Effect of calixarenes on thermal stability of polyethylenes
TL;DR: In this article, the thermal degradation of polyethylenes (one type of high density PE and two of low-density PE) was studied by isothermal chemiluminescence.
About: This article is published in Polymer Degradation and Stability.The article was published on 2003-01-01. It has received 22 citations till now. The article focuses on the topics: Thermal stability & Thermal oxidation.
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TL;DR: In this article, a novel antioxidant with high molecular weight was successfully synthesized via horseradish peroxide-catalyzed oxidative polymerization of pyrogallic acid, which is a black powder completely soluble in common organic solvents, has a number-averaged molecular weight of about several thousand and consists of phenylene and oxyphenylene units.
Abstract: A novel antioxidant with high molecular weight was successfully synthesized via horseradish peroxide-catalyzed oxidative polymerization of pyrogallic acid. As-synthesized poly(pyrogallic acid), a black powder completely soluble in common organic solvents, has a number-averaged molecular weight of about several thousand and consists of phenylene and oxyphenylene units. Besides, as-prepared poly(pyrogallic acid) exhibits much better thermal stability and antioxidant capacity than butylated hydroxyanisole (denoted as BHA) and butylated hydroxytoluene (denoted as BHT), two kinds of commercial antioxidants. And it was also found that the higher phenolic content the pyrogallic acid polymer possess, the better antioxidant activity the poly(pyrogallic acid) shows. More importantly, poly(pyrogallic acid) could effectively inhibit the oxidation degradation of polypropylene (denoted as PP) during plastic processing. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41591.
16 citations
TL;DR: In this article, the authors investigated the thermal decomposition kinetics of calix[4]arene (C4) using thermogravimetric analysis (TGA) and derivative of TG curve (DTG).
13 citations
TL;DR: In this paper, the activation energy (Ea) and preexponential factors (ln A) of calix[6]arene (C6 and C8) were evaluated using both model-free and model-fitting methods.
Abstract: Thermal decomposition kinetics of calix[6]arene (C6) and calix[8]arene (C8) were studied by Thermogravimetry analysis (TG) and Differential thermal analysis (DTA). TG was done under static air atmosphere with dynamic heating rates of 1.0, 2.5, 5.0, and 10.0 K min−1. Model-free methods such as Friedman and Ozawa–Flynn–Wall were used to evaluate the kinetic parameters such as activation energy (Ea) and pre-exponential factors (ln A). Model-fitting method such as linear regression was used for the evaluation of optimum kinetic triplets. The kinetic parameters obtained are comparable with both the model-free and model-fitting methods. Within the tested models, the thermal decomposition of C6 and C8 are best described by a three dimensional Jander’s type diffusion. The antioxidant efficiency of C6 and C8 was tested for the decomposition of polypropylene (PP).
12 citations
Cites background from "Effect of calixarenes on thermal st..."
...Calix[n]arenes are good antioxidants for the oxidation of polyolefins such as polypropylene, lowdensity polyethylene and high-density polyethylene [8–12]....
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TL;DR: In this paper, the authors used FTIR, UV-Vis, XRD, SEM, and TEM techniques to evaluate the conductivity of polyaniline and thiacalix tetra sulfonate (TCAS) nanocomposites.
Abstract: Nanocomposites of polyaniline (PANI) and the macrocycle thiacalix[4]arene tetra sulfonate (TCAS) were successfully synthesized in feed ratios of 1:0.25, 1:0.50 and 1:0.75 by three prevail synthetic methods, i.e. in situ polymerization, emulsion polymerization and solution casting technique. The structures of the nanocomposites were confirmed by FTIR, UV-Vis, XRD, SEM, and TEM techniques. The conductivity was measured by a four probe method. The conductivity was recorded to be as high as 105 × 10−2 S·cm−1 for the nanocomposite with a nanometer size structure and homogeneously distributed morphology. The electroactivity of the nanocomposites was approved by cyclic voltammetry (CV) and impedance spectroscopy technique (EIS). The antioxidant ability and thermal property of the composites were further studied. Preliminary studies have evidenced the production of conductive nanocomposites with good thermal property and relatively good solubility in N-methyl 2-pyrrolidone (NMP), with the antioxidant activity reaching up to 80%.
