Polymer composition for wire and cable applications with advantageous thermomechanical behaviour and electrical properties

An insulation layer comprising a polymer composition, the polymer composition comprising a blend of:

• a) a low density polyethylene (LDPE);
• and
• b) a conjugated aromatic polymer;
• wherein the LDPE is present in an amount of 90 to 99.99 wt % relative to the total weight of the polymer composition as a whole;
• wherein the conjugated aromatic polymer b) is present in an amount of from 0.01 to 10 wt %, relative to the total weight of the polymer composition as a whole;
• wherein the insulation layer does not comprise a carbon black,
• wherein the polymer composition is prepared by melt-mixing above the melting point of at least the LPDE and the melt-mixed polymer composition is heat treated by remelting at a temperature above the melting temperature of the conjugated aromatic polymer of from 220° C. to 350° C.,
• wherein the conductivity of the polymer composition is 1.0 E-12 S/cm or less when measured according to DC conductivity method as described under “Determination Methods”,
• wherein DC conductivity when measured according to DC conductivity method as described under “Determination Methods” of the polymer composition is at least 10% lower than an otherwise identical polymer composition not comprising the conjugated aromatic polymer, and
• wherein the conjugated aromatic polymer is a polythiophene having the general formula (I):
• wherein R1 is hydrogen and R2 is hexyl;
• and
• wherein n is an integer in the range 2 to 1000.