Effect Of Phenolic Antioxidants Research Articles

Green process to produce phytonutrients from crude palm oil: Effects of phenolic antioxidants on tocols and carotene retention during enzymatic hydrolysis

The enzymatic hydrolysis of crude palm oil (CPO), followed by separation, has been studied as an alcohol-free alternative to concentrate and extract palm carotene and tocols. However, a considerable amount of palm phytonutrients may be lost during hydrolysis due to the production of free fatty acids (FFAs), which promote auto-oxidation. In this research, the effects of incorporating phenolic antioxidants, including butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and tertiary butyl hydroquinone (TBHQ), on the enzymatic hydrolysis of CPO and the retention of phytonutrients were evaluated. The addition of phenolic antioxidants did not affect the production of FFAs. Meanwhile, its addition positively impacted the phytonutrients preservation as the retentions of carotene and tocols were increased up to over 90 %; a great improvement compared to the 58 % carotene and 23 % tocols retentions without phenolic antioxidants. The results indicated that TBHQ is the best-performing phenolic antioxidant, owing to its low steric hindrance and higher solubility in the water phase. The inclusion of 0.08 wt% TBHQ in the reaction improved the carotenes and tocols retentions to 88 % and 98 %, respectively, after 24 h of hydrolysis. In conclusion, adding phenolic antioxidants considerably enhances the preservation of palm carotene and tocols during enzymatic hydrolysis. The results of this study revealed that the phenolic antioxidants performed in the following order: TBHQ > BHT > BHA.

Molecular Networking-Guided Isolation of a Phenolic Constituent from Prunus mume Seed and Its Antioxidant and Anti-Inflammatory Activities.

Prunus mume (Maesil) is used in health foods and alternative medicine in Korea. In the present study, the anti-inflammatory and antioxidant effects of phenolics from P. mume seed extracts were examined. First, the biological activities of various P. mume extracts were evaluated, and the profiles of their chemical compounds were investigated by Global Natural Products Social (GNPS)-molecular networking. Among these extracts, fermented Maesil seed extract (FMSE) showed potent anti-inflammatory and antioxidant activity, and demonstrated the presence of phenolic clusters in GNPS-based studies. Thus, the chemical constituents of this extract were further investigated. Subsequently, the chemical composition of the active CH2Cl2 fraction of FMSE was explored using an advanced GNPS analysis tool, MolNetEnhancer. In addition, the molecular structure of compound 1 from the CH2Cl2 fraction was similarly predicted with Network Annotation Propagation (NAP). Finally, the anti-inflammatory and antioxidant effects of compound 1 were confirmed by lipopolysaccharide (LPS)-induced nitric oxide production and DPPH assay. Western blot analysis revealed that compound 1 downregulated the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins. The molecular docking simulation additionally confirmed significant interactions of 1 with iNOS and COX-2 proteins. Our findings suggested that an integrated GNPS-based approach could prioritize samples in the early fractionation process and improve the accuracy of target compound prediction.

Effect of phenolic antioxidants on the thermal oxidation stability of high-energy–density fuel

The addition of antioxidants is normally adopted to improve the thermal oxidation stability of jet fuel, but the detailed antioxidation mechanism is still ambiguous. Herein, the inhibition of exo-tetrahydrodicyclopentadiene (the main component of JP-10) toward thermal oxidation and deposition by phenolic antioxidants (2,6-di-tert-butyl-4-methyphenol (BHT), 6-tert-butyl-2,4-dimethyphenol (TBDP), 2,6-di-tert-butylphenol (DTBP), 2-tert-butyl-4-methoxyphenol (BHA) and 2-tert-butyl-4-methylphenol (TBMP)) was investigated to reveal antioxidation mechanism and screen the best antioxidant for high-energy–density fuel. The theoretical and experimental results show that the addition of all phenolic antioxidants can significantly inhibit fuel oxidation and prolong the shelf life. Importantly, TBDP and TBMP show better performance than other antioxidants since they can scavenge more radicals per antioxidant molecule. However, antioxidants form dimer products via the addition between phenoxyl radicals and alkyl radicals during short-term thermal stress, which has a higher tendency to produce deposits. Consequently, the addition of phenolic antioxidants causes more severe deposition when jet fuel serves as the coolant in aircrafts. This work would guide the rational design of antioxidant for practical application in high-energy–density fuel.

