Polymer compositions

1. A polymer precursor represented by Formula 1a

in which

Y represents a direct bond or an oxy group;

R 1 represents an optionally substituted organo group with at least one double bond wherein the double bond is optionally an activated unsaturated moiety such as a (meth) acrylate group;

R 2 and R 3 within each optional repeat unit, are independently chosen from one or more optionally substituted hydrocarbo, hydrocarbo(oxy), hydrosilico and/or hydrosilico(oxy) group(s);

R 4 is an optionally substituted organo group having at least one double bond as defined for R 1 above;

n is from about 0 to about 2000;

with the proviso that the polymer precursor(s) are other than those composed of a polysiloxane main chain and at least one block of polymerised unsaturated monomers obtained by reacting at least one polysiloxane containing pre-polymer containing at least one transferable group with ethylenically unsaturated monomers in a controlled free radical additional polymerisation.

2. A process for preparing a polymeric composition suitable for use as a pressure sensitive adhesive, flow modifier and/or defoaming agent from one or more reactive silicon containing polymer precursor(s) represented by Formula 1b:

in which:

Y represents a direct bond or an oxy group;

R 1 represents an optionally substituted organo group with at least one double bond wherein the double bond is optionally an activated unsaturated moiety such as a (meth) acrylate group;

R 2 and R 3 within each optional repeat unit, are independently chosen from one or more of an optionally substituted hydrocarbo, hydrocarbo(oxy), hydrosilico and/or hydrosilico(oxy) group(s);

R 4 is an optionally substituted organo group having at least one double bond as defined for R 1 above;

n is from about 0 to about 2000.

the process comprising the step of: polymerising at least one polymer precursor of Formula 1b by a suitable means chosen from one or more of thermally, actinically, radically, and ionically induced polymerization.

3. The process of claim 2 , in which the polymer precursor(s) of Formula 1b are polymerised together with at least one other silicon free co-polymer precursor(s).

4. A process for the preparation of a polymeric composition comprising subjecting at least one polymer precursor of Formula 1a as claimed in claim 1 to thermally, actinically, radically, or ionically induced polymerisation.

5. A polymeric composition comprising polymer molecules having moieties derived from at least one polymer precursor of claim 1 .

6. A polymeric composition obtained by the process as claimed in claim 2 .

7. A polymeric composition as claimed in claim 5 , comprising polymer molecules having moieties derived from at least one polymer precursor of claim 1 and moieties derived from at least one vinyl type monomer which does not comprise silicon atoms or silicon groups.

8. The polymeric composition of claim 5 , where the mass fraction of silicon in the polymeric composition is from 0.001% to 50%.

9. The polymeric composition of claim 5 , wherein the weight-average molar mass of the polymeric composition is from 10 kg/mol to 250 kg/mol.

10. A polymeric flow modifier composition (flow modifier) comprising a polymer as claimed in claim 5 .

11. A method for improving the flow properties of coating compositions, the method comprising adding a flow modifier according to claim 10 to a liquid or to a mixture of liquids to form a coating composition, and coating a suitable substrate such that the composition forms a coating having substantially even surface thereon.

12. A coating composition that forms an even surface when coated onto a substrate, comprising a flow modifying amount of a flow modifier as claimed in claim 10 .

13. A polymeric anti-foaming agent composition (defoamer) comprising a polymer as claimed in claim 5 .

14. A method for inhibiting foam in fluid compositions that have a tendency to foam, the method comprising adding a foam-inhibiting amount of a defoamer according to claim 13 to a liquid or to a mixture of liquids to form the fluid composition.

15. A composition resistant to foaming comprising a fluid having a tendency to foam and having dispersed therein a foam-inhibiting amount of a defoamer as claimed in claim 13 .

16. A polymeric pressure sensitive adhesive composition (PSA) comprising the polymer as claimed in claim 5 .

17. A PSA comprising an effective amount of a PSA composition as claimed in claim 16 .

18. A method of using the PSA composition of claim 16 comprising adding the PSA to a liquid or a mixture of liquids to form a liquid mixture, and applying the liquid mixture to a surface of a substrate.

19. A substrate and/or laminate coated with the PSA composition of claim 16 .

20. The process of claim 3 , wherein the at least one silicon free co-polymer precursor is a (meth)acrylate monomer.

21. The process of claim 4 , wherein the polymerization step is optionally performed in the presence of at least one vinyl type monomer that does not comprise silicon atoms or groups.

22. A polymeric flow modifier composition obtained by the process according to claim 3 .

23. A polymeric anti-foaming agent composition obtained according to the process of claim 2 .

24. A polymeric pressure sensitive adhesive composition obtained by the process according to claim 2 .

25. A substrate according to claim 19 , wherein the substrate is chosen from polymer film and paper.