An additive elastomeric manufactured part is comprised of extrudates comprised of a reaction product of a multifunctional Michael donor and multifunctional Michael acceptor and a rheological modifier. The additive elastomeric manufactured part may have a high elongation and resistance to heat. Said part may be made by dispensing a mixture of the multifunctional Michael donor, multifunctional Michael acceptor, rheological modifier and a catalyst through a through a nozzle to form an extrudate deposited on a base. The base, nozzle or combination thereof is moved while dispensing the mixture so that there is horizontal displacement between the base and nozzle in a predetermined pattern to form an initial layer of the material on the base. Subsequent layers are then formed on the initial layer by repeating the dispensing and movement on top of the initial layer and layers that follow.