Article

Synthesis Of Poly Vinyl Chloride/Chlorinated Polypropylene-Active Natural Substance Derivatives For Potential Packaging Materials Application. Tannic Acid, Menthol And Lipoic Acid

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Abstract

A novel one step route for the synthesis of tannic acid, lipoic acid and menthol functionalized polyvinyl chloride, PVC, (PVC-Tann, PVC-Lip, PVC-Mnt) and chlorinated polypropylene, PP-Cl, (PP-Mnt, PP-Lip) was applied imparting antioxidative properties to the newly-formed materials. The resulting modified polymers were characterized by stress-strain mechanical measurement, ¹H NMR, gel permeation chromatography (GPC) and thermogravimetric (TGA) analysis. Linseed oil, owing to its high linolenic acid content, was used to track the autoxidation process. The chloride functional groups were reacted with the hydroxyl /carboxylic acid of the natural compounds in the presence of a base. Linseed oil was poured into the natural compound functionalized PVC covered Petri dish to undergo autoxidation under white light. Each of the PVC- and PP-Cl-based polymers was active in delaying autoxidation. The PP-Mnt series and PP-Lip polymers all delayed autoxidation by 8 days over the PP-Cl precursor material. The autoxidation process was further confirmed by monitoring peroxide formation in the exposed linseed oil samples through differential scanning calorimeter (DSC) analysis.

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... As one of the important polymers in the world, the annual output of polyvinyl Chloride (PVC) is second only to polyethylene (PE), and it is favored by people in the fields of automobile manufacturing, building decoration, children's toys, and outdoor protective materials [1][2][3][4].Additionally, the PVC derivatives also have been used as active packaging materials [5,6]. The reason is that PVC has good mechanical properties, acid and alkali resistance, insulation, flame retardant, and so on. ...
... Thus, the Hansen sphere of PVC is obtained. At the same time, the points of the plasticizers in the coordinates are also calculated, and the distance (R a ) from the point of plasticizer to the point of PVC is calculated according to Equation (6). The results also listed in Table 2, and the Hansen sphere is shown in Figure 9. ...
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This Perspective describes advances from the author's laboratory on the free radical reactions of organic compounds with molecular oxygen. Polyunsaturated fatty acids (PUFAs) and sterols are particularly prone to undergo radical chain oxidation and evidence suggests that this process, known as lipid peroxidation, occurs in vivo under a variety of conditions that are the result of an oxidative stress. Cyclic peroxides, hydroperoxides, and epoxy-alcohols are major products formed from peroxidation and the basic mechanisms of product formation are now reasonably well understood. These mechanisms include reversible addition of oxygen to carbon radicals, rearrangement and cyclization of allyl and pentadienyl peroxyl radicals and homolytic substitution of carbon radicals on the peroxide bond. A physical organic approach to the problem of free radicals in biology and medicine is highlighted in this Perspective with stereochemical, kinetic and extrathermodynamic probes applied to the study of mechanism. A radical clock permits the determination of free radical propagation rate constants and 7-dehydrocholesterol, the immediate biosynthetic precursor of cholesterol, is found by this clock to be one of the most oxidizable lipids known. The consequences of the extreme reactivity of 7-dehydrocholesterol on human health is the focus of a current research theme in the author's laboratory.
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The autoxidation of soybean oil in a cyclodextrin emulsion system was studied in the presence of an emulsion stabilizer consisting of polysaccharides such as xanthan, tragacanth gum, and methylcellulose. Xanthan strongly inhibited the peroxidation of soybean oil containing tocopherols but showed no antioxidant activity on soybean oil without tocopherols in the emulsion. Xanthan did not have hydrogen-donating ability but expressed Fe2+-binding activity. The Fe2+-binding activity corresponded to the pyruvate content of xanthan. Depyruvated xanthan did not inhibit effectively the autoxidation of soybean oil. The Fe2+-chelating structure of xanthan is discussed.
