-, -NHCO-, -CONH-, -NHCONH-, -COO-, -OCO-, -NHCOO-, or -OCONH-; and p, independently of one another, are 0 or 1; R 'is a divalent radical of an organic compound having up to 20 carbon atoms; X? is -NHCO-, -CONH-, -NHCONH-, -COO-, -OCO-, -NHCOO-, u-OCONH-.

A free radical polymerizable group P - [_ is, for example, alkenyl, alkenylaryl, or alkenylarylenealkyl having up to 20 carbon atoms. Examples of alkenyl are vinyl, allyl, l-propen-2-yl, l-buten-2-, -3-, and -4-yl, 2-buten-3-yl, and the isomers of pentenyl, hexenyl, octenyl, decenyl, and undecenyl. Examples of alkenylaryl are vinylphenyl, vinylnaphthyl, or allylphenyl. An example of alkenylarylenealkyl is o-, m-, or p-vinylbenzyl.

P1 is preferably alkenyl or alkenylaryl having up to 12 carbon atoms, particularly preferably alkenyl having up to 8 carbon atoms, in particular alkenyl having up to 4 carbon atoms. And it is preferably -COO-, -OCO-, -NHCONH-, -NHCOO-, -OCONH-, -NHCO-, or -CONH-, in a particularly preferable manner -COO-, -OCO-, NHCO-, or -CONH-, and in particular, -COO-, or -OCO-. X-L is preferably -NHCONH-, -NHCOO-, or -OCONH-, in a particularly preferable way -NHCOO-, or -OCONH-. In a preferred embodiment, the indices m and p are not simultaneously zero, if p is zero, m is preferably 1. R 'is preferably alkylene, arylene, a saturated divalent cycloaliphatic group having from 6 to 20 carbon atoms, 1 to 1 qui 1 ene, to 1 qu i 1 enari 1 ene, alkylenealkylenealkylene, or arylenenalkylenearylene. Preferably, R 'is a divalent radical having up to 12 carbon atoms, particularly preferably a divalent radical having up to 8 carbon atoms. In a preferred embodiment, R 'is further alkylene or arylene having up to 12 carbon atoms. A particularly preferred embodiment of R 'is lower alkylene, in particular lower alkylene having up to 4 carbon atoms. It is particularly preferred that Q be selected from the group consisting of acryloyl, methacryloyl, styryl, acrylamido, acrylamidoalkyl, urethane methacrylate, or any substituted derivatives thereof. More preferably, Q is a compound of formula A wherein PL is alkenyl of up to 4 carbon atoms, Y is -COO-, R 'is alkylene of up to 4 carbon atoms, X-_ is -NHCOO- , and each of myp is 1. The linking group L can be the divalent residue of any difunctional fraction capable of reacting with hydroxyl. Suitable precursors for L are α, α-diepoxides, α, β-di-isocyanates, α, α-isothiocyanates, α-, β-diacyl halides, α-, β-dithioacyl halides, Q 1 acids, α- dicarboxylics, acids,? -dithiocarboxylic acids, a.,? - dianhydrides, or;,? - dithioisocyanates,,? -dilactones, x,? - dyalkyls, a.,? - dihalides, ethers, dyalkyl esters, amides a ,? -dihydroxymethyl. It is preferred that the linking group be a divalent residue (-C (O) -NH-R-NH-C (O) -) of a di-isocyanate, or the corresponding residue of a dithioisocyanate, wherein R is a radical divalent organic that has up to 20 carbon atoms. The divalent radical R is, for example, alkylene, arylene, at 1 qui 1 enar i 1 ene, ar i 1 enachi 1 ene, or arylenenalkylene arylene having up to 20 carbon atoms, a saturated divalent cycloaliphatic group having from 6 to 20 carbon atoms, or cycloalkylenealkylenecycloalkylene having from 7 to 20 carbon atoms. In a preferred embodiment, R is alkylene, arylene, alkylenearylene, arylenealkylene, or arylenenalkylenearylene having up to 14 carbon atoms, or a saturated divalent cycloaliphatic group having from 6 to 14 carbon atoms. In a particularly preferred embodiment, R is alkylene or arylene having up to 12 carbon atoms, or a saturated divalent cycloaliphatic group having from 6 to 14 carbon atoms. In a preferred embodiment, R is alkylene or arylene having up to 10 carbon atoms, or a saturated divalent cycloaliphatic group having from 6 to 10 carbon atoms. In a particularly preferred meaning, R is a radical derived from a diisocyanate, for example from hexane 1,6-diisocyanate, 1,6-trimethylhexane 1,6-diisocyanate, tetramethylene di-isocyanate, phenylene 1,4-diisocyanate, toluene 2,4-diisocyanate, toluene 2,6-diisocyanate, m- or p-tetramethylxylene di-isocyanate, di-isocyanate of isophorone, or cyclohexane 1,4-diisocyanate.

