Influence of Structure of Chemically Grafted onto Polyethylene Surface Two-Component Titanium-Phosphoroxide Nanostructures on the Properties of Composite Material

Nanostructures with different mutual arrangement of phosphorus and titanium oxide groups were synthesized on the surface of low-density polyethylene (LDPE) films using the molecular layering technology by treatment in a different predetermined sequence with TiCl4, POCl3 and H2O vapors. Based on the data of atomic force microscopy, differential thermal analysis, as well as the assessment of the energy characteristics of the surface by the value of the contact angle, it is shown that the sequence of formation of elemental oxide structures has a significant effect both on the chemical composition of surface nanostructures and on the surface morphology and thermal oxidation resistance of polyethylene. Depending on the sequence of introduction of additives, their concentration and ratio in grafted nanostructures change, surface energy increases by 30–50%, and the amounts of polar and dispersion components in its composition largely depend on the moisture content of the environment. It has been found that chemical modification with elemental oxide groups results in a smoothing of the matrix surface, and local destruction of the polymer is observed during the synthesis of two-component nanostructures. The presence of modifiers leads to an increase in the thermal-oxidative resistance of the composition by 50–110°, depending on its structure and composition, in comparison with the original LDPE. Therewith titanium is the most active inhibitor of polymer oxidation.