Article
Triglycerides with acrylate functionality were prepared from a new route that involves the singlet oxygen photooxygenation of high oleic sunflower oil and further reduction of the resulting hydroperoxide derivatives to a mixture of secondary allylic alcohols. These unsaturated alcohols can be further reduced to saturated alcohols. These two new hydroxyl-containing triglycerides were functionalized as acrylate esters and radically crosslinked in presence of different amounts of pentaerythritol tetraacrylate. The crosslinking reactions were followed by FTIR spectroscopy and the thermal properties of the final materials were evaluated. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1159–1167, 2009
Article
The photoinduced graft copolymerization of acrylic acid with ultraviolet radiation onto films of poly(vinyl chloride), polypropylene, and polyethylene was studied. Benzophenone was used as the initiator for most of the experiments performed. The percentage of grafting was determined by gravimetric measurements, and the characterization of the grafted films was carried out by chemical analysis (Fourier transform infrared spectroscopy, volumetric titration, and dye adsorption). In all samples, the grafted yield increased with the ultraviolet exposure time. High levels of grafting were obtained at room temperature. In addition, optical and atomic force microscopy allowed the topography of the modified films to be studied as a function of the reaction time. The pendant functional groups that were grafted were then used to bind antifungal agents, such as natamycin and crystal violet, and the antifungal properties of the films were demonstrated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:2254–2263, 2006
Article
‘Active and intelligent’ (A&I) food packaging is based on a deliberate interaction of the packaging with the food and/or its direct environment. This article presents: (i) the main types of materials developed for food contact; (ii) the global market and the future trends of active and intelligent packaging with a special emphasis on safety concerns and assessment; and (iii) the EU Legislation and compliance testing of these novel food packaging technologies.
Article
Edible oil is oxidized during processing and storage via autoxidation and photosensitized oxidation, in which triplet oxygen (3O2) and singlet oxygen (1O2) react with the oil, respectively. Autoxidation of oils requires radical forms of acylglycerols, whereas photosensitized oxidation does not require lipid radicals since 1O2 reacts directly with double bonds. Lipid hydroperoxides formed by 3O2 are conjugated dienes, whereas 1O2 produces both conjugated and nonconjugated dienes. The hydroperoxides are decomposed to produce off-flavor compounds and the oil quality decreases. Autoxidation of oil is accelerated by the presence of free fatty acids, mono- and diacylglycerols, metals such as iron, and thermally oxidized compounds. Chlorophylls and phenolic compounds decrease the autoxidation of oil in the dark, and carotenoids, tocopherols, and phospholipids demonstrate both antioxidant and prooxidant activity depending on the oil system. In photosensitized oxidation chlorophyll acts as a photosensitizer for the formation of 1O2; however, carotenoids and tocopherols decrease the oxidation through 1O2 quenching. Temperature, light, oxygen concentration, oil processing, and fatty acid composition also affect the oxidative stability of edible oil.
Article
The carboxylic acids derived from olive oil, hazelnut oil, sesame oil and hamci(anchovy) oil were evaluated as substrates for cell growth and the production of reserve polyesters by Pseudomonas oleovorans. Poly-3-hydroxy alkanoates containing both saturated(mainly 3-hydroxy-octanoate and 3-hydroxy-decanoate) and unsaturated repeating units with 8 to 20 carbon atoms, or more, were produced in 26 to 61% yields based on cell dry weights. The number average molecular weights of these polymers varied from 45,000 to 68,000 Daltons.
Article
The methanolic extracts of 16 Helichrysum species were investigated for their in vitro antioxidant, radical scavenging and antimicrobial activities. All the extracts showed strong antioxidant and radical scavenging activity. The highest total antioxidant capacity as ascorbic acid equivalents (AAE) of 194.64 mg/g dry extract was obtained for Helichrysum noeanum in the phosphomolybdenum assay. The highest IC50 value (7.95 μg/ml) was observed for the extract of Helichrysum stoechas subsp. barellieri in the DPPH assay. The total phenolic contents of the extracts ranged from 66.74 to 160.63 mg gallic acid equivalents (GAE)/g dry extract. The major component present in the extracts was identified as chlorogenic acid followed by apigenin-7-glucoside and apigenin by HPLC analysis. All the extracts showed significant antimicrobial activity against microorganisms containing 13 bacteria and two yeasts in the agar diffusion method.