Aryl is a carbocyclic aromatic radical that is unsubstituted or is preferably substituted by lower alkyl or lower alkoxy. The examples are phenyl, tolyl, xylyl, methoxyphenyl, tertiary butoxy-phenyl, naphthyl, and phenanthryl. Arylene is preferably phenylene or naphthylene, which is unsubstituted or substituted by lower alkyl or lower alkoxy, in particular 1, 3-phenylene, 1,4-phenylene, or methyl-1,4-phenylene, 1,5-naphthylene, or 1, 8 -naffilene. A saturated divalent cycloaliphatic group is preferably cycloalkylene, for example cyclohexylene or cyclohexylene (lower alkyl), for example cyclohexylenemethylene, which is unsubstituted or substituted by one or more lower alkyl groups, for example methyl groups, for example trimethylcyclohexylenemethylene, for example the divalent isophorone radical. For the purposes of the present invention, the term "lower" in relation to radicals and compounds, unless defined otherwise, denotes, in particular, radicals or compounds having up to 8 carbon atoms, preferably having up to 4 carbon atoms. Lower alkyl has, in particular, up to 8 carbon atoms, preferably up to 4 carbon atoms, and is, for example, methyl, ethyl, propyl, butyl, tertiary butyl, pentyl, hexyl, or isohexyl. Alkylene has up to 12 carbon atoms, and can be straight or branched chain. Suitable examples are decylene, octylene, hexylene, pentylene, butylene, propylene, ethylene, methylene, 2-propylene, 2-butylene, 3-pentylene, and the like. Lower alkylene is alkylene having up to 8 carbon atoms, particularly preferably up to 4 carbon atoms. Particularly preferred meanings of lower alkylene are propylene, ethylene, and methylene. The arylene alkylene or arylene alkylene unit is preferably phenylene, unsubstituted or substituted by lower alkyl or lower alkoxy, and the alkylene unit thereof is preferably lower alkylene, such as methylene or ethylene, in particular methylene. Accordingly, these radicals are preferably phenylenemethylene or methylenephenylene. Lower alkoxy has, in particular, up to 8 carbon atoms, preferably up to 4 carbon atoms, and is, for example, methoxy, ethoxy, propoxy, butoxy, tertiary butoxy, or hexyloxy. Arylenenalkylene is preferably phenylene (lower alkylene) phenylene, which has up to 8 carbon atoms, in particular up to 4 carbon atoms in the alkylene unit, for example phenylene-ethylene-phenylene, or phenylene-methylene-phenylene. Some examples of preferred diisocyanates from which the divalent residues L are derived include trimethylhexamethylene di-isocyanate (TMHMDI), isophorone diisocyanate (IPDI), methylenediphenyl diisocyanate (MDI), and diisocyanate. 1,6-hexamethylene (HMDI). Blocks B can be monomeric, oligomeric, or polymeric. The molecular weights and chemical composition of each B block can be the same or different, provided they fall within the molecular weight scale specified above. Blocks B can be hydrophobic or hydrophilic, with the understanding that at least one of the blocks is of the formula (PFPE). Other suitable B blocks can be derived from poly (alkylene oxides). When one or more of the B blocks is hydrophilic, these blocks are derived in a particularly preferable manner from poly (alkylene oxides), more preferably from poly (lower alkylene oxides), and are more preferred from polyethylene glycols. It is more preferred that the B blocks are selected from blocks of the formula (PFPE) and poly (alkylene oxides), with the understanding that at least one of the blocks is of the formula (PFPE). In two highly preferred embodiments of the invention, there are two B blocks in a macromonomer of formula II which are both of the formula (PFPE), or one of which is of the formula (PFPE), while the other is derived from from a poly (alkylene oxide), preferably from a poly (lower alkylene oxide), and more preferably from polyethylene glycols. "Derivative from a poly (alkylene oxide)" in the context of the definition of blocks B, means that this block B differs from a poly (alkylene oxide) in that the two terminal hydrogens have been abstracted from that poly (alkylene oxide). In order to exemplify this, B denotes, if it is derived from a polyethylene glycol, - (OCH2CH2) aO-, where a is the index that indicates the number of repeating ethyleneoxy groups. The terminal group T is a univalent terminal group which is not polymerizable by free radicals, but which may contain other functionality. The preferred end groups are hydrogen, alkyl, substituted alkyl, aryl, or substituted aryl. The most preferred T groups are hydrogen, lower alkyl, and phenyl. Suitable substituents for Q or T can be selected from: alkyl, alkenyl, alkynyl, aryl, halogen, haloalkyl, haloalkenyl, haloalkynyl, haloaryl, hydroxy, alkoxy, alkenyloxy, aryloxy, haloalkoxy, haloalkenyloxy, haloaryloxy, amino, alkylamino, alkenylamino, alkynylamino, arylamino, acyl, aroyl, alkenylacyl, arylacyl, acylamino, alkylsulfonyloxy, arylsulfonyloxy, heterocyclyl, heterocyclyloxy, heterocyclylamino, haloheterocyclyl, alkoxycarbonyl, thioalkyl, alkylsulfonyl, thioaryl, arylsulfonyl, aminosulfonyl, dialkylamino, and dialkylsulfonyl, which They have up to 10 carbon atoms. The difunctional polymer from which M is derived contains a terminal functionality independently selected at each end, which can react with the precursor of the linking group L, such that a covalent bond is formed. The preferred terminal functionality is hydroxyl or amino. This functionality can be linked to the siloxane units in M by means of an alkylene group or other non-reactive spacer. Preferred terminal fractions are hydroxyalkyl, hydroxyalkoxyalkyl, and alkylamino. Especially preferred hydroxyalkyls are hydroxypropyl and hydroxybutyl; especially preferred hydroxyalkoxyalkyls are hydroxyethoxyethyl and hydroxyethoxypropyl. The preferred R1 and R2 groups are methyl. Preferred M residues in formula III as specified above, are of formula B: where n is an integer from 5 to 100; Alk is alkylene having up to 20 carbon atoms, uninterrupted or interrupted by oxygen; the radicals R, R2, R3, and R4, independently of one another, are alkyl, aryl, or alkyl substituted by halogen; and X3 is -O- or -NH-. In a preferred meaning, n is an integer from 5 to 70, in a particularly preferable manner from 8 to 50, in particular from 10 to 28. In a preferred meaning, the radicals R 1 R2, R3, and R4 are, independently of others, lower alkyl having up to 8 carbon atoms, particularly preferably lower alkyl having up to 4 carbon atoms, especially lower alkyl having up to 2 carbon atoms. A further particularly preferred embodiment of Rl r R2 > R3 'and R4' is methyl. Alkylene interrupted by oxygen is preferably lower alkylene-lower oxy-alkylene having up to 6 carbon atoms in each of the two lower alkylene fractions, more preferably lower alkylene-lower oxy-alkylene having up to 4 carbon atoms. carbon in each of the two lower alkylene fractions, the examples being ethylene-oxy-ethylene or ethylene-oxy-propylene. Alkyl substituted by halogen is preferably lower alkyl substituted by one or more, especially up to three halogens, such as fluorine, chlorine or bromine, the examples being trifluoromethyl, chloromethyl, heptafluorobutyl, or bromoethyl. A preferred macromonomer is of the formula I wherein n is on the scale of 2 to 5, L is a divalent residue (-C (O) -NH-R-NH-C (O) -) of a di-isocyanate, wherein R is alkylene, arylene, alkylenearylene, arylenealkylene, or arylenealkylene-arylene having up to 14 carbon atoms, or a saturated divalent cycloaliphatic group having from 6 to 14 carbon atoms, and Q is a compound of formula A in where P ^. is alkenyl of up to 4 carbon atoms, Y is -COO-, R 'is alkylene of up to 4 carbon atoms, X is -NHCOO-, and each of myp is 1. A preferred macromonomer of formula I is one in where n is on the scale from 2 to 5, L is a divalent residue derived from trimethylhexamethylene di-isocyanate (TMHMDI), and Q is the residue derived from isocyanatoethyl methacrylate. A preferred embodiment of this invention relates to a macromonomer of formula 1: CH2 = C (CH3) COOC2H4NHCO - (- PFPE-CONH-R-NHCO-) n.1-PFPE-CONHC2H4? COC (CH3) = CH2 (Formula 1) wherein PFPE is a perfluorinated polyether of the formula (PFPE) as defined herein, where x is on the scale of 8 to 10, e and is on the scale of 10 to 14, n > 1.0, and R is alkylene or arylene having up to 12 carbon atoms, or a saturated divalent cycloaliphatic group having from 6 to 14 carbon atoms.

