Figure 7 Mass distribution of polybutadiene considering four catalytic sites.
Comparing Figure 7 with the others, it is observed that the distribution of molar masses is significantly wider than the others, that is, the polydispersity index presented by the simulation with four active sites is the highest among the simulations and the closest to found in the literature (MÉNDEZ-HERNÁNDEZ, 2016; VASCONCELOS, 2019). The distribution still presents bimodality and the average molar masses are even greater following the trend that the more active centers, the greater the average molar masses.
It can be seen that all curves have a Gaussian model. The curves that correspond to each site individually show unimodality. As a further catalytic site is increased, bimodality is inserted in the polymer distribution curve. It can be seen that in case 1, we have only one unimodal Gaussian curve, whereas for all other cases this bimodality is generated.
All the average molar masses and polydispersity index for all the four simulations are presented in Table 5.
Table 5 Results of \(\mathbf{M}_{\mathbf{n}}\),\(\mathbf{M}_{\mathbf{w}}\) and PDI generated in all cases.