Durability study of asphaltene-reinforced HDPE and LDPE composites under UV irradiation and local weathering exposure

The durability of HDPE and LDPE composites was studied using asphaltene as filler. Asphaltene is the polar macromolecules present in the crude oils. Examining the FTIR spectra of the composites revealed the lack of chemical bonds between asphaltene and HDPE/LDPE in the composite. Filler, asphaltene, is being a part of the physical mixture that does not make any covalent link with HDPE and LDPE polymers. The changes in the durability of the composites were monitored in samples exposed to UV irradiation for 480 h as well as natural outdoor weathering over a period of 6, 12, and 18 months. Superior light shielding by asphaltene filler leads to the stabilization of the composites. Alternatively, chemical effects may have also played a vital role in enhancing the weatherability of composites. In all composites studied, the natural and artificial weatherability compared to non-exposed HDPE and LDPE enhanced maximum load, tensile strength, and yield stress significantly due to the presence of asphaltene as a filler; however, percent elongation and modulus of elasticity decreased. Therefore, efficient reinforcement afforded by asphaltene is not accompanied by significant loss or enhancement in the durability of the composite.