In a preferred embodiment of the present invention, a macromonomer of formula 2 is provided: CH2 = C (CH3) COOC2H4NHCO - (- PFPE-CONH-R-NHCO-) n.? - PFPE-CONHC2H4? COC (CH3) - CH2 (Formula 2) wherein PFPE is a perfluorinated polyether of the formula (PFPE) as defined herein, n > 1.0, R is the trimethylhexamethylene component of TMHMDI, and where x is on the scale of 8 to 10, e and is on the scale of 10 to 14.

In a preferred embodiment of the present invention, macromonomers of the formula II corresponding to the formulas 3 to 6 are provided: CH2 = C (CH3) COOC2H4NHCO-PFPE-CONH-R-NHCO-PFPE-H (3) CH2 = C (CH3) COOC2H4NHCO-PEG-CONH-R-NHCO-PFPE-H (4) CH2 = C (CH3) COOC2H4NHCO-PFPE-CONH-R-NHCO-PEG-CH3 (5) CH2 = C (CH3) COOC2H4NHCO-PFPE-CONH-R-NHCO-PEG-H (6) where PFPE is of the formula (PFPE), where x and y are • as defined hereinbefore, R is alkylene, arylene, alkylenearylene, arylenealkylene, or arylenealkylene-arylene having up to 14 carbon atoms, or a saturated divalent cycloaliphatic group having from 6 to 14 carbon atoms, and PEG is drift from polyethylene glycol. Preferably, PEG has a molecular weight on the scale of 200 to 2,000 In a still more preferred embodiment of the present invention, macromonomers of formulas 7 to 10 are provided; CH2 = C (CH3) COOC2H4NHCO-PFPE-CONH-R-NHCO-PFPE-H (7) CH2 = C (CH3) COOC2H4NHCO-PEG-CONH-R-NHCO-PFPE-H (8) CH2 = C (CH3) COOC2H4NHCO-PFPE-CONH-R-NHCO-PEG-CH3 (9) CH2-C (CH3) COOC2H4NHCO-PFPE-CONH-R-NHCO-PEG-H (10) wherein PFPE is of the formula (PFPE), wherein x and y are as defined hereinabove, wherein R is the trimethylhexamethylene component of TMHMDI, and PEG is derived from polyethylene glycol. Preferably, PEG has a molecular weight on the scale of 200 to 2,000. It is also preferred in this embodiment that x is 10 and y is 12. A preferred macromonomer of formula III is one in which the molecular weight of the perfluorinated polyether is in the range of 800 to 4,000; L is the divalent residue derived from trimethylhexamethylene di-isocyanate (TMHMDI), and Q is the residue derived from isocyanatoethyl methacrylate. It is particularly preferred that the molecular weight of the perfluorinated polyether be about 2,000, and that the molecular weight of M be about 1,000. A preferred macromonomer of the present invention is of formula 11: CH2 = C (CH3) -COO-C2H4-NHCO-PFPE-CONH-R-NHCO- OCH2CH2CH2-Si (CH3) 2- (OSi (CH3) 2) 1 i-CH2CH2CH2O-CONH-R- (11) -NHCO -PFPE-CONH-C2H4-OCO-C (CH3) = CH2 wherein PFPE is of the formula (PFPE), and R is the trimethylhexamethylene component of TMHMDI (trimethylhexamethylene di-isocyanate), and wherein x is 10, e and is 12. The polymerizable component comprises at least one macromonomer that has when minus one perfluoropolyether unit. Other comonomers can be used to provide useful properties in the porous polymer, such as crosslinking agents and others of the macromonomers described above. Suitable comonomers can also include comonomers comprising one or more ethylenically unsaturated groups, which can enter a reaction to form a copolymer. It is preferred that the ethylenically unsaturated group is selected from the group consisting of acryloyl, methacryloyl, styryl, acrylamido, acrylamidoalkyl, urethane methacrylate, or any substituted derivatives thereof. Suitable comonomers include alkyl acrylates containing fluorine and silicon, and hydrophilic comonomers, which may be selected from the wide range of materials available to a person skilled in the art, and mixtures thereof. Particularly preferred comonomers include dihydroperfluoroalkyl acrylates, such as dihydroperfluoro-octyl acrylate and 1,1-dihydroperfluorobutyl acrylate, trihydroperfluoroalkyl acrylates, tetrahydroperfluoroalkyl acrylates, methacrylate or tris (trimethylsilyloxy) propyl acrylate, and comonomers containing amine, such as N, N-dimethylaminoethyl methacrylate, N, N-dimethyl acrylamide, and N, N-dimethylaminoethyl acrylamide. Other suitable comonomers may include a wide variety of macromonomers, such as vinyl terminated polymethyl methacrylate oligomers, and polydimethylsiloxanes terminated with ethylenically unsaturated groups. When used, it is preferred that the comonomers are present in the polymerization component in an amount of 1 to 60 weight percent of the polymerization component, more preferably 2 to 40 percent. The copolymers can be formed from mixtures of macromonomers of the formulas (I), (II), and (III), with or without other comonomers. Other macromonomers (monofunctional or difunctional) can also be incorporated with or without other comonomers. Optionally, a crosslinking agent, such as ethylene glycol dimethacrylate, can be added. When the polymerizable component comprises ethylenically unsaturated monomers, the polymerization can be initiated by ionizing radiation, photochemically or thermally, using a free radical initiator. It is preferred to use a free radical initiator such as benzoin methyl ether, Darocur, azobisisobutyronitrile, benzoyl peroxide, peroxydicarbonates, and the like. Particularly preferred photochemical free radical initiators are benzoin methyl ether and Darocur 1173 (trademark of Ciba-Geigy AG). Free radicals can be formed from the initiator by thermal or photochemical elements; You can also use initiation by reduction-oxidation. The porogens for use in the present invention may be selected from the range of optionally substituted (ie, unsubstituted or substituted) poly (alkylene) glycols, preferably those having up to 7 carbon atoms in each alkylene unit, which may be the same or different. Preferred are unsubstituted poly (alkylene) glycols. Preferably, the porogen is one or more of poly (lower alkylene) glycol, wherein the lower alkylene in this context denotes alkylene of up to 6 carbon atoms, preferably of up to 4 carbon atoms, in each alkylene unit. We have discovered that the porogens particularly preferred in the process of the present invention are