A recyclable crosslinked polymeric foam includes a reaction product of 0.1 to 10 parts by weight of a crosslinking agent and 0.1 to 5 parts by weight of a radical initiator, based on 100 parts by weight of a polymeric material. The crosslinking agent is represented by the following formula:

##STR00001##

wherein R is an alkylene group having 2 to 10 carbon atoms, an arylene group having 6 to 18 carbon atoms, or a cycloalkylene group having 6 to 18 carbon atoms.

This disclosure relates to a composite comprising (a) a rubber layer comprising a cured rubber and optionally a first copolymer having carboxyl groups or anhydride groups; and (b) a foam layer comprising a crosslinked ethylene vinyl acetate and optionally a second copolymer having carboxyl groups or glycidyl methacrylate groups; wherein the foam layer has at least one surface adhering to the rubber layer directly, and provided that either the first copolymer or the second copolymer is present, and the composite is free of glues or adhesive films in the interface between the rubber layer and the foam layer.

This invention relates to a foaming composition, comprising at least one ethylene-vinyl acetate (EVA) copolymer; at least one foaming agent; at least one peroxide compound; at least one polyamine; at least one crosslinking enhancer; at least one primary antioxidant; and at least one secondary antioxidant; the content of the crosslinking enhancer is from 0.1 to 3% by weight based on the total weight of the composition. A foaming article cured from the foaming composition under the temperature range of 80 to 120° C. according to the present invention exhibits high initial volume expansion ratio at the baking window from 130 to 200° C. and shows excellent stability after storage.

A thermally expandable preparation pumpable at application temperatures in the range of 50 to 120° C., is provided containing: at least one polymer selected from binary copolymers containing at least one monomer unit selected from vinyl acetate, (meth)acrylic acids, styrene and derivatives thereof, and terpolymers based on at least one first monomer selected from the monounsaturated or polyunsaturated hydrocarbons, and at least one second monomer selected from (meth)acrylic acids and derivatives thereof, and at least one third monomer selected from epoxy-functionalized (meth)acrylates, as well as combinations of the first two; at least one liquid polymer selected from liquid hydrocarbon resins, liquid polyolefins and liquid polymers based on one or more diene monomers; at least one peroxide; at least one thermally activatable blowing agent; and at least one adhesion promoter; as well as methods to stiffen/reinforce or seal structural components by application of the preparation.

The present application relates to a preparation that is pumpable, thermally curable and expandable at application temperatures, typically in the range of 30 to 120° C., and contains at least one solid rubber, at least one liquid rubber, at least one thermally activatable blowing agent and a curing agent system containing at least one peroxide and at least one quinone, quinone dioxime or dinitrosobenzene, to a method for stiffening structural components having thin-walled structures using such preparations or for sealing cavities in structural components using such preparations, and to the use of these preparations for stiffening such structures or for sealing cavities in structural components.

A thermally expandable composition comprising a thermoplastic polymer compound and/or an elastomer compound, at least one blowing agent including at least one dicarboxylic acid salt of an aminoguanidine compound, optionally at least one free radical initiator and/or a vulcanization system, and at least one guanidine derivative. The invention is also related to baffle and/or a reinforcement element for hollow structures including the thermally expandable composition, to a process for manufacturing the baffle and/or reinforcement element, to use of the baffle and/or reinforcement element for sealing, baffling, or reinforcing of a cavity or a hollow structure, and to a method for sealing, baffling and/or reinforcing a cavity or hollow structure.

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), ##STR00001##
wherein radicals R.sup.1 and R.sup.4 represent hydrogen atoms or monovalent alkyl radicals with 1 to 10 carbon atoms which optionally include oxygen atoms; R.sup.2 and R.sup.3 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 R.sup.2 and R.sup.3 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.

An object of the present invention is to provide a gas generating agent having an appropriate initial decomposition temperature, generating a large amount of gas, and generating only a small amount of ammonia gas. The object can be accomplished by a gas generating agent containing a guanidine derivative represented by the following formula (1).

##STR00001##

A process for producing a polymeric article is provided that includes: sequentially filling a female mould (11) with a first, second, and third batches, wherein the first and third batches include first and third polymeric materials (1p, 3p), and the second batch includes a second polymeric material (2p) and a blowing agent (2b), closing the thus filled cavity with a lid (12) to form a mould defining a closed cavity (10c) of constant volume in time, heating the mould (10) to a processing temperature, to melt the first, second, and third polymeric materials (1p-3p) and to expand the second polymer agent by activation of the blowing agent, cooling and removing the lid (12) to open the cavity and extracting the polymeric article. At least the second polymeric material (2p) includes at least 50 wt. % of recycled polymer in the form of shredded flakes.

A foam composition comprises a recycled polyvinyl butyral in an amount from 5 wt % to 70 wt %; an ethylene-ester copolymer in an amount from 10 wt % to 70 wt %; a foaming agent in an amount from 0.5 wt % to 3.5 wt %; a peroxide crosslinking agent in an amount from 0.5 wt % to 3.0 wt %; and a hydrazide crosslinking agent in an amount from 0.1 wt % to 2.5 wt %, based on a total weight of the foam composition. A foam produced from the foam composition can avoid emitting an unpleasant odor of aldehydes, and the foam also has good mechanical properties and good resilience.