The Effect of Phenolic Antioxidants on the Nominal Tensile Strength of Nitrile Butadiene Rubbers during Full-Scale Exposure

The effect of phenolic antioxidants on the nominal tensile strength of nitrile butadiene rubbers has been studied. Rubber samples were exposed for 2 years on an open atmospheric site in the climatic conditions of Yakutsk, as well as in hydrocarbon environments. For products operating in air, it is recommended to use the antioxidants CO-3 and CO-4, and, for those operating in an oil medium, CO-4 and Stafen. For those in a medium of I-50A industrial oil, the modifier CO-3 is most suitable for use.

A Review on Harmful Effects of Phenolic Antioxidants– Zebrafish as a Potential Model to Evaluate Toxicity

A Review on Harmful Effects of Phenolic Antioxidants– Zebrafish as a Potential Model to Evaluate Toxicity

Determination of Cobalt(II)-Hydrogen Peroxide-Induced DNA Oxidative Damage and Preventive Antioxidant Activity by CUPRAC Colorimetry

The classical Fenton system composed of Fe(II) and H2O2 uses harsh oxidative conditions and cannot realistically simulate physiological oxidations which are less severe. Here, reactive oxygen species (ROS) were generated with a combination of CoSO4 and H2O2 to provide milder conditions. DNA was used as a biologically meaningful probe for monitoring the oxidative conversion. Oxidative hazard on DNA was accomplished in ammonia/ammonium chloride buffer at 37 °C, and the Fenton reaction was stopped with trichloroacetic acid (TCA). A suitable aliquot of this solution was added to cupric ion reducing antioxidant capacity (CUPRAC) reaction mixture, and the absorbance at 450 nm was recorded. The oxidized species derived from DNA were CUPRAC-reactive while intact DNA was not. The protective effects of antioxidants (AOxs), known to have radical scavenging effects, were tested; green tea and a synthetic fetal bovine serum (FBS) were also successfully used as real ROS scavengers. Although the classical iron-based Fenton procedure applied in ethanol medium generated CUPRAC-responsive products, the proposed system was perfectly ethanol-tolerant, enabling the CUPRAC measurement of DNA oxidation products against an unaffected reagent blank. The protective effects of phenolic antioxidants, perfectly solubilized in ethanol, could also be measured.

Effects of phenolic antioxidants on biodiesel oxidative stability and emission

Biodiesel is a high‐quality diesel alternative fuel, but it can get easily oxidized on long‐term storage. The addition of antioxidants can effectively improve the oxidation stability of biodiesel. In this study, the mechanism of phenolic antioxidants to inhibit the oxidation of biodiesel and reduce the NOX emission is discussed based on the experimental investigation. Antioxidants (0.8 wt%) 3‐tert‐butyl‐4‐methoxyphenol (BHA), rosemary (K1), and tea polyphenols (K2) were added to biodiesel B100. The antioxidant test was carried out at atmospheric temperature for 4320 h, and the peroxide value, acid values were measured. Then, 0.8 wt% of K1, K2, and BHA were added to B20, named as K1B20, K2B20, and BHAB20. The 186F diesel engine bench test was carried out under 10%, 25%, 50%, 75%, and 100% load at 3000 rpm, with HC, CO, NOX, and smoke emissions of various types of fuel (B20, BHAB20, K1B20, and K2B20) were measured. The results of antioxidant test showed that the antioxidant effect of rosemary was best, displaying a decrease in acid and peroxide values by 25% and 48%, respectively. The diesel engine bench test results showed that antioxidants had little effect on HC, CO, and smoke emission; however, the antioxidants significantly reduced NOX emission. The effect of natural antioxidant rosemary to reduce NOX emission is the best one. At 3000 rpm and 75% load, the NOx of B20 reduced by 9.4%. Among the three antioxidants, the experimental results verified the mechanistic analysis and provided the basis for the selection of antioxidants for biodiesel. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13146, 2019

