Ultra pure rubber

1. A copolymer composition having a copolymer content of 98.5% or more;

wherein the copolymer is a copolymer of at least one isoolefin monomer and at least one multiolefin monomer, and the composition further comprises at least one LCST compound in an amount of 1 ppm to 5,000 ppm.

2. A copolymer composition comprising:

I) 100 parts by weight of a copolymer wherein the copolymer is a copolymer of at least one isoolefin monomer and at least one multiolefin monomer;

II) 0.0001 to 0.5 parts by weight of a least one lower critical solution temperature (LCST) compound;

III) no or 0.0001 to 0.4 parts by weight of non-LCST compounds, whereby the non-LCST compounds are

selected from the group consisting of ionic or non-ionic surfactants, emulsifiers, and antiagglomerants, or

salts of (mono- or multivalent) metal ions, or

carboxylic acid salts of multivalent metal ions, or

stearates or palmitates of mono- or multivalent metal ions

IV) no or 0.005 to 0.3 parts by weight of antioxidants; and

V) 0.005 to 1.5 parts by weight of volatiles having a boiling point at standard pressure of 200° C. or less.

3. The composition according to claim 2 , wherein the components I) to V) add up to 100.00501 to 102.700000 parts by weight, and together represent 99.50 to 100.00 wt %, and the copolymer is a copolymer of at least one isoolefin monomer and at least one multiolefin monomer.

4. A copolymer composition comprising:

I) 96.0 wt. % or more of a copolymer, wherein the copolymer is a copolymer of at least one isoolefin monomer and at least one multiolefin monomer, and

II) 1 ppm to 5,000 ppm of at least on lower critical solution temperature (LCST) compound,

whereby the copolymer composition has an ash content, measured according to ASTM D5667, of 0.25 wt. % or less.