11 citations
TL;DR: In this article, the thermal properties of calixarene-derived cyanate ester resins, both single and binary systems, were synthesized and studied for their thermal properties.
Abstract: p-tert-Butylcalix[4]arene-derived cyanate ester resins, both single and binary systems, were synthesized and studied for their thermal properties. The results showed that pure calixarene cyanate es...
10 citations
Cites background or methods from "Effect of calixarenes on thermal st..."
...XRD tests showed that in calixarenes synthesis, linear prepolymer forms larger rings of calix[8]arene at a lower temperature; with an increase of reaction temperature, larger rings turn into calix[6]arene and calix[4]arene in sequence; at a temperature of 200 C, calixarenes of various sizes turn into calix[4]arene....
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...Calix[4]arene, calix[6]arene, and calix[8]arene have comparably similar spectrum, the broad peak at 3169 cm 1 is the stretching vibration peak of O–H; 2955 cm (1), 2900 cm (1), and 2869 cm 1 correspond to vibration peak of C–H in CH3 and CH2; 1200 cm 1 corresponds to stretching vibration of phenolic C–O, which suggests that these three calixarenes have hardly identified infrared characteristics....
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...19 nm in diameter, suggesting that at a reaction temperature of 160 C, calix[8]arene transforms into mainly calix[6]arene and much little calix[4]arene....
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...Calix[6]arene and calix]arene were also prepared with the similar procedure....
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...p-tert-butylcalix[4]arene, p-tert-butylcalix[6]arene, and p-tert-butylcalix[8]arene, respectively)....
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References
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27 Sep 2011
TL;DR: In this paper, the authors present a single-step approach to synthesize Calixarenes in the solid state and show the properties of the resulting Calix-arenes.
Abstract: One: History and Synthesis of Calixarenes.- Single Step Synthesis and Properties of Calixarenes.- 1. Introduction.- 2. Single Step Synthesis of Calixarenes.- 2.1. Base-Induced Procedures.- 2.2. Acid-Catalyzed Procedures.- 2.3. Thermally Induced Procedures.- 3. Synthesis of Functionalized Calixarenes.- 3.1. Introduction of Substituents on the 'Lower Rim' of Phenol-Derived Calixarenes.- 3.1.1. Ester and Ether Formation with Monofunctionalized Reagents.- 3.1.2. Esterification and Etherification with Polyfunctionalized Reagents.- 3.2. Introduction of Substituents on the 'Upper Rim' of Phenol-Derived Calixarenes.- 3.2.1. Dealkylation of p-Alkylcalixarenes.- 3.2.2. Electrophilic Substitution Route.- 3.2.3. p-Claisen Rearrangement Route.- 3.2.4. p-Quinonemethide Route.- 3.2.5. p-Chloromethylation Route.- 3.3. Introduction of Substituents at the 'Upper Rim' of Resorcinol-Derived Calixarenes.- 3.4. Introduction of Functional Groups at the Methylene Bridges of Calixarenes.- 4. Physical Properties of Calixarenes.- 4.1. Melting Points.- 4.2. Solubilities.- 4.3. Spectral Properties of Calixarenes.- 4.3.1. Infrared Spectra.- 4.3.2. Ultraviolet Spectra.- 4.3.3. NMR Spectra.- 4.3.4. Mass Spectra.- 5. Concluding Comments.- References.- Special Calixarenes, Synthesis and Properties.- 1. Introduction.- 2. Stepwise Synthesis of Calixarenes.- 3. Fragment Condensation.- 4. Selective Functionalization.- 5. The First Acidity Constant of Calix[4]arenes.- 6. Chiral Calix[4]arenes.- 7. Bridged Calixarenes.- 8. Double Calixarenes and Future Directions.- References.- Two: X-Ray Structural Data on Calixarene Architectures.- Conformations of Calixarenes in the Crystalline State.- 1. Introduction.- 2. Conformations and Structures of Some Precursors.- 3. Conformations of Calixarenes.- 3.1. Introduction.- 3.2. Conformations of Calix[4]arenes.- 3.2.1. Calix[4]arenes with a Fourfold Axis.- 3.2.3. Calix[4]arenes with Symmetry Planes.- 3.2.3. Calix[4]arenes with a Twofold Axis.