Influence of grape seeds powder on preservation of fats in confectionary glaze

The polyphenol composition of grape seeds powder (GSP) and defatted grape seeds flour (DGSF) in water­alcohol (ethanol, isopropanol) extracts was studied by the chromatographic method. There was established the content of antioxidants, which are present in the form of phenolic acids (gallic, ellagic), stilbenes (resveratrol) and flavonoids, first of all, flavanols (catechin, epicatechin) and flavonols (kaemferol, myricetin, quercetin and its derivative glycosides). It was shown that the total content of polyphenols reaches a maximum size of about 4.5 % in gallic equivalent of the powder weight at the extraction of water­ethanol mixture with ethanol content of 50 % (w/w). The effect of phenolic antioxidants on peroxide (PV) and acid (AV) values of confectionery fats of lauric and non­lauric types in the model systems was studied as the markers of the rancidity formation process. It was proved that thanks to a high content of antioxidants in grape powders, the introduction of these powders in the composition of samples significantly slows down the process of auto­oxidation of fats. It was shown that grape powders as vegetable raw material are more stable in terms of catalyzing the process of fats hydrolysis in confectionery glaze. This is evidenced by the data on the activity of lipase enzyme, the magnitude of which is lower in the samples of grape seeds powders – 1.03 and 1.12 nm 3 /g for GSP and DGSF, respectively, compared with that of different samples of cocoa powder – 0.84 and 1.87 nm 3 /g. The study into changes in acid value of the samples also showed that the addition of GSP and DGSF as the source of antioxidants significantly inhibits the process of hydrolysis of fats to free fatty acids. The obtained results have a practical significance for the improvement of the process of confectionary glaze production in the direction of partial substitution of cocoa powder with grape seeds powders. This contributes to the creation of a product with a high nutritional value and which is more resistant to damage as a result of the process of oxidation and hydrolysis of fats

Superoxide Formation in Cardiac Mitochondria and Effect of Phenolic Antioxidants.

Since mitochondria are the main cellular source of reactive oxygen species, it is important to study the effect of dietary phenolic compounds on the level of ROS in these organelles. Using the EPR spectroscopy and TIRON probe, the ability of the investigated phenols (quercetin, rutin, caffeic acid, curcumin, and resveratrol) to scavenge superoxide anion radicals generated by isolated heart mitochondria of Wistar rats under variable oxygen partial pressure was studied. It was shown that during a 10 min incubation, caffeic acid in concentrations of 10-500 μM most effectively scavenged superoxide radicals formed in the complex III of the mitochondrial respiratory chain. A comparable antioxidant effect of rutin under these experimental conditions was observed at higher concentrations of 1-10 mM. The antioxidant activity of quercetin in the concentration range of 10-500 μM during the first minutes of incubation was higher than that of caffeic acid. Of the phenolic compounds studied, curcumin had the least effect on the superoxide radicals.

Two phenolic antioxidants in Suoyang enhance viability of \u2022OH-damaged mesenchymal stem cells: comparison and mechanistic chemistry

BackgroundSuoyang originates from a psammophyte named Cynomorium songaricum Rupr and has been known as a phenolic-antioxidant-enriched traditional Chinese herbal medicine. The present study attempted to investigate the protective effect of phenolic antioxidants in Suoyang towards •OH-mediated MSCs and then further discusses the chemical mechanisms.MethodsThe lyophilized aqueous extract of Suoyang (LAS) was prepared and characterized using HPLC. Then, two phenolic antioxidant references, epicatechin and luteolin-7-O-β-D-glucoside, along with LAS, were investigated for their effects on the viability of •OH-treated MSCs using the 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl (MTT) assay. The comparison and mechanistic chemistry of epicatechin and luteolin-7-O-β-D-glucoside were further explored using various antioxidant assays, including PTIO•-scavenging, FRAP (ferric ion reducing antioxidant power), ABTS+•-scavenging, and DPPH•-scavenging. Their Fe2+-binding capacities were also compared using ultraviolet (UV) spectra.ResultsThe HPLC analysis indicated that there are 8 phenolic antioxidants in LAS, including epicatechin, luteolin-7-O-β-D-glucoside, gallic acid, protocatechuic acid, catechin, isoquercitrin, phlorizin, and naringenin. The MTT assay revealed that epicatechin could more effectively increase the survival of •OH-treated MSCs than luteolin-7-O-β-D-glucoside. Similarly, epicatechin exhibited higher antioxidant abilities than luteolin-7-O-β-D-glucoside in the DPPH•-scavenging, ABTS+•-scavenging, FRAP, and PTIO•-scavenging assays. In the Fe2+-binding assay, luteolin-7-O-β-D-glucoside gave a stronger UV peak at 600 nm, with ε = 2.62 × 106 M−1 cm−1, while epicatechin produced two peaks at 450 nm (ε = 8.47 × 105 M−1 cm−1) and 750 nm (ε = 9.68 × 105 M−1 cm−1).ConclusionAs two reference antioxidants in Suoyang, epicatechin and luteolin-7-O-β-D-glucoside can enhance the viability of •OH-damaged MSCs. Such a beneficial effect may be from their antioxidant effects, including direct-antioxidant and indirect-antioxidant (i.e., Fe2+-binding) processes. In the direct-antioxidant process, proton (H+), one electron (e), or even hydrogen-atom (•H) transfer may occur to fulfill radical-scavenging (especially •OH-scavenging); in this aspect, epicatechin is superior to luteolin-7-O-β-D-glucoside due to the presence of more phenolic –OHs. The additional –OHs can also be responsible for the better cytoprotective effect. In terms of indirect-antioxidant potential, however, epicatechin is inferior to luteolin-7-O-β-D-glucoside due to the absence of a hydroxyl-keto moiety. These findings will provide new information about medicinal psammophytes for MSC transplantation.