polypropylene glycols. The porogens may be of a variable molecular weight, and are preferably of a molecular weight less than 4,000, still more preferably a molecular weight of less than 1,000. We have discovered that it is preferable that the porogen be liquid at room temperature. It is understood that the substituted poly (alkylene) glycols include poly (alkylene) glycols wherein one or two hydroxy groups have been replaced by an ether group, for example a lower alkoxy group, or an ester group, for example a carbonyl group - lower oxyalkyl, such that a substituted poly (alkylene) glycol can be preferably represented by a poly (alkylene) glycol monoether, a poly (alkylene) glycol diether, a glycol (alkylene) monoester, a poly (alkylene) glycol diester, or a poly (alkylene) glycol monoether-monoester. Although polypropylene glycol is particularly preferred, other polyalkylene glycols, such as polyethylene glycols, can also be used. The polymerizable component can be mixed with the porogen and other optional components, by any convenient means. For example, the polymerizable component can be mixed with the porogen and other optional components, by shaking or stirring. The order in which the components are added to the mixture is not too critical. The mixture may be in the form of a homogeneous solution, or may have the porogen as a distinct phase. Minor amounts of property modifying components may optionally be added to the mixture prior to polymerization. For example, solvents can be added. Suitable solvents include alcohols, amines or short chain ethers, as well as ethyl acetate, dimethyl formamide, water, and fluorinated alcohols. In most cases, these solvents are added to reduce the viscosity of the solution, or to make the solution easier to dose, for example in molds. Surfactants, preferably fluorinated surfactants, can be incorporated into the mixture. The use of surfactants is an effective means to control the size and density of pores. Nonionic surfactants containing fluorine are preferred. Particularly preferred surfactants include commercially available fluorinated surfactants, such as Zonyl (Du Pont) and Fluorad (3M). Zonyl FS300 (DuPont), which is made from a perfluorinated hydrophobic glue and a hydrophilic poly (ethylene oxide) head group, is a particularly preferred surfactant for use in the process of the present invention. Another type of compound that can act as a surfactant in the context of this invention is that of the macromonomers of formula II, as disclosed herein. These compounds are disclosed in greater detail in International Patent Application Number PCT / EP96 / 01256, whose pertinent disclosure, including their preferences, is incorporated herein. The mixture can be polymerized by any convenient method, generally as described above with reference to the initiation of the polymerizable component. Suitable polymerization conditions will be apparent to those skilled in the art. For example, temperatures can be from -100 ° C to 350 ° C, and pressures can be from less than atmospheric to higher than atmospheric. It will be understood that "a substantial proportion of the porogen remains in the form of a separate phase" means that there is sufficient porogen to form an interpenetrating network or a dispersion. The person skilled in the art will understand that, depending on the polymerization component and the porogen, a proportion of the porogen can be adsorbed or retained in the polymerization component, and eventually in the porous polymer. Normally more than 60 percent of the porogen is in the form of a separate phase immediately after polymerization. It is preferred that more than 80 percent of the porogen be in the form of a separate phase, more preferably more than 95 percent of the porogen is in the form of a separate phase. It is particularly preferred that the porogen forms an interpenetrating network in the polymerization component, resulting in the porous polymer having a cross-linked porous morphology. The crosslinked porous morphology may be an open cell sponge type structure consisting of interconnected polymeric globular particles, and may have an open cell structure with an array of generally spherical, interconnected pores. In another preferred embodiment, the porous polymer may be in the form of a closed cell structure with separate pores dispersed throughout the polymer. The porogen can be removed from the porous polymer by any convenient means. Suitable means for removing the polypeptide (or the solvent) include evaporation, solvent extraction, washing or leaching. The process of the present invention is useful for generating materials of different sizes and pore morphologies. The upper limit of the average pore size of the individual pores is about 5 microns, with 100 nanometers typical, while pores of about 10 nanometers in diameter can also be obtained. The pores can form an interpenetrating network. It is more useful to characterize these morphologies in terms of permeability to molecules of a defined molecular weight. This is described before the examples section. The morphology and porosity of the porous polymer can be controlled by altering the ratio of the porogen to the polymerizable monomer component. In high proportions of porogen, an open sponge-like structure consisting of interconnected polymeric globular particles is obtained. In lower proportions, a net of pores is obtained. In even lower proportions, a closed cell morphology is obtained. Particularly useful embodiments of the present method have the porogen phase in the form of a continuous interpenetrating network structure, which can be easily removed to leave a porous PFPE material having a network of pore lattices, allowing easy passage of the fluid and of the small diameter particles through the porous polymer. The size and density of the pores can be controlled by the ratio of the polymerizable component to the porogen.