- 3.2.4. Calix[4]arenes in the Cone Conformation with No Particular Symmetry.- 3.3. Conformations of Calix[5]arenes.- 3.4. Conformations of Calix[6]arenes.- 3.4.1. Calix[6]arenes with Symmetry Planes.- 3.4.2. Calix[6]arenes in the Centrosymmetrical Conformation.- 3.5. Conformations of Calix[7]arenes.- 3.6. Conformations of Calix[8]arenes.- 3.6.1. Calix[8]arenes with Mirror Planes.- 4. Conclusion.- References.- Inclusion Properties and Host-Guest Interactions of Calixarenes in the Solid State.- 1. Introduction.- 1.1. General Considerations.- 1.2. Conformational Properties of Calixarenes in the Solid State.- 2. Conformational Preferences in Functionalized Calixarenes.- 2.1. Calix[4]arenes.- 2.2. Calix[6]arenes.- 2.3. Calix[8]arenes.- 2.4. Calixarene Cavitands.- 3. Metallocalixarenes.- 4. Calixarene Based Cation Carriers and Receptors.- 5. Molecular Inclusion of Neutral Molecules by Calixarenes.- 5.1. Intramolecular Complexes of Calixarenes.- 5.2. Cage Complexes.- 5.3. Intermolecular Complexes.- 5.4. Clathrates.- 6. Theoretical Models for the Host-Guest Interactions.- Acknowledgements.- References.- Three: Inclusion Properties of Calixarenes and Their Derivatives.- Calixarene-Based Cation Receptors and Carriers.- 1. Introduction.- 2. Calixarene Podands with Ether Chains.- 3. Calixarene Podands with Ester and Amide Groups.- 4. Calixcrowns and Calixspherands.- 5. Ionizable Calixarene Ligands.- 6. Concluding Remarks.- Acknowledgements.- References.- Chemically Modified Calixarenes as New Selective Receptors for Monovalent Cations.- 1. Introduction.- 2. Calixarenes as Receptor Substructures.- 3. Chemically Modified Calixarenes.- 4. Complexation of Alkali Cations: Phase Transfer, Stability Constants, Selectivities, and Transport.- 4.1. Calixarene Esters and Ketones.- 4.1.1. Extraction Experiments.- 4.1.2. Stability Constants.- 4.1.3. Complexation Selectivities.- 4.1.4. Ion Transport.- 4.2. Calixarene Amides.- 4.3. Calixarenes with Mixed Ligating Functional Groups.- 4.4. Relation between Physicochemical Properties and Molecular Structure.- 5. Conclusions and Perspectives.- Acknowledgements.- References.- Functionalized Calixarenes: New Applications as Catalysts, Ligands, and Host Molecules.- 1. Introduction.- 2. Syntheses of Functionalized Calixarenes.- 3. Conformational Properties.- 4. Acidity Constants of the Phenolic Hydroxyl Groups.- 5. Aggregation and Inclusion Phenomena.- 6. Chiral Calixarenes.- 7. Ionophoric Calixarenes.- 8. Conclusions.- References.- Water Soluble Calixarene Salts. A Class of Compounds with Solid-State Structures Resembling Those of Clays.- 1. Introduction.- 2. The [Calix[4]arene Sulfonate]5- Anion.- 2.1. Na5[Calix[4]arene Sulfonate].- 2.2. Other Alkali Salts.- 2.3. Transition Metals and Lanthanides.- 2.4. Inclusion of Organic Species.- 3. The [Nitrocalix[4]arene]2- Anion.- 4. The [Calix[4]arene Sulfonate Methyl Ether]4- Anion.- References.- Lanthanide Ions and Calixarenes.- 1. Introduction.- 2. Lanthanide Ions and p-fert-Butylcalixarenes.- 2.1. Synthesis and Stoichiometry.- 2.1.1. Complexes of p-tert-Butylcalix[8]arene.- 2.1.2. Complexes of p-tert-Butylcalix[6]arene.- 2.1.3. Complexes of p-tert-Butylcalix[4]arene and p-tert-Butylbishomooxacalix[4]arene.- 2.2. Solid State Structures - X-Ray Crystallography.- 2.2.1. Complexes of p-tert-Butylcalix[8]arene.- 2.2.2. Complexes of p-tert-Butylcalix[6]arene.- 2.2.3. Complexes of p-tert-Butylcalix[4]arene.- 2.3. Solution Structure.- 2.4. Luminescence Spectroscopy.- 3. Conclusions.- Acknowledgements.- References.- Four: Industrial Applications.- Industrial Applications of Calixarenes.- 1. Introduction.- 2. Recovery of Cesium.- 3. Recovery of Uranium.- 4. Further Ion Sequestering Possibilities.- 5. Ion Selective Electrodes and Field Effect Transistors.- 6. Phase Transfer Agents.- 7. Accelerators for Instant Adhesives.- 8. Ion Scavengers for Electronic Devices.- 9. Stabilizers for Organic Polymers.- 10. Separation of Neutral Organic Molecules.- 11. Hydrolysis Catalysts.- 12. Langmuir-Blodgett Films and Membranes.- 13. Polymer-Bound Calixarenes.- 14. Concluding Remarks.- References.- List of Contributors.
