scholarly journals Epoxidation of Cardanol’s Terminal Double Bond

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2104
Author(s):  
Emre Kinaci ◽  
Erde Can ◽  
John J. La Scala ◽  
Giuseppe R. Palmese
Keyword(s):  
Double Bond ◽  
Glycidyl Ether ◽  
Tensile Modulus ◽  
Mechanical Analysis ◽  
Side Chain ◽  
Double Bonds ◽  
Fiber Reinforced Composite ◽  
Terminal Double Bond ◽  
Reinforced Composite ◽  
Polymer Properties

In this investigation, the terminal double bonds of the side chain epoxidized cardanol glycidyl ether (SCECGE) molecule were further epoxidized in the presence of Oxone® (potassium peroxomonosulfate) and fluorinated acetone. Regular methods for the double bond epoxidation are not effective on the terminal double bonds because of their reduced electronegativity with respect to internal double bonds. The terminal double bond functionality of the SCECGE was epoxidized to nearly 70%, increasing the epoxy functionality of SCECGE from 2.45 to 2.65 epoxies/molecule as measured using proton magnetic nuclear resonance (1H-NMR). This modified material—side chain epoxidized cardanol glycidyl ether with terminal epoxies (TE-SCECGE)—was thermally cured with cycloaliphatic curing agent 4-4′-methylenebis(cyclohexanamine) (PACM) at stoichiometry, and the cured polymer properties, such as glass transition temperature (Tg) and tensile modulus, were compared with SCECGE resin cured with PACM. The Tg of the material was increased from 52 to 69 °C as obtained via a dynamic mechanical analysis (DMA) while the tensile modulus of the material increased from 0.88 to 1.24 GPa as a result of terminal double bond epoxidation. In addition to highlighting the effects of dangling side groups in an epoxy network, this modest increase in Tg and modulus could be sufficient to significantly expand the potential uses of amine-cured cardanol-based epoxies for fiber reinforced composite applications.

Extractives of Australian timbers. X. Autoxidation and other reactions of the conjugated side-chain of eberlin lactone. Isolation of a new isomer of ebelin lactone

1970 ◽  
Vol 23 (10) ◽  
pp. 2085 ◽  
Author(s):  
RA Eade ◽  
J Ellis ◽  
JS Shannon ◽  
HV Simes ◽  
JJH Simes
Keyword(s):  
Double Bond ◽  
Solid State ◽  
Osmium Tetroxide ◽  
Side Chain ◽  
Methyl Groups ◽  
Stepwise Manner ◽  
Terminal Double Bond ◽  
Conjugated Triene

The conjugated triene side-chain of ebelin lactone has been degraded in a stepwise manner using osmium tetroxide. A new isomer of ebelin lactone has been isolated from the sapogenin mixture and has been assigned the structure (9) in which the 25(26) double bond has the cis configuration. Autoxidation of ebelin lactone in the solid state yields a mixture from which three compounds have been isolated and identified; all three arise from oxidation of the side-chain at the terminal double bond and methyl groups.

Chemistry of amidyl radicals: intramolecular reactivities of alkenyl amidyl radicals

1985 ◽  
Vol 63 (8) ◽  
pp. 2203-2210 ◽  
Author(s):  
Yuan L. Chow ◽  
Richard A. Perry
Keyword(s):  
Double Bond ◽  
Rate Constants ◽  
Side Chain ◽  
Double Bonds ◽  
Kinetic Rate ◽  
Cyclic Radical ◽  
Kinetic Rate Constants ◽  
Acyl Side Chain ◽  
Complete Reversal

Amidyl radicals possessing Δ4,5, Δ5,6, and Δ6,7 double bonds were generated from the photodecomposition of nitrosamides and chloramides and the products were identified. Dichotomies of amidyl radical reactivities were discovered and compared with published kinetic rate constants. In complete reversal to intermolecular reactivities, intramolecularly the alkenyl amidyl radicals preferentially add to the double bonds rather than abstract a C-5 hydrogen even if it is allylic. In intramolecular competition, amidyl radicals add to an acyl side chain double bond more efficiently than to an alkyl one; this is just the opposite to intramolecular H-abstraction of amidyl radicals. Taken together with the published results, it is established that, in intramolecular attacks of double bonds, amidyl radicals selectively undergo the propia-addition to generate an exo-cyclic radical rather than the longa-addition to an endo-cyclic radical: this rule should replace the old one that amidyl radicals preferentially cyclize to form five-membered rings if choices are available.