Minor changes can be made by the use of surfactants as described hereinabove. The addition of a smaller proportion of water also increases the porosity. In another aspect, this invention provides a polymer (porous homopolymer or copolymer) containing perfluoropolyether as described above, when made by the process of this invention. As mentioned to some extent hereinabove, comonomers comprising one or more ethylenically unsaturated groups can be incorporated, which can enter a reaction to form a copolymer. It is preferred that the ethylenically unsaturated group is selected from the group consisting of acryloyl, methacryloyl, styryl, acrylamido, acrylamidoalkyl, or urethane methacrylate, or any substituted derivatives thereof. A comonomer used in this process can be hydrophilic or hydrophobic, or a mixture thereof. Suitable comonomers are, in particular, those that are normally used in the production of contact lenses and biomedical materials. A hydrophobic comonomer means a monomer that normally gives a homopolymer that is insoluble in water, and that can absorb less than 10 weight percent water. In an analogous manner, a hydrophilic comonomer means a monomer that normally gives a homopolymer that is soluble in water or that can absorb at least 10% by weight of water. Suitable hydrophobic comonomers are, without limitation, alkyl acrylates and methacrylates of 1 to 18 carbon atoms and cycloalkyl of 3 to 18 carbon atoms, acrylamides and alkyl methacrylamides of 3 to 18 carbon atoms, acrylonitrile, methacrylonitrile, alkanoates from 1 to 18 carbon atoms of vinyl, alkenes of 2 to 18 carbon atoms, haloalkenes of 2 to 18 carbon atoms, styrene, (lower alkyl) styrene, vinyl ethers of lower alkyl, acrylates and perfluoroalkyl methacrylates of 2 to 10 carbon atoms, and the corresponding partially fluorinated acrylates and methacrylates, perfluoroalkyl acrylates and methacrylates of 3 to 12 carbon atoms-thioethylcarbonylaminoethyl, acryloxy- and methacryloxy-alkylsiloxanes, N-vinylcarbazole, alkyl esters of 1 to 12 carbon atoms, of maleic acid, fumaric acid, itaconic acid, mesaconic acid, and the like. Preference is given, for example, to acrylonitrile, to alkyl esters of 1 to 4 carbon atoms of vinyl unsaturated carboxylic acids having 3 to 5 carbon atoms, or vinyl esters of carboxylic acids having up to 5 carbon atoms. Examples of suitable hydrophobic comonomers are methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl acrylate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl valerate, styrene, chloroprene, vinyl chloride, vinylidene chloride, acrylonitrile, 1-butene, butadiene, methacrylonitrile, vinyltoluene, vinylethyl ether, perfluorohexyl-thioethylcarbonylaminoethyl methacrylate, methacrylate of isobornyl, trifluoroethyl methacrylate, hexafluoroisopropyl methacrylate, hexafluorobutyl methacrylate, tris-trimethylsilyloxysilylpropyl methacrylate (hereinafter: Tris methacrylate), tris-trimethylsilyloxysilylpropyl acrylate (hereinafter: Tris acrylate), 3-methacryloxypropylpenta -methyldisiloxane and bis (methacryloxypropyl) tetramethyldisiloxane. Preferred examples of the hydrophobic comonomers are methyl methacrylate, Tris acrylate, Tris methacrylate, and acrylonitrile. Suitable hydrophilic comonomers are, without this list being exhaustive, lower alkyl acrylates and methacrylates substituted by hydroxyl, acrylamide, methacrylamide, acrylamides and methacrylamides of (lower alkyl), ethoxylated acrylates and methacrylates, acrylamides and methacrylamides of (lower alkyl) substituted by hydroxyl, vinyl ethers of lower alkyl substituted by hydroxyl, sodium vinyl sulphonate, styrenic sodium sulfonate, 2-acrylamido-2-methylpropanesulfonic acid, N- vinylpyrrole, N-vinyl 2-pyrrolidone, 2-vinyloxazoline, 2-vinyl-4,4'-dialkyl-oxazolin-5-one, 2- and 4-vinylpyridine, vinyl unsaturated carboxylic acids having a total of 3 to 5 atoms of carbon, amino acrylates and methacrylates (lower alkyl) (wherein the term "amino" also includes quaternary ammonium), mono (lower alkyl-amino) (lower alkyl), and di (lower alkyl-amino) (lower alkyl) , allyl alcohol, and the like. Preference is given, for example, to N-vinyl 2-pyrrolidone, acrylamide, methacrylamide, hydroxyl-substituted lower alkyl acrylates and methacrylates, hydroxyl-substituted (lower alkyl) acrylamides and methacrylamides, and vinyl unsaturated carboxylic acids having a total of 3 to 5 carbon atoms. Examples of suitable hydrophilic comonomers are hydroxyethyl methacrylate (HEMA), hydroxyethyl acrylate, hydroxypropyl acrylate, trimethyl ammonium 2-hydroxypropyl methacrylate hydrochloride (Blemer® QA, for example from Nippon Oil), dimethylaminoethyl methacrylate (DMAEMA). , (meth) acrylamide dimethylaminoethyl, acrylamide, methacrylamide, N, N-dimethyl acrylamide (DMA), allyl alcohol, vinylpyridine, glycerol methacrylate, N- (1, l-dimethyl-3-oxobutyl) acrylamide, 2-pyrrolidone N- vinyl (NVP), acrylic acid, methacrylic acid, and the like. Preferred hydrophilic comonomers are trimethyl ammonium 2-hydroxypropyl methacrylate hydrochloride, 2-hydroxyethyl methacrylate, dimethylaminoethyl methacrylate, trimethyl ammonium 2-hydroxypropyl methacrylate hydrochloride, N, N-dimethyl acrylamide, and 2-pyrrolidone N- vinyl As mentioned hereinabove, suitable comonomers include alkyl acrylates containing fluorine and silicon, and hydrophilic comonomers, which may be selected from a wide range of available materials, and mixtures thereof. Particularly preferred comonomers include dihydroperfluoroalkyl acrylates, such as dihydroperfluoro-octyl acrylate and 1,1-dihydroperfluorobutyl acrylate, trihydroperfluoroalkyl acrylates, tetrahydroperfluoroalkyl acrylates, methacrylate or tris (trimethylsilyloxy) propyl acrylate, and comonomers which containing amine, such as N, N-dimethylaminoethyl methacrylate, N, N-dimethyl acrylamide and N, N-dimethylaminoethyl acrylamide. The preferred range for the addition of the individual comonomers in the formulation is from 0 to 60 weight percent, and more preferably from 0 to 40 weight percent of the formulation. Mixtures of macromonomers of the formula I, II, or III can also be used to make suitable copolymers with or without other comonomers. If desired, a polymer network can be reinforced by the addition of a crosslinking agent, for example a poly-unsaturated crosslinking comonomer. In this case, the term "cross-linked polymers" is used. Accordingly, the invention further relates to a process for the production of a crosslinked polymer comprising the polymerization product of a macromer of the formula (I), (II), or (III), if desired with at least a vinyl comonomer and with at least one crosslinking comonomer. Examples of typical crosslinking comonomers are allyl (meth) acrylate, lower alkylene glycol di (meth) acrylate, poly (lower alkylene) glycol di (meth) acrylate, lower alkylene di (meth) acrylate, ether divinyl, divinyl sulfone, di- and tri-vinylbenzene, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, bisphenol A di (meth) acrylate, methylene bis (meth) acrylamide, triallyl phthalate and diallyl phthalate. If a crosslinking comonomer is used, the amount used is on the scale of 0.05 to 20 percent of the total expected weight of the polymer, preferably the comonomer is on the scale of 0.1 to 10 percent, and more preferably on the scale of 0.1 to 2 percent. According to a further aspect of the present invention, there is provided an ophthalmic device, preferably a contact lens, and still more preferably a soft contact lens made from the porous polymers or copolymers as described hereinabove. Contact lenses, and also soft contact lenses, are polymeric discs with surfaces of different radii of curvature. The spokes are selected in combination with the refractive index of the polymer, such that the desired optical correction is obtained, and that the inner surface of the lens is coupled to the contour of the user's cornea. They are usually sold in sterile serum. Optionally, the lens surface can be modified by coating, employing procedures well known in the art, such as plasma polymerization, gloss discharge, or grafting of a more hydrophilic polymer. By way of example, the process can be used in the manufacture of articles, such as ophthalmic devices, preferably contact lenses. In that case, the appropriate amounts of polymerizable monomers, solvent (if required), and photoinitiator are mixed together to form a polymerization mixture. Then the polymerization mixture is flooded with nitrogen, and the amount required in the concave half of a polypropylene mold is dosed. The mold is closed and fastened, and the assembly is placed in an ultraviolet irradiation cabinet equipped with ultraviolet lamps. The irradiation is carried out for the required time, and then the halves of the mold are separated. The polymerized lens is extracted in an appropriate solvent (for example, a mixture of isopropyl acetate or tertiary butyl / fluorinated solvent). Then the solvent is extensively exchanged with an alcohol (for example isopropyl alcohol), and subsequently with serum, to give the lens product. The polymers produced according to the present invention can be formed into other useful articles employing conventional molding and processing techniques, as are well known in the art. Given the visual transparency of the polymers of the present invention, they can find use in tissue culture apparatus, optical instruments, microscope slides, and the like. A further aspect of this invention is the use of the porous perfluoropolyether in the form of a film or sheet, such as a membrane or a filter. This porous PFPE film can be laminated with another support film to form a composite. These applications may involve gas or liquid permeability. The porous polymers of the present invention may be suitable, for example, for use in the fields of membrane filters and separation, in the field of industrial biotechnology, and in the biomedical field. The examples for the field of membrane filters and separation are industrial membranes, for example for micro-filtration and ultra-filtration, for example in the food, dairy, juice or low-alcohol beer industries; wastewater treatment, in reverse osmosis, or membrane distillation using osmotic pressure.

