By using the Density Functional Theory (DFT), NBO charges and the “supermolecule”approach we have been able to determine the molecular interactions between low density linear polyethylene (LLDPE) and chitosan (Q), employing the chemical modification of PELBD with acrylamide (AAm) as a compatibilizing agent LLDPE-g-AAm). The obtained results indicate that in the molecules of the LLDPE/Ch blend are acting very weak intermolecular forces of Debye type, while among molecules of Q/ LLDPE-g-AAm blend may be forming a stable complex due to the presence of hydrogen bonds.