Vinylidene fluoride copolymers

1. A linear semi-crystalline copolymer [polymer (A)] comprising recurring units derived from vinylidene fluoride (VDF) monomer and at least one hydrophilic (meth)acrylic monomer (MA) of formula:

wherein each of R1, R2, R3, equal to or different from each other, is independently an hydrogen atom or a C 1 -C 3 hydrocarbon group, and R OH is a hydrogen or a C 1 -C 5 hydrocarbon moiety comprising at least one hydroxyl group,

said polymer (A) comprising from 0.05 to 10% by moles of recurring units derived from said hydrophilic (meth)acrylic monomer (MA) and being characterized by a fraction of randomly distributed units (MA) of at least 40%.

2. The polymer (A) of claim 1 , wherein the monomer (MA) is selected from the group consisting of:

hydroxyethylacrylate (HEA) of formula:

2-hydroxypropyl acrylate (HPA) of either of formulae:

acrylic acid (AA) of formula:

and mixtures thereof.

3. The polymer (A) of claim 1 , wherein the fraction of randomly distributed units (MA) is of at least 50%.

4. The polymer (A) of claim 1 , comprising at least 0.1% moles of recurring units derived from said hydrophilic (meth)acrylic monomer (MA).

5. The polymer (A) of claim 1 , comprising at most 7.5% moles of recurring units derived from said hydrophilic (meth)acrylic monomer (MA).

6. The polymer (A) claim 1 , undergoing a loss in weight of 1 wt in TGA analysis under nitrogen following ISO 11358 standard at a temperature of more than 350° C.

7. A process for the manufacture of linear semi-crystalline copolymers according to claim 1 , said process comprising polymerizing in an aqueous medium in the presence of a radical initiator the vinylidene fluoride monomer and the hydrophilic (meth)acrylic monomer (MA) in a reaction vessel, said process comprising

continuously feeding an aqueous solution comprising hydrophilic (meth)acrylic monomer (MA); and

maintaining the pressure in said reactor vessel exceeding the critical pressure of the vinylidene fluoride.

8. A composition (C) comprising the polymer (A) according to claim 1 and at least one VDF polymer comprising at least 70% moles of recurring units derived from VDF and, optionally, up to 30% moles of recurring units derived from at least one other suitable fluorinated comonomer.

9. The composition (C) of claim 8 wherein the at least one other suitable fluorinated comonomer is selected from the group consisting of hexafluoropropylene, chlorotrifluoroethylene, and trifluoroethylene.

10. An electrode-forming composition comprising polymer (A) according to claim 1 , a powdery electrode material and, optionally, an electroconductivity-imparting additive and/or a viscosity modifying agent.

11. The electrode-forming composition of claim 10 , comprising:

(a) polymer (A), in an amount from 1 to 10% wt with respect to the total weight (a)+(b)+(c);

(b) carbon black as electroconductivity-imparting additive, in an amount from 2 to 10% wt-with respect to the total weight (a)+(b)+(c);

(c) a powdery electrode material in an amount from 80 to 97% wt.

12. A method for forming electrodes of Lithium batteries and/or electric double layer capacitors, comprising using the linear semi-crystalline copolymers of claim 1 .

13. A method for the manufacture of hydrophilic membranes, comprising using the linear semi-crystalline copolymers of claim 1 .

14. A hydrophilic membrane comprising the linear semi-crystalline copolymers of claim 1 .