Abstract: A thermally expandable composition, including (a) at least one polymer P, cross-linkable by a free-radical initiator, and (b) at least one solid butyl rubber BRu, and (c) at least one free-radical initiator, and (d) at least one blowing agent, and (e) at least one tackifier TA, whereby the cured expanded composition has a volume increase compared to the uncured composition of less than 1300%. The thermally expandable composition is able to provide good expansion behaviour and good adhesion on metal surfaces and is especially suitable for baffle and/or reinforcement elements, e.g. in automotive manufacturing.

Abstract: A thermally expandable composition, including at least one polymer, cross-linkable by peroxide, at least one peroxide, preferably at least one antioxidant, at least one chemical blowing agent, and at least one activator, wherein the activator includes at least one compound selected from formula (I), wherein radicals R1 and R4 represent hydrogen atoms or monovalent alkyl radicals with 1 to 10 carbon atoms which optionally include oxygen atoms; R2 and R3 represent hydrogen atoms or monovalent alkyl radicals with 1 to 10 carbon atoms which optionally include oxygen atoms, nitrogen atoms, and/or aromatic moieties or R2 and R3 together form a divalent alkyl radical with 1 to 10 carbon atoms which optionally includes oxygen atoms, nitrogen atoms or aromatic moieties. The composition shows excellent properties in terms of expansion stability over a wide temperature range, can be expanded at temperatures below 150° C. and is suitable for baffle and/or reinforcement elements.

Abstract: A thermally expandable composition, including at least one polymer, cross-linkable by peroxide, at least one peroxide, preferably at least one antioxidant, at least one chemical blowing agent, and at least one activator, wherein the activator includes at least one compound selected from formula (I), wherein radicals R1 and R4 represent hydrogen atoms or monovalent alkyl radicals with 1 to 10 carbon atoms which optionally include oxygen atoms; R2 and R3 represent hydrogen atoms or monovalent alkyl radicals with 1 to 10 carbon atoms which optionally include oxygen atoms, nitrogen atoms, and/or aromatic moieties or R2 and R3 together form a divalent alkyl radical with 1 to 10 carbon atoms which optionally includes oxygen atoms, nitrogen atoms or aromatic moieties. The composition shows excellent properties in terms of expansion stability over a wide temperature range, can be expanded at temperatures below 150° C. and is suitable for baffle and/or reinforcement elements.