The present invention relates to a compound of formula (I) below: ##STR00001##
in which: R.sub.1 represents, in particular, an alkylene group comprising from 1 to 6 carbon atoms; R.sub.2 and R.sub.3 are, in particular, H; n is 0, 1, 2 or 3; and R.sub.4 is chosen from the group consisting of: NO.sub.2, OR.sub.a, SR.sub.a and NR.sub.aR.sub.b, wherein R.sub.a and R.sub.b are as defined above; R.sub.5 and R.sub.6, identical or different, represent an alkyl or alkoxy group comprising from 1 to 6 carbon atoms; and R.sub.7, R.sub.8 and R.sub.9, identical or different, represent an alkyl group comprising from 2 to 6 carbon atoms.

Disclosed herein are isotactic polyvinyl ethers and improved methods of making same. The method disclosed herein can produce polyvinyl ethers having a higher isotacticity as compared to polyvinyl ethers prepared with conventional methods.

Cyclopentene monomers and methods of polymerization, including the polymerization of the cyclopentene monomers. The cyclopentene monomers include allylic substituted cyclopentene monomers that may be racemic or enantiopure. The methods of polymerization may permit the resulting polymers to have one or more desirable structural features.

To provide a polymer capable of forming a polymer electrolyte membrane that is resistant to breakage even when being repeatedly subjected to humidification and drying or a catalyst layer that is resistant to formation of cracks; a polymer electrolyte membrane employing said polymer; and a membrane/electrode assembly for a polymer electrolyte fuel cell. A polymer comprising units (u1) having two ion-exchange groups and units (u2) of e.g. a perfluoro(alkyl vinyl ether), wherein the molar ratio (u2)/((u1)+(u2)) is more than 0.30 and at most 0.70. A membrane/electrode assembly 10 comprising an anode 13 having a catalyst layer 11 and a gas diffusion layer 12, a cathode 14 having a catalyst layer 11 and a gas diffusion layer 12, and a polymer electrolyte membrane 15 disposed between the anode 13 and the cathode 14 in a state of being contact with the catalyst layers 11, wherein either one or each of the catalyst layers 11 and the polymer electrolyte membrane 15 contains the aforementioned polymer.

To provide a polymer capable of forming a polymer electrolyte membrane that is resistant to breakage even when being repeatedly subjected to humidification and drying or a catalyst layer that is resistant to formation of cracks; a polymer electrolyte membrane employing said polymer; and a membrane/electrode assembly for a polymer electrolyte fuel cell. A polymer comprising units (u1) having two ion-exchange groups and units (u2) of e.g. a perfluoro(alkyl vinyl ether), wherein the molar ratio (u2)/((u1)+(u2)) is more than 0.30 and at most 0.70. A membrane/electrode assembly 10 comprising an anode 13 having a catalyst layer 11 and a gas diffusion layer 12, a cathode 14 having a catalyst layer 11 and a gas diffusion layer 12, and a polymer electrolyte membrane 15 disposed between the anode 13 and the cathode 14 in a state of being contact with the catalyst layers 11, wherein either one or each of the catalyst layers 11 and the polymer electrolyte membrane 15 contains the aforementioned polymer.

The present invention relates to a compound of formula (I) below:

##STR00001##

in which:

R.sub.1 represents, in particular, an alkylene group comprising from 1 to 6 carbon atoms;

R.sub.2 and R.sub.3 are, in particular, H;

n is 0, 1, 2 or 3; and R.sub.4 is chosen from the group consisting of: NO.sub.2, OR.sub.a, SR.sub.a and NR.sub.aR.sub.b, wherein R.sub.a and R.sub.b are as defined above;

R.sub.5 and R.sub.6, identical or different, represent an alkyl or alkoxy group comprising from 1 to 6 carbon atoms; and

R.sub.7, R.sub.8 and R.sub.9, identical or different, represent an alkyl group comprising from 2 to 6 carbon atoms.

The present invention relates to a compound of formula (I) below:

##STR00001##

in which:

R.sub.1 represents, in particular, an alkylene group comprising from 1 to 6 carbon atoms;

R.sub.2 and R.sub.3 are, in particular, H;

n is 0, 1, 2 or 3; and R.sub.4 is chosen from the group consisting of: NO.sub.2, OR.sub.a, SR.sub.a and NR.sub.aR.sub.b, wherein R.sub.a and R.sub.b are as defined above;

R.sub.5 and R.sub.6, identical or different, represent an alkyl or alkoxy group comprising from 1 to 6 carbon atoms; and

R.sub.7, R.sub.8 and R.sub.9, identical or different, represent an alkyl group comprising from 2 to 6 carbon atoms.

The polymeric dispersant is a copolymer obtainable by copolymerizing at least a first monomer chosen from a maleimide compound and maleic anhydride, and a second monomer being an ethylenically unsaturated monomer and in case of maleic anhydride, conversion of resulting maleic anhydride units to N-substituted maleimide units, wherein the first monomer comprises a first substituent having a substantially non-polar chain and wherein the second monomer comprises a second, more polar substituent. In one embodiment of the copolymerisation method, first and second monomers are used with copolymerisation parameters r1, r2, such that r1 and r20.5. This results in an at least moderately alternating copolymer. The conversion of maleic anhydride units to maleimide may be partial, for instance at least 10%. The polymeric dispersant can be used in an ink dispersion further comprising colorant particles and an aqueous and/or alcoholic carrier liquid.

The polymeric dispersant is a copolymer obtainable by copolymerizing at least a first monomer chosen from a maleimide compound and maleic anhydride, and a second monomer being an ethylenically unsaturated monomer and in case of maleic anhydride, conversion of resulting maleic anhydride units to N-substituted maleimide units, wherein the first monomer comprises a first substituent having a substantially non-polar chain and wherein the second monomer comprises a second, more polar substituent. In one embodiment of the copolymerisation method, first and second monomers are used with copolymerisation parameters r1, r2, such that r1 and r20.5. This results in an at least moderately alternating copolymer. The conversion of maleic anhydride units to maleimide may be partial, for instance at least 10%. The polymeric dispersant can be used in an ink dispersion further comprising colorant particles and an aqueous and/or alcoholic carrier liquid.

The polymeric dispersant is a copolymer obtainable by copolymerizing at least a first monomer chosen from a maleimide compound and maleic anhydride, and a second monomer being an ethylenically unsaturated monomer and in case of maleic anhydride, conversion of resulting maleic anhydride units to N-substituted maleimide units, wherein the first monomer comprises a first substituent having a substantially non-polar chain and wherein the second monomer comprises a second, more polar substituent. In one embodiment of the copolymerisation method, first and second monomers are used with copolymerisation parameters r1, r2, such that r1 and r20.5. This results in an at least moderately alternating copolymer. The conversion of maleic anhydride units to maleimide may be partial, for instance at least 10%. The polymeric dispersant can be used in an ink dispersion further comprising colorant particles and an aqueous and/or alcoholic carrier liquid.