Thbayh Dalal K, Reizer Edina, Kahaly Mousumi U, Viskolcz Béla, Fiser Béla
Institute of Chemistry, University of Miskolc, 3515 Miskolc, Hungary.
Polymer Research Center, University of Basrah, 61004 Basrah, Iraq.
Polymers (Basel). 2022 Aug 27;14(17):3518. doi: 10.3390/polym14173518.
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.
各种各样的添加剂被用于改善最终聚合物产品的特定特性。抗氧化添加剂（AAs）可以防止氧化应激，从而防止聚合物材料的损坏。在这项工作中，通过使用计算工具探索了Santowhite（SW）作为合成抗氧化剂和抗坏血酸（Asc）作为天然抗氧化剂的抗氧化潜力及其适用性。两种密度泛函理论（DFT）方法，M05-2X和M06-2X，已与气相中的6-311++G(2d,2p)基组结合应用。考虑了三种抗氧化机制：氢原子转移（HAT）、单电子转移-质子转移（SET-PT）和顺序质子损失电子转移（SPLET）。已针对每个潜在的氢供体位点计算了键解离焓（BDE）、电离势（IP）、质子解离焓（PDE）、质子亲和力（PA）和电子转移焓（ETE）。结果表明，Asc的抗氧化潜力高于SW。此外，一些C-H键，取决于它们在结构中的位置，是有效的自由基清除剂，但O-H基团更容易向自由基提供H原子。尽管如此，这两种添加剂都有可能用于保护常见聚合物并防止氧化应激引起的材料劣化。