Phenolic antioxidant 2,6-di-tert-butyl-p-cresol (vitamin E synthetic analogue) does not inhibit 1,1’-dimetyl-4,4’-bipyridium dichloride (paraquat)-induced structural chromosomal damage in cultured leukocytes of the dark-spotted-frog Pelophylax (Rana) nigr

Pro-oxidative effect of phenolic antioxidant (vitamin E) in combination with the initiators on human low-density lipoprotein is known. Recently I reported that oxidative stress induced by vitamin E in combination with the herbicide paraquat enhances structural chromosomal damage in cultured anuran leukocytes. In the present study, the phenolic antioxidant vitamin E-synthetic-analogue 2,6-di-tert-butyl-p-cresol (BHT) in combination with paraquat was found to enhance structural chromosomal damage in cultured Pelophylax (Rana) nigromaculatus leukocytes more than paraquat only and paraquat plus nicotinamido adenine dinucleotido phosphate served as positive control, although BHT only had no effect on induction of structural chromosomal damage. Paraquat plus BHT-enhanced structural chromosomal damage was inhibited by combination of the superoxide dismutase mimic Mn(III)tetrakis(1-methyl-4-pyridyl)porphyrin and the hydrogen peroxide scavenger catalase. In test based on reduction of paraquat cation, BHT was found to reduce paraquat cation chemically to paraquat monocation radical. These results suggest that BHT functions in chemically donating electron to paraquat and thereby induces an acute accumulation of reactive oxygen species, resulting in increase in chromosomal damage.

Effect of phenolic antioxidants on the dispersion state and chemical stability of olive oil O/W emulsions

The effect of gallic acid, catechin and quercetin on physical and chemical stability of olive oil-in-water emulsions was investigated. These molecules, characterised by different polarity and antioxidant activity, showed different interface activity and efficiency in delaying lipid oxidation. Gallic acid contributed positively to stabilise the colloidal properties of the systems toward physical instability whilst showed a low activity towards secondary oxidation. Catechin showed an interfacial localisation which was reflected in the enhancement of primary oxidation and in the inhibition of secondary oxidation. Quercetin poorly partitioned in the aqueous phase and was proven not to slow down the bimolecular phase of auto-oxidation. Results confirmed that polarity is not the only parameter to determine efficiency of antioxidants in emulsions but other variables, such as its antioxidant activity in terms of capacity and rapidity in donating an hydrogen atom, can affect its protective role towards lipids auto-oxidation in emulsions.

