No abstract

A wide variety of additives are used to improve specific characteristics of the final polymeric product. Antioxidant additives (AAs) can prevent oxidative stress and thus the damage of polymeric materials. In this work, the antioxidant potential and thus the applicability of Santowhite (SW) as synthetic and ascorbic acid (Asc) as natural AAs were explored by using computational tools. Two density functional theory (DFT) methods, M05-2X and M06-2X, have been applied in combination with the 6-311++G(2d,2p) basis set in gas phase. Three antioxidant mechanisms have been considered: hydrogen atom transfer (HAT), single electron transfer-proton transfer (SET-PT), and sequential proton loss electron transfer (SPLET). Bond dissociation enthalpy (BDE), ionization potential (IP), proton dissociation enthalpy (PDE), proton affinity (PA), and electron transfer enthalpy (ETE) have been computed for each potential hydrogen donor site. The results indicate that the antioxidant potential of Asc is higher than SW. Furthermore, some of the C-H bonds, depending on their position in the structures, are potent radical scavengers, but O-H groups are more prone to donate H-atoms to free radicals. Nonetheless, both additives can be potentially applied to safeguard common polymers and prohibit oxidative stress-induced material deterioration.

Inorganic-organic hybrid materials are of the materials of interest to researchers for the purpose of developing them in this work. A hybrid material consisting of conductive polymer polyaniline (PANI) doped with dodecyl benzene sulfonic acid (DBSA) C18H30O3S with titanium oxide nanoparticles (TiO2 NPs ) was prepared by the direct chemical polymerization method, and then the optical and surface properties of the prepared materials were studied by UV-VIS spectroscopy, Scanning electron microscopy SEM , and Energy Dispersive X-Ray EDX. The EDX results confirm the presence of TiO2 in the composite material .The results clearly demonstrate that the composite films have good optical properties. As the content of TiO2 was increased in the polymer matrix, the shift of the optical absorption was observed.