Novel Polymeric Antioxidants for Materials

Dhawan, Ashish; Kumar, Vijayendra; Parmar, Virinder S.; Cholli, Ashok L.

doi:10.1002/9781118445440.ch13

Cited by 9 publications

(11 citation statements)

References 67 publications

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“…The AO of a number of polymerized phenols as measured by the beta-carotene assay is summarized in Table 6 [83]. As seen in the table, all polymeric phenols reported an enhanced AO compared to their monomeric analogues.…”

Section: Antioxidant Activity Of Substituted Phenolsmentioning

confidence: 99%

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Antioxidant Activity of Synthetic Polymers of Phenolic Compounds

Nagarajan

Kumar

et al. 2020

Polymers

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In recent years, developing potent antioxidants has been a very active area of research. In this context, phenolic compounds have been evaluated for their antioxidant activity. However, the use of phenolic compounds has also been limited by poor antioxidant activity in several in vivo studies. Polymeric phenols have received much attention owing to their potent antioxidant properties and increased stability in aqueous systems. To be truly effective in biological applications, it is important that these polymers be synthesized using benign methods. In this context, enzyme catalyzed synthesis of polymeric phenols has been explored as an environmentally friendly and safer approach. This review summarizes work in enzymatic syntheses of polymers of phenols. Several assays have been developed to determine the antioxidant potency of these polymeric phenols. These assays are discussed in detail along with structure-property relationships. A deeper understanding of factors affecting antioxidant activity would provide an opportunity for the design of versatile, high performing polymers with enhanced antioxidant activity.

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Section: Antioxidant Activity Of Substituted Phenolsmentioning

confidence: 99%

“…The structures of these monomers are summarized in Figure 5. Dhawan et al [83] polymerized substituted phenols using hydrogen peroxide as the oxidant and peroxidases as catalysts. Among the hindered phenol compounds used as AO, 2-tert-butylhydroquinone (t-BHQ) is an indispensable AO in the food industry.…”

Section: Polymerization Of Substituted Phenolsmentioning

confidence: 99%

Antioxidant Activity of Synthetic Polymers of Phenolic Compounds

Nagarajan

Kumar

et al. 2020

Polymers

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“…84,[134][135][136][137][138][139][140] Several commercially avail-able monomeric mono-, di-and trihydric phenolic antioxidant compounds (some of which have commercial applications), after suitable modification using lipasecatalysed reactions, were polymerized with horse radish peroxidase (HRP) or a cheaper chemical reagent to generate a new class of polymeric antioxidants that have superior properties compared with the starting monomeric compounds (Scheme 28). [135][136][137][138][139][140][141] These phenolic polymers showed a superior antioxidant performance and exceedingly remarkable applications in preserving petroleum products, cosmetics, cooking and edible oils, lubricants, polymeric materials, automobile oils, gasoline, meat and dairy products, etc. in increasing their shelf life and performance.…”

Section: -133mentioning

confidence: 99%

“…In this eff ort, we have successfully documented that these novel polymeric antioxidants off er superior antioxidant activities with significantly improved thermal stability. [135][136][137][138][139][140][141] These polymers have been synthesized via an environmentally benign chemoenzymatic methodology using two enzymes, viz. a lipase (Novozym 435) and an oxidase (HRP) (Scheme 28).…”

Section: -133mentioning

confidence: 99%

Synthesis of macromolecular systems via lipase catalyzed biocatalytic reactions: applications and future perspectives

et al. 2016

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“…It is difficult to achieve a homogeneous mixture and maintain a minimum effective antioxidant concentration throughout the PP matrix. 8 As a result, the concentrated antioxidants near the polymer surfaces also accelerate the loss of antioxidant when exposed to solvents, heat, or strong electric fields. 9 The research on polymeric antioxidants has recently gained some attention with the objective of addressing common additive loss issues.…”

Section: ■ Introductionmentioning

confidence: 99%

Polypropylene Copolymer Containing Cross-Linkable Antioxidant Moieties with Long-Term Stability under Elevated Temperature Conditions

et al. 2017

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Despite its commercial success, isotactic polypropylene (PP) is not suitable for the applications that require long-term exposure to high-energy conditions, such as elevated temperatures, UV radiation, or high electric fields, due to the combination of polymer chain oxidative degradation, incompatibility with polar additives (antioxidants, stabilizers, etc.), and low material softening temperature. This paper presents a new solution that can simultaneously address both chemical and physical limitations. The idea is to develop a new PP-HP copolymer that contains some specific hindered phenol (HP) groups, homogeneously distributed along the polymer chain. These PP-bound HP pendant groups can not only effectively protect PP chains from the oxidative degradation but also engage in a facile cross-linking reaction to form a 3-D network structure during the oxidation reaction. One accelerated oxidation test in air at 190–210 °C shows this distinctive advantage. While a commercial PP polymer (containing common antioxidants and stabilizers) degrades within 1 h, a PP-HP copolymer with about 1 mol % (9 wt %) HP groups shows almost no detectable weight loss after 1000 min. In an ASTM endurance test under a targeted application temperature (140 °C in air), the commercial PP shows 1% weight loss within about 10 days. On the other hand, this new PP-HP lasts for 105 days (4 order increase) under the same condition. In the strain–stress curve measurement, the PP-HP film also shows no detectable change in tensile strength and modulus after constant heating the polymer film at 140 °C in air for 1 week. Overall, the experiment results present the potential of expanding PP applications into a much higher temperature range (>140 °C) under oxygen oxidative environments.

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Novel Polymeric Antioxidants for Materials

Cited by 9 publications

References 67 publications

Antioxidant Activity of Synthetic Polymers of Phenolic Compounds

Antioxidant Activity of Synthetic Polymers of Phenolic Compounds

Synthesis of macromolecular systems via lipase catalyzed biocatalytic reactions: applications and future perspectives

Polypropylene Copolymer Containing Cross-Linkable Antioxidant Moieties with Long-Term Stability under Elevated Temperature Conditions

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