939 citations
01 May 2000
TL;DR: Calixarenes in Action as discussed by the authors is a reference book for researchers in organic, inorganic, analytical and environmental chemistry and can serve as a graduate-level text for students of supramolecular science and technology.
Abstract: Calixarenes in Action is unique among books devoted to this interesting class of synthetic macrocycles. Rather than emphasizing the molecular properties of calixarenes, it covers in depth their supramolecular functions, enlightening the reader as to the peculiar features of calixarenes as hosts and as platforms for the synthesis of more complex receptors and catalysts. Topics covered in detail include the use of calixarenes in:molecular modeling of calixarenesnon-covalent interactionscrystal engineeringcation recognitionanion recognitionsupramolecular devicesnew materialsself-assembly processessupramolecular catalysisThe interest in calixarenes has grown tremendously in the last few years and this book reports, for each topic, the most recent literature critically evaluated by active researchers in the field. Calixarenes in Action is a valuable reference book for researchers in organic, inorganic, analytical and environmental chemistry and can serve as a graduate-level text for students of supramolecular science and technology.
543 citations
TL;DR: It was found that these calix[6]arene derivatives efficiently accelerate acid-catalyzed hydration of I-benzyl1,4-dihydronicotinamide and the reaction proceeds according to the Michaelis-Menten kinetics, indicating that hexasulfonated calixarenes serve as a new class of catalysts, surfactants, and host molecules.
Abstract: Water-soluble hexasulfonated calix[6]arenes with various substituents (I-R) have been synthesized for the first time and applied as host molecules in an aqueous system. Dynamic ‘H NMR studies established that calb[6]arene-p-hexasulfonate (1-H) adopts a “winged” or “hinged” conformation in D20-Me2SO-d6 (2:l v/v) owing to hydrogen bonding among the OH groups, while 5,11,17,23,29,35-hexasulfonato-37,38,39,40,41,42-hexakis(hexyloxy)calix[6]arene (l-C6) adopts a similar conformation in D20 owing to hydrophobic bonding among the hexyl groups. The aggregation behavior in water was examined about I-C6 and I-C12. Physical (light-scattering, surface tension, and conductance) and spectral (fluorescence and absorption spectroscopies) studies established that 1-C, has a cmc at ca. 6 X IO4 M, as does sodium dodecyl sulfate (SDS), while I C l 2 has no detectable cmc and rather acts as a “unimolecular” micelle. In fact, l-C6 associated with small molecules (pyrene, 2-anilinonaphthalene, and Orange OT) according to the micelle-like biphasic concentration dependence, while 1-C12 formed host-guest-type 1: 1 complexes with these molecules. It was found that these calix[6]arene derivatives efficiently accelerate acid-catalyzed hydration of I-benzyl1,4-dihydronicotinamide and the reaction proceeds according to the Michaelis-Menten kinetics. In particular, the rate constants for 1-H and 1-CH2COOH, which both have acidic protons to catalyze the reaction and anionic sulfonates to stabilize the cationic intermediate at the two edges of the cavity, were greater by 426-1220-fold than those for noncyclic analogues. These findings indicate that hexasulfonated calix[6]arenes serve as a new class of catalysts, surfactants, and host molecules. This is the first example for the host-guest-type behavior of calixarenes observed in an aqueous system. The chemistry of cyclodextrins and cyclophanes has occupied a central interest in host-guest chemistry for the last two decades, and many functionalized host molecules which can mimic the in vivo action of enzymes by means of simple in vitro chemical systems have been exploited.2d Recently, Gutsche and coworker~’,~ have reported on a series of new cyclic molecules called “calixarenes” which are cyclic oligomers made up of benzene units as cyclodextrins are made up of glucose units. Since calixarenes possess a cylindrical architecture similar to cyclodextrins, they are expected to be useful to design enzyme mimics in totally synthetic systems.’