The study of the synthesis of new chemical compounds are today often associated with a study by the methods of quantum mechanics, which use the distribution of electrons distributed in orbitals around the molecule, imply often high computing times which limit their use to small molecules or require the use of many approximations. The theoretical study "quantum chemistry" which is devoted to the modeling of the synthesis of the amphiphilic block copolymer poly (N-vinylpyrrolidone) -b-poly (4-vinyl benzene chloride) is based on DFT. This theoretical calculation aims to complete the description of this copolymer to be able to define the structure-property correlation. Thus, we use three different bases B3LYP, 6-31G and 6-31G ** to minimize energy and choose the best base. We will also discuss the results of the NMR, 13C NMR spectra and the IR spectrum.