Abstract: In a system for feeding fluid into an exhaust gas after-treatment system, during operation fluid is fed via a feed line of the dispensing unit from a main container and is partially returned via a return line to the main container. A diaphragm pressure container is provided on the feed line downstream of a pump and a non-return valve toward the dispensing unit. During operation of the pump, the diaphragm pressure container is filled with fluid. The diaphragm pressure container is emptied as soon as the pump stops operating. In this way, the dispensing unit is cooled even after the operation of the system has ended, thereby protecting electronic components of the same from overheating.

Abstract: The present invention concerns a polycyanurate foam with a structural element A and either terminal amino groups and/or at least one of the following structural elements B, C, or D: wherein the foam has closed pores that contain carbon dioxide. This foam can be produced in that a substance is worked into the starting material for the polycyanurate that releases water or alcohol approximately at the start of polymerization either spontaneously or thermally or catalytically induced. The water/alcohol reacts with free cyanate groups under cleavage of CO2. The resulting amino groups can react further in the polymerization.

Abstract: In a system for feeding fluid into an exhaust gas after-treatment system, during operation fluid is fed via a feed line of the dispensing unit from a main container and is partially returned via a return line to the main container. A diaphragm pressure container is provided on the feed line downstream of a pump and a non-return valve toward the dispensing unit. During operation of the pump, the diaphragm pressure container is filled with fluid. The diaphragm pressure container is emptied as soon as the pump stops operating. In this way, the dispensing unit is cooled even after the operation of the system has ended, thereby protecting electronic components of the same from overheating.

Abstract: The present invention concerns a polycyanurate foam with a structural element A and either terminal amino groups and/or at least one of the following structural elements B, C, or D: wherein the foam has closed pores that contain carbon dioxide. This foam can be produced in that a substance is worked into the starting material for the polycyanurate that releases water or alcohol approximately at the start of polymerization either spontaneously or thermally or catalytically induced. The water/alcohol reacts with free cyanate groups under cleavage of CO2. The resulting amino groups can react further in the polymerization.