Article
This paper reviews the antioxidant properties of tocopherols and ascorbic acid in edible oils, and the impact of interfacial phenomena on their activities in emulsions and the effects of edible oil processing. Tocopherols are the most important natural antioxidants found in vegetable oil-derived foods. These antioxidants can interrupt lipid autoxidation by interfering with either the chain propagation or the decomposition processes. α-Tocopherol at high concentrations inhibits hydroperoxide decomposition but promotes hydroperoxide formation. The effect of antioxidants in inhibiting hydroperoxide decomposition may thus be critical in preserving food quality by reducing rancidity due to aldehyde formation. Ascorbic acid can regenerate α-tocopherol, inactivate metal initiators and reduce hydroperoxides. The activity of natural antioxidants is greatly affected by complex interfacial phenomena in emulsions and multi-component foods. In an oil-in-water emulsion system, the lipophilic antioxidants α-tocopherol and ascorbyl palmitate are more effective than in bulk oil, while the opposite trend is found for the hydrophilic antioxidants Trolox and ascorbic acid. The methodology to evaluate natural antioxidants must be carefully interpreted depending on whether oxidation is carried out in bulk oils or in emulsions, and what method is used to measure lipid oxidation.
Article
The immobilization of caffeic acid (CA) on a polypropylene (PP) film was successfully performed through the covalent binding of the caffeoyl chloride on a modified polymeric surface of PP films grafted with hydroxyethyl methacrylate as monomer (PP-g-HEMA). The different reaction steps were monitored by FT-IR spectroscopy. The synthesized films were characterized by Folin-Ciocalteu method by measuring the available phenolic groups as caffeic acid equivalents linked to the surface. The antioxidant efficiency of the modified polymers was evaluated by typical spectrophometric methods, such as the bleaching of radicals DPPH(*) and ABTS(*+), and the inhibition of the enzymatically induced coupled oxidation of linoleic acid and betacarotene. The available phenolic groups on the modified film presented a good correlation with the antiradical activity toward DPPH(*). Moreover, the polymer synthesized in this work showed a good protective activity against ascorbic acid oxidation in real samples of orange juice.
Article
Active packaging technologies offer new opportunities for the food industry, in the preservation of foods. Important active packaging systems currently known to date, including oxygen scavengers, carbon dioxide emitters/absorbers, moisture absorbers, ethylene absorbers, ethanol emitters, flavor releasing/absorbing systems, time-temperature indicators, and antimicrobial containing films, are reviewed. The principle of operation of each active system is briefly explained. Recent technological advances in active packaging are discussed, and food related applications are presented. The effects of active packaging systems on food quality and safety are cited.
Article
Autoxidations of cis,cis, cis,trans, and trans,trans nonconjugated octadecadienoates and pentadecadienes were carried out in the presence of alpha-tocopherol to investigate the effect of olefin geometry on this oxidation process and provide insight into the factors that influence the autoxidation of fatty acids. We have found that as the trans character of the diene increases, the amount of O(2) trapping at the central (bis-allylic) position of the pentadienyl radical also increases. In addition, the rate constant for beta-fragmentation (k(beta) approximately 10(6) s(-1)) of the bis-allylic peroxyl radical decreased on going from the cis,cis to the trans,trans diene. We have also found that for the cis,trans nonconjugated dienes, there is a preference for trapping of the pentadienyl radical by O(2) at the transoid end, generating the cis,trans conjugated hydroperoxide as the major product.
Article
An overview is given of the potential uses, possibilities and successful applications of (-)- and (+)-menthol and its most prevalent derivatives in preparative organic synthesis. The nine most frequently used menthol derivatives are introduced namely, menthyloxy-2-[5H]-furanone, dimenthyl fumarate, dimenthyl succinate, menthyl glyoxylate, menthyl p-toluenesulfinate, methyl chloride, menthyl acrylate, menthyl diazoacetate and menthyl chloroformate. The applications of each derivative in asymmetric synthesis are outlined.
Evaluation of polyvinyl chloride functionalized with 3-(2-thiazolylazo)-2,6- diaminopyridine as a new chelating resin for on-line pre-concentration and determination of traces of cadmium in real samples by flame atomic absorption spectrometry
  • G Bagherian
  • A Pourbahramian
  • B Bahramian
  • M A Chajangali
  • M Ashrafi
Enzymatic Esterification of (−−)-Menthol with Lauric Acidin Isooctane by Sorbitan Mono stearate-Coated Lipase from Candida rugose
  • Babali
Evaluation of polyvinyl chloride functionalized with 3-(2-thiazolylazo)-2,6-diaminopyridine as a new chelating resin for on-line pre-concentration and determination of traces of cadmium in real samples by flame atomic absorption spectrometry
  • Bagherian
How to improve PET packaging for UV sensitive beverages
  • Polyone Corporation