Evonik Roehm Gmbh

Evonik Degussa Gmbh

Evonik Rohm Gmbh

Karlsruher Institut Fur Technologie

Christopher Barner-Kowollik

Friedrich Georg Schmidt

Stefan Hilf

Jiawen Zhou

Andre Hennig

Kim Klaus Oehlenschlaeger

Nathalie Guimard

Simon Krause

Andrew John Inglis

Leena Nebhani

Emmanouil Spyrou

André Hennig

Jan Mueller

Ozcan Altintas

ÖZcan Altintas

Oezcan Altintas

Kim Klaus ÖHLENSCHLÄGER

The invention relates to low molecular mass products and to the use thereof as reversible or permanent low-temperature crosslinkers in Diels-Alder reactions.

Low molecular weight products and use thereof as reversible or permanent low-temperature crosslinking agent in Diels-Alder reactions

A method for the reversible crosslinking of, for example, adhesives or coating materials, and a composition stable on storage at room temperature for implementing the crosslinking reaction. The reversible crosslinking method allows very rapid crosslinking even at a low first temperature, and undoing of the crosslinks at higher temperatures, thereby recovering thermoplastic processability and, for example, allowing the originally bonded substrates to be parted from one another again easily. A particular aspect is that a plurality of cycles of crosslinking and undoing of the crosslinks are possible with the present system. A feature of the system used for the reversible crosslinking is that it contains two components, A and B, where component A is a compound having at least two protected dithioester functionalities, preferably cyanodithioester functionalities, and component B is a compound having at least two diene functionalities.

Functional materials with reversible crosslinking

The present invention relates to an innovative method for controlling the viscosity of, for example, adhesives or coating formulations. The method for controlling viscosity allows very rapid thermoplastic curing of a formulation even at room temperature and a significant reduction in the viscosity at higher temperatures, thereby regaining the capacity for simple processing and allowing, for example, the originally bonded substrates to be separated from one another again with ease. A particular aspect in this context is that a plurality of cycles of thermoplastic curing and a significant reduction in the viscosity are possible with the present system.

Functional materials with controllable viscosity

The present invention relates to innovative materials which are reversibly crosslinkable by means of a thermoreversible mechanism and/or whose viscosity is reversibly adjustable. Through the use of bishydrazones or conjugated bis-Schiff bases as diene components in aza-Diels-Alder reactions, functional materials are generated that feature controllable viscosity and/or reversible crosslinking.

Functional materials having a controllable viscosity or reversible crosslinking via aza Diels-Alder reactions with bishydrazones or conjugated bis-Schiff bases

The invention relates to the use of a powder made of a polymer, which of two or more components with functionalities suitable for Diels-Alder reactions, or of a powder mixture (dry blend) made of powders respectively of at least one of the reactive components, where these together enter into the Diels-Alder reaction with one another and are capable of a retro-Diels-Alder reaction, in a rapid-prototyping process. The invention further relates to moldings produced with use of said polymer powder through a layer-by-layer shaping process in which regions of a powder layer are melted selectively. The molding here can be removed from the powder bed after cooling and hardening of the regions previously melted layer-by-layer.

Polymer powder for producing three-dimensional objects

The present invention relates to innovative materials which can be crosslinked by means of two different crosslinking mechanisms, the first crosslinking mechanism being an irreversible crosslinking. The second crosslinking mechanism is a thermoreversible mechanism. As a result of this thermoreversible change in the arc length, properties of the crosslinked material can be decisively changed and controlled, including flexibility, elasticity and other mechanical properties, but also chemical properties, the gas permeability and vapor permeability and storage capacity of the network. In this way it would be possible, for example, to store energy sources such as fuels.

Materials having a controllable degree of crosslinking

The present invention relates to an innovative method for the reversible crosslinking of, for example, adhesives or coating materials. The reversible crosslinking method allows very rapid crosslinking even at room temperature and undoing of the crosslinks at higher temperatures, thereby regaining the capacity for thermoplastic processing and allowing the originally bonded substrates to be separated from one another again with ease. A particular aspect in this context is that a plurality of cycles of crosslinking and undoing of the crosslinks are possible with the present system.

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Stutensee, Germany

Christopher Barner-Kowollik