Examples for the field of industrial biotechnology are supports for synthetic and biological ligands, or receptors for bioreactors and biosensors, sustained release devices for active compounds, or capacitors. Examples for the biomedical field are ophthalmic devices, for example contact lenses or artificial corneas, dialysis and blood filtration, encapsulated biological implants, for example pancreatic islets, implanted glucose monitors, patches and drug delivery devices, bandages and healed of wounds, artificial skin, vascular grafts, regenerative templates or patches for wound healing, tissue augmentation (soft), percutaneous fixation devices, or artificial organs. Throughout this specification and the following claims, unless the context requires otherwise, it will be understood that the word "comprise", or variations such as "comprises", or "comprising", implies inclusion of an integer or group of integers mentioned, but not the exclusion of any other integer or group of integers. A generally applicable method for handling the porous polymers, once polymerized, is, for example, as follows: The polymers are removed from the mold and passed through a general extraction and drying procedure to remove any unpolymerized components. This procedure consists of a 4 hour soak in a fluorinated solvent (PF5060 from 3M Corporation), then a 16 hour immersion in isopropyl acetate, and a subsequent immersion for 4 hours in isopropyl alcohol. After drying under vacuum, the polymer becomes white. When the white polymer undergoes a change of graduated solvent, starting from ethanol, 75 percent ethanol / water, 50 percent ethanol / water, 25 percent ethanol / water, and then pure water or serum, becomes transparent . The change of graduated solvent has the effect of introducing water into the porous channels of the porous PFPE materials; this occurs despite the highly hydrophobic nature of the PFPE-based materials. In the examples of this specification, the Macromonomer (1) is a perfluorinated vinyl terminated macromer of the formula: CH2 = C (CH3) COOC2H4NHCO-PFPE-CONHC2H4? COC (CH3) = CH2 wherein PFPE is the perfluorinated polyether component of 3M Experimental Product L-12875, which is a mixture of perfluorinated polyethers of the formula: -OCH2CF2O (CF2CF2O) x (CF20) and CF2CH20- where the units of CF2CF20 and CF20 can be distributed in a random way, or they can be distributed as blocks throughout the chain, and where x is on the scale of 8 to 10, and is on the scale of 10 to 14. The present invention is further described in the following non-limiting examples. If not specified otherwise, all parts are by weight. The temperatures are in degrees Celsius. The molecular weights of the macromers or polymers are number average molecular weights if not otherwise specified. The following methods are used: Measurement of water content; The percentage of water content (weight / weight) of the porous polymers was determined by comparing the hydrated and dehydrated weight of the polymers. The polymers were first dried overnight in a vacuum oven (0.1 mmHg) at 37 ° C, and then weighed on cooling. The hydration was achieved by means of a graduated solvent exchange process. The dried polymer disks are soaked in the following solutions per shift, passing 1/2 hour in each solution before the solvent is changed to the next one. For every 10 polymer discs, 60 milliliters of solvent was used. 1. 100% ethanol 2. 75% ethanol / water 3. 50% ethanol / water 4. 25% ethanol / water 5. 100% water.