Activation of rat liver microsomal glutathione S-transferase by gallic acid

The effect of phenolic antioxidants on the rat liver microsomal glutathione S-transferase (MGST1) was investigated in vitro. When microsomes were incubated with various polyphenolic antioxidants, gallic acid (3,4,5-trihydroxybenzoic acid) markedly increased MGST1 activity and the increase was prevented in the presence of superoxide dismutase (SOD) or catalase. The MGST1 activity increased by gallic acid was decreased by further incubation with sodium arsenite, a sulfenic acid reducing agent, but was not with dithiothreitol, a disulfide bond reducing agent. The incubation of microsomes with gallic acid in the presence of the NADPH generating system which generates reactive oxygen species (ROS) through cytochrome P-450 system increased the MGST1activity in spite of scavenging the ROS and the increase was also depressed by SOD/catalase. The increase of MGST1 activity by gallic acid was prevented by co-incubation with a stable radical, 1,1-diphenyl-2-picrylhydrazyl or ferric chloride. These results suggest that the gallic acid acts as a pro-oxidant and activates MGST1 through oxidative modification of the enzyme.

Thermolysis of polyethylene hydroperoxides in the melt 4. Effect of phenolic antioxidants and temperature on oxidation product formation

Phenolic antioxidants mostly lead to reduction of the oxidation product formation rate. This is similar to the effect of the phenols on the rate of thermolysis of polyethylene hydroperoxides in the melt. The most distinctive feature between the different products of hydroperoxide decomposition pertains to the maximum amount formed. For alcohol groups this maximum amount is lower in the presence of phenolic antioxidants than in their absence. For carbonyl groups it is the opposite. Formation of γ-lactones seems least affected by the presence of the antioxidants. Formation of trans-vinylene groups is most affected as the maximum amount formed is approximately doubled in the presence of phenolic antioxidants. Vinyl groups can be measured only in the presence of phenolic antioxidants. The effect of temperature on product formation has been determined mainly with the “initial linear” rates, the rates calculated according to the first-order rate equation showing too much scattering. The activation energy for alcohol group formation is practically the same in the absence and presence of phenolic antioxidants. It is comparable to the activation energy of pseudo-monomolecular hydroperoxide decomposition in polyethylene melts. The situation is different for carbonyl groups. In fact, the activation energy is depending heavily on the initial hydroperoxide concentration, much more than on the presence of phenolic antioxidants. It increases from 21 to 27 kcal/mol (88 to 113 kJ/mol) if polyethylene processing in air at 150 °C has been performed for 60 min instead of only 30 min. The activation energy for γ-lactone formation does not depend on the presence of phenols. For trans-vinylene groups, the activation energy seems to increase with the initial hydroperoxide concentration in the absence of phenols. This effect is much less pronounced in the presence of phenols. The most reliable value for the activation energy of vinyl group formation is close to 26 kcal/mol (109 kJ/mol).

Effects of phenolic antioxidants on ultrahigh molecular weight polyethylene/decalin solution

The degradation of ultrahigh molecular weight polyethylene (UHMW-PE) during its dissolution into decalin is discussed. The stabilization of the solution by three phenolic antioxidants, octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (1076), tetrakis[methylene-β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane (1010), and 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane (CA), and an auxiliary antioxidant, dilaurylthiodipropionate (DLTP) is also discussed. Among the three phenolic antioxidants, 1076 had the greatest effect. The auxiliary antioxidant was effective in stabilizing the solution when combined with one of the three phenolic antioxidants. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2877–2881, 2000

Protective effect of phenolic antioxidants on the cytotoxicity induced by phosphatidylcholine hydroperoxide.

Phosphatidylcholine hydroperoxides show weak but distinct toxicity toward cultured human umbilical vein endothelial cells. The protective effect of phenolic antioxidants against the cytotoxicity of phosphatidylcholine hydroperoxides was examined. Probucol depressed the toxicity most effectively among the antioxidants studied under both pretreatment and concurrent treatment conditions. alpha-Tocopherol showed a protective effect in the case of concurrent treatment. Protection by phenolic antioxidants against the cytotoxicity of phosphatidylcholine hydroperoxides seems to depend on their incorporation rate into cells, their affinity for phospholipids, their antioxidative activity, and their orientation in membranes.