Transformations of Steroids by Beauveria bassiana

2005 ◽  
Vol 60 (1-2) ◽  
pp. 103-108 ◽  
Author(s):  
Ewa Huszcza ◽  
Jadwiga Dmochowska-Gładysz ◽  
Agnieszka Bartmańska
Keyword(s):  
Double Bond ◽  
Beauveria Bassiana ◽  
Hydroxyl Group ◽  
Side Chain ◽  
Double Bonds ◽  
Methyl Group ◽  
Group Reduction ◽  
Group A ◽  
Acetyl Group

The course of transformations of testosterone and its derivatives, including compounds with an additional C1,C2 double bond and/or a 17α-methyl group, a 17β-acetyl group or without a 19-methyl group, by a Beauveria bassiana culture was investigated. The fungi promoted hydroxylation of these compounds at position 11α, oxidation of the 17β-hydroxyl group, reduction of the C1,C2 or C4,C5 double bonds and degradation of the progesterone side-chain, leading to testosterone. The structure of 4-ene-3-oxo-steroids had no influence on regio- and stereochemistry of hydroxylation. In a similar manner, dehydroepiandrosterone was hydroxylated by Beauveria bassiana at position 11α, however, a small amount of 7α- hydroxylation product was also formed.

Measurement of Internal Double Bonds in Polymers by Perbenzoic Acid Addition

1948 ◽  
Vol 21 (4) ◽  
pp. 821-829 ◽  
Author(s):  
Alfred Saffer ◽  
B. L. Johnson
Keyword(s):  
Double Bond ◽  
Low Ph ◽  
Side Chain ◽  
Double Bonds ◽  
Extrapolation Procedure ◽  
Perbenzoic Acid ◽  
Acid Methyl ◽  
Emulsion Polymers ◽  
Small Excess ◽  
Minimum Interference

Abstract Internal double bonds formed by 1,4-polymerization of diene monomers add perbenzoic acid more rapidly than do vinyl double bonds which are the products of the 1,2-type of addition. The extrapolation procedure proposed for determining internal double bond contents of diene polymers is based on this difference in addition rates. Oleic acid mixtures with 10-undeeylenie acid were prepared and analyzed with an accuracy of 1 per cent. However, the method is limited to systems containing 70 per cent or more internal double bonds. Minimum interference of side-chain oxidation by perbenzoic acid was attained by using a low temperature and a small excess of perbenzoic acid. Methyl-substituted emulsion polymers are characterized by high amounts of 1,4-addition. Polymerizations with alkali-metal catalysts result in products of high vinyl double-bond content. A slight preference for the 1,4-type of polymerization is favored in media of low pH. Natural rubbers are formed almost completely by 1,4-polymerization. Heat softening, modifier concentration, and extent of conversion do not influence the degree of 1,4-polymerization.

Mathematical Model of the Effective Properties of a Fiber Reinforced Composite with a Linearly Graded Transition Zone

2010 ◽  
Vol 38 (4) ◽  
pp. 286-307
Author(s):  
Carey F. Childers
Keyword(s):  
Mathematical Model ◽  
Transition Zone ◽  
Effective Properties ◽  
Local Stress ◽  
Stress And Strain ◽  
Fiber Reinforced ◽  
Strain Fields ◽  
Shear Moduli ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite

Abstract Tires are fabricated using single ply fiber reinforced composite materials, which consist of a set of aligned stiff fibers of steel material embedded in a softer matrix of rubber material. The main goal is to develop a mathematical model to determine the local stress and strain fields for this isotropic fiber and matrix separated by a linearly graded transition zone. This model will then yield expressions for the internal stress and strain fields surrounding a single fiber. The fields will be obtained when radial, axial, and shear loads are applied. The composite is then homogenized to determine its effective mechanical properties—elastic moduli, Poisson ratios, and shear moduli. The model allows for analysis of how composites interact in order to design composites which gain full advantage of their properties.

Connected-Tube MPP Model for Unsupervised 3D Fiber Detection

2020 ◽  
Vol 2020 (14) ◽  
pp. 305-1-305-6
Author(s):  
Tianyu Li ◽  
Camilo G. Aguilar ◽  
Ronald F. Agyei ◽  
Imad A. Hanhan ◽  
Michael D. Sangid ◽  
...  
Keyword(s):  
Composite Material ◽  
Point Process ◽  
Marked Point ◽  
Experimental Results ◽  
Marked Point Process ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