washing the vents the bottom stream 8 from the column c1 is mainly composed of desired 2 propylheptyl acrylate with the catalyst the polymerization inhibitors and the heavy byproducts and can comprise residual traces of light compounds unreacted reactants this stream 8 is sent to a film evaporator e in order to separate the catalyst from the finished product the separation of the catalyst in the u201c stripped u201d mixture not requiring the use of a distillation column the purified 2 propylheptyl acrylate 9 is separated at the top and a fraction 10 comprising the catalyst the polymerization inhibitors and also the heavy reaction byproducts is separated at the bottom a part 11 of this stream 10 can optionally be recycled in the reaction in the reactor a the remainder being discarded and incinerated in order to prevent an excessively great accumulation of heavy byproducts in the reactor use may in particular be made as film evaporator of a falling film evaporator or a wiped film evaporator this type of evaporator gives the advantage of having a reduced residence time which limits the formation of additional heavy compounds downstream of the reaction section this evaporator is essentially composed of a cylindrical part heated by a jacket of an upper part used for the separation of the vapors and of a rotor rotating at high speed the stream to be treated is spread over the entire heating surface in the form of a highly turbulent film the vapors which are.