Utilization of Petroleum‐Based Asphaltenes for Tuning the Properties of Polybutadiene at Solid Interphases in Thin Films

ABSTRACT

Asphaltenes exhibit potential for various applications, such as polymer fillers. Moreover, poly(butadiene‐1,4) (PB) is among the unsaturated synthetic rubbers and one of the most industrially important raw materials. Moreover, polymers show deviations from their bulk behavior at solid interfaces when confined to surfaces, as in polymer thin films. The current report aims to cross‐link PB via a green approach under ultraviolet (UV) light and to tune its properties, such as wettability and dynamics, at solid interfaces, both in the pristine state and in blends with asphaltenes. First, cross‐linking of PB in thin films prepared by solution and non‐solvent casting at solid interfaces, either neat or with asphaltenes, is demonstrated by infrared and Raman spectroscopy, and changes in the chain dynamics of cross‐linked PB are studied by low‐field nuclear magnetic resonance (LF‐NMR) relaxometry. Water contact angle measurements indicate that the wettability of PB thin films changes from hydrophobic to hydrophilic upon asphaltene treatment by switching the preparation method from solution to non‐solvent casting, and that the PB/asphaltene thin films demonstrate the highest hydrophilic character, with a nearly 20%–23% decrease in contact angle. Using the ethanol/deionized water azeotrope as the non‐solvent in non‐solvent casting does not affect the results compared with methanol.