| abstract |
A product, especially a master-batch for producing thermally expandable compositions, is obtainable or obtained by reacting, preferably by extruding, a mixture comprising: (a) at least one polymer P, cross-linkable by peroxide, and (b) at least one coagent, especially an acrylate A, and (c) at least one peroxide PE, wherein the mixture is reacted such that the product has an average melt flow index (MFI) of between 0.1 and 8 g/10 min, preferably between 0.2 and 5 g/10 min, more preferably between 0.25 and 1.25 g/10 min. |