Effects of phenolic antioxidants and flavonoids on DNA synthesis in rat liver, spleen, and testis in vitro

Paracetamol (acetaminophen) and hydroxyurea were found to inhibit DNA synthesis in a dose-dependent manner in tissue slices in vitro, with little effect on protein synthesis. Considerable variation in the sensitivity of the different tissues was also observed with an order of least sensitive to most sensitive tissue of liver < testis < spleen. The phenolic antioxidant properties of paracetamol are thought to be the mechanism by which paracetamol inhibits DNA synthesis, which led us to study other phenolic antioxidant molecules and flavonoids for specific inhibition of DNA synthesis. (+)-catechin, m-aminophenol, p-aminophenol and p-cresol all displayed a highly specific inhibition of DNA synthesis. Quercetin displayed a preferential inhibition of DNA synthesis but a significant level of inhibition of protein synthesis was also seen. Nordihydroguaiaretic acid (NDGA) and n-propyl gallate showed preferential inhibition of DNA synthesis at the lower doses tested, but at higher doses showed significant inhibition of protein synthesis, presumably because of cytotoxicity. Caffeic acid and naringenin did not display any specific inhibition of DNA synthesis as protein synthesis was equally inhibited at all doses tested. This study demonstrates that certain phenolic antioxidants can inhibit DNA synthesis specifically but this is not a property shared by all phenolic antioxidants; and that these inhibitors show considerable variation in effectiveness between different tissues.

Substrate-dependent effect of phenolic antioxidants on Ca2+ accumulation by rat liver mitochondria

The effect of different phenolic antioxidants on mitochondrial Ca2+capacity (maximum amount of Ca2+ mitochondria can accumulate) was studied. Butylated hydroxytoluene substantially enhanced the Ca2+ capacity in mitochondria oxidizing succinate, butylated hydroxyanisole had a moderate effect while 2,5-di-(t-butyl)-1,4 benzohydroquinone did not affect Ca2+ capacity at all. The analysis of Ca2+ accumulation in mitochondria oxidizing succinate in the presence of 2,5-di-(t-butyl)-1,4 benzohydroquinone revealed inhibition of the rate of Ca2+ accumulation. This effect was absent when ATP hydrolysis or NAD+-dependent substrate oxidation supported Ca2+ transport. Direct measurements of oxygen consumption revealed the concentration-dependent inhibition of succinate oxidation by increasing concentrations of 2,5-di-(t-butyl)-1,4 benzohydroquinone. When succinate was substituted by NAD+-dependent respiratory substrates, the Ca2+ capacity of mitochondria with 2,5-di-(t-butyl)-1,4 benzohydroquinone was even higher than in the presence of butylated hydroxytoluene.

Recycling and redox cycling of phenolic antioxidants.

Effectiveness of phenolic antioxidants in protecting against oxidative stress depends on their reactivity towards reactive oxygen species and the reactivity of the antioxidant phenoxyl radicals towards critical biomolecules. Reduction of phenoxyl radicals by intracellular reductant (ascorbate, thiols) as well as by enzymes or intermediates of electron transport (e.g., in mitochondria and the endoplasmic reticulum) recycles phenolic antioxidants, thus enhancing antioxidant protection. Several cascades may be involved in physiologically relevant recycling of vitamin E from its phenoxyl radicals. The two major ones are dihydrolipoic acid-->(GSH)-->ascorbate, and enzymes of electron transport-->coenzyme Q. Importantly, phenoxyl radicals of vitamin E are not directly reduced by intracellular thiols. By contrast, a number of natural phenolic compounds that act as very effective scavengers of reactive oxygen species and organic radicals, may generate reactive secondary radicals of antioxidants. These secondary radicals react and modify critical intracellular targets (lipids, proteins, and DNA). As a result, the role of these phenolic compounds as biological antioxidants may be limited because of their ability to cause cyto- and genotoxic effects. Typical examples are some estrogens and phenolic drugs (e.g., the antitumor drug, etoposide) that can protect lipids but oxidize GSH and protein sulfhydryls. Moreover, phenoxyl radicals produced in the course of radical scavenging by some phenolic compounds (e.g., phenol) are capable of oxidizing both proteins and lipids. Hence, reactivity of phenoxyl radicals should be considered as a critical factor in the development of new antioxidant protectants.

ESR study on chemical crosslinking reaction mechanisms of polyethylene using a chemical agent—II. The effect of phenolic antioxidants

ESR study on chemical crosslinking reaction mechanisms of polyethylene using a chemical agent—II. The effect of phenolic antioxidants