.* Several groups have reported on the ionophoric properties of calixarenes which were obtained by introducing ether and/or ester groups into the edge of the cylindrical a rch i te~ture .~’~ In contrast, almost nothing is known with certainty as to the inclusion properties of calixarenes in solution, which should be more important in the design of the enzyme mimics. The data reported so far have been limited to only the solid and in fact, Gutsche stated in his recent review (1) Preliminary communications: (a) Shinkai, S.; Mori, S.; Tsubaki, T.; Sone, T.; Manabe, 0. Tetrahedron L e f f . 1984, 25, 5315. (b) Shinkai, S.; Koreishi, H.; Mori, S.; Sone, T.; Manabe, 0. Chem. Letf. 1985, 1033. (2) Breslow, R. Acc. Chem. Res. 1980, 13, 170. (3) Tabushi, I. Acc. Chem. Res. 1982, 15, 66. (4) Komiyama, M.; Hirai, H. J . Am. Chem. SOC. 1983, 105, 2018. (5) Bender, M. L.; Komiyama, M. In ‘Cyclodextrin Chemistry”; Spring(6) Murakami, Y. ‘Cyclophanes 11”; Springer-Verlag: Berlin, 1983; p 107. (7) Gutsche, C. D. Arc. Chem. Res. 1983, 16, 161. (8) Gutsche, C. D. In “Host Guest Complex Chemistry/Macrocycles”; (9) Chang, S.-K.; Cho, I. Chem. Lett. 1984, 477. (10) Ungaro, R.; Pochini, A.; Andreetti, G. D. J. Inclusion Phenom. 1984, er-Verlag: New York, 1977. Springer-Verlag: Berlin, 1985, p 375. 2. 199. -, . (1 1) Bocchi, V.; Foina, D.; Pochini, A,; Ungaro, R.; Andreetti, G. D. (12) McKervey, M. A.; Seward, E. M.; Ferguson, G.; Ruhl, B.; Harris, S. Tetrahedron 1982, 38, 373. J. J . Chem. SOC., Chem. Commun. 1985, 388. (1 3) Calixarenes can extract certain metal cations into the organic phase as their counterions: (a) Izatt, R. M.; Lamb, J. D.; Hawkins, R. T.; Brown, P. R.; Izatt, S. R.; Christensen, J. J. J. Am. Chem. Soc. 1983, 105, 1782. (b) Izatt, S. R.; Hawkins, R. T.; Christensen, J. J.; Zatt, R. M. Ibid. 1985, 107, 63. (14) Andreetti, G. D.; Ungaro, R.; Pochini, A. J. Chem. Soc., Chem. Commun. 1979, 1005. (15) (a) Coruzzi, M.; Andreetti, G. D.; Bocchi, V.; Pochini, A,; Ungaro, R. J . Chem. Soc., Perkin Trans. 2 1982, 1133. (b) Ungaro, R.; Pochini, A,; Andreetti, G. D.; Domiano, P. Ibid. 1985, 197. 0002-7863/86/ 1508-2409$01.50/0 article that there are no published data in support of solution complexes of calixarenes.8*16 This is in sharp contrast to cyclodextrins, which can form a variety of host-guest-type solution complexes. We noticed that the difference would stem mainly from the poor solubility of calixarenes; they are sparingly soluble in several organic solvents but insoluble in aqueous solutions. Therefore, the experimental efforts should be directed toward solubilization of calixarenes, which would eventually lead to tHe exploitation of calixarene-based host molecules and enzyme mimics. Here, we wish to report the synthesis and the solution properties of new water-soluble hexasulfonated calix[6]arenes (1-R). We have found that they serve not only as host molecules in an aqueous system but also as a new class of surfactants and acid catalysts.
433 citations
TL;DR: In this paper, an exhaustive review of calixarenes containing transition metals is presented, with a focus on synthetic aspects, to allow the reader to acquire a useful knowledge of the construction of transition metal complexes derived from calixarens.
350 citations
320 citations