The polymers are allowed to equilibrate overnight in water or to a constant weight - the equilibrium times for the hydrophilic polymers can be greater than 16 hours. The hydrated polymers are placed on Kimwipes fine grade lint-free paper (Kimberly-Clark) to dry excess surface moisture, and finally weighed as the hydrated weight. hydrated weight - dry weight% water content = -__ x 100 hydrated weight Permeability measurement Method A: Supervision of permeability by utraviolet spectroscopy. Permeating: Bovine Serum Albumin (BSA, Molecular Weight = 67, 000). Concentration of Bovine Serum Albumin = 8 milligrams / milliliter in phosphate regulated serum (PBS), Phosphate Regulated Serum = 20 mM Phosphate in 0.2 M sodium chloride, pH = 7.4. The porosity of the synthetic polymers was investigated using a static diffusion cell (ie, the solutions are not stirred). This method involves fixing a hydrated flat polymer disk of 20 millimeters in diameter (see measurements of the water content to know the hydration process) between two chambers that are separated by a ring • O 'of rubber with an internal diameter of 7.5 centimeters . Each chamber contains a volume of approximately 2.2 milliliters. One chamber contains a solution of 8 milligrams / -mililiter of bovine serum albumin in serum regulated with phosphate, while the other chamber is filled only with phosphate-regulated serum. At selected time intervals, the samples are removed from the phosphate-buffered chamber, using a glass pipette, and the ultraviolet absorbance of the solution is measured at 280 nanometers (A280). This determines whether any bovine serum albumin has been diffused through the polymer disk. Accordingly, the higher absorbance reading points for a higher rate of diffusion of bovine serum albumin indicate a structure with a relatively large pore size and / or a larger pore density.

Method B A more quantitative measurement of permeability to bovine serum albumin was established, using a device in which the flat sample of 20 millimeters in diameter was fixed between two chambers where the solutions of bovine / serum serum albumin were being stirred. regulated with phosphate, and of serum regulated with phosphate, at speeds higher than 200 rpm. The purpose of the agitation was to overcome the resistance to mass transfer that exists predominantly in the surface boundary layer of a porous material. This method was used to measure the permeability of polymer disks to glucose, inulin, and bovine serum albumin labeled with I 125. Permeability is measured in relation to commercial etched polycarbonate membranes (trade name of Poretics), with pore sizes of 50 nanometers and 25 nanometers.

Example 1: The following formulation was placed in polypropylene lens molds, and polymerized for 3 hours under the irradiation generated from an ultraviolet lamp at a wavelength of 365 nanometers. All parts are in weight.

PPG-725 is poly (propylene glycol) with a molecular weight of 725. The permeability of the lenses to a solution of bovine serum albumin was monitored by ultraviolet spectroscopic technique. After 21 hours, the absorbance reading of the phosphate-buffered saline solution initially free of protein was A280 = 0.066, and this was increased to -80 0.117 after 44 hours.

Example 2: The following formulation was placed in polypropylene molds for polypropylene lenses (0.2 millimeters thick, 20 millimeters in diameter), and polymerized for 3 hours under the irradiation generated from an ultraviolet lamp at a wavelength of 365 nanometers All parts are in weight.

The permeability of the lenses to a solution of bovine serum albumin was monitored by ultraviolet spectroscopic technique. After 24 hours, the absorbance reading for lens A was A280 = 0.28. After hydration, the water content of lens A was measured at 31.8 percent (w / w). The preparation of porous polymers from Formulation A was equally successful when the isopropanol was replaced by other common organic solvents, such as ethanol, ethyl acetate, and dimethyl formamide.

Example 3: The following formulations were placed in polypropylene molds for polypropylene lenses (0.2 millimeters thick, 20 millimeters in diameter), and polymerized for 3 hours under the irradiation generated from an ultraviolet lamp at a wavelength of 365 nanometers All parts are in weight.

The permeability of the lenses to a solution of bovine serum albumin was monitored by ultraviolet spectroscopic technique. After 21 hours, the absorbance reading for lens A was A280 = 0.364, and for lens B it was 280 = 0.05.

Example B is a control sample that shows that the protein permeability observed in Example A was due to the addition of PPG.

Example 4: The following formulation was placed in polypropylene lens molds (0.2 millimeters thick, 20 millimeters in diameter), and polymerized for 3 hours under the irradiation generated from an ultraviolet lamp at a wavelength of 365 nanometers . All parts are in weight.

The permeability of the lenses to a solution of bovine serum albumin was monitored by ultraviolet spectroscopic technique. After 24 hours, the absorbance reading for lens A was A280 = 0.277. After hydration, the water content of lens A was measured at 32 percent (w / w).

Example 5: The following formulation was placed in polypropylene lens molds (0.2 millimeters thick, 20 millimeters in diameter), and polymerized for 3 hours under the irradiation generated from an ultraviolet lamp at a wavelength of 365 nanometers . All parts are in weight.

The permeability of the lenses to a solution of bovine serum albumin was monitored by ultraviolet spectroscopic technique. After 24 hours, the absorbance reading for lens A was A280 = 0.210. After hydration, the water content of lens A was measured at 36 percent (weight / weight).

Example 6: The following formulation was placed in polypropylene molds for polypropylene lenses (0.2 millimeters thick, 20 millimeters in diameter), and polymerized for 3 hours under the irradiation generated from an ultraviolet lamp at a wavelength of 365 nanometers All parts are in weight.

The permeability of the lenses to a solution of bovine serum albumin was monitored by ultraviolet spectroscopic technique. After 24 hours, the absorbance reading for lens A was A280 = 0.17. After hydration, the water content of lens A was measured at 36 percent (w / w).

Example 7: The following formulations were placed in polypropylene lens molds (0.2 millimeters thick, 2 millimeters in diameter), and polymerized for 3 hours under the irradiation generated from an ultraviolet lamp at a wavelength of 365 nanometers. All parts are, by weight.

The permeability of the lenses to a solution of bovine serum albumin was monitored by ultraviolet spectroscopic technique. After 24 hours, the absorbance reading for lens A was A280 = 0.22, and for lens B was A280 = 0.46. After hydration, the water content of lenses A and B were measured at 36 and 47 percent (w / w), respectively. It is noted that the increase in the level of PPG-425 in formulation B has produced a polymer with a higher water content and a higher permeability to bovine serum albumin.

Example 8: The following formulations were placed in polypropylene lens molds (0.2 millimeters thick, 20 millimeters in diameter), and polymerized for 3 hours under the irradiation generated from an ultraviolet lamp at a wavelength of 365 nanometers . All parts are in weight.

The permeability of the lenses to a solution of bovine serum albumin was monitored by ultraviolet spectroscopic technique. After 24 hours, the absorbance reading for lens A was A280 = 0.17, and for lens B it was A280 = 0.32. After hydration, the water content of lenses A and B were measured at 35 and 41 percent (w / w), respectively. It is noted that the increase in the level of PPG-425 in formulation B has produced a polymer with a higher water content and a higher permeability to bovine serum albumin.

Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It should be understood that the invention includes all variations and modifications that fall within its spirit and scope.

Claims (7)

1. A process for producing a porous polymer, which comprises the steps of: 1) dispersing a porogen in a continuous phase of monomer component, wherein the continuous phase of monomer component comprises at least one monomer having at least one perfluoropolyether unit, and wherein the porogen is an optionally substituted poly (alkylene) glycol; 2) then, polymerize the continuous monomeric phase; Y 3) remove the porogen from the porous polymer.

2. A process according to claim 1, wherein the porogen is an unsubstituted poly (alkylene) glycol.

3. A process according to claim 1, wherein the porogen is a polypropylene glycol.

4. A process according to claim 1, wherein the porogen is a polypropylene glycol with a molecular weight of less than 1000.

5. A porous polymer comprising perfluoropolyether units, prepared according to the process described in claim 1.

6. The use of the porous polymer comprising perfluoropolyether units according to claim 5, in the form of a film or sheet, such as a membrane or a filter. The use of the porous polymer comprising perfluoropolyether units according to claim 5, as an ophthalmic device, such as a contact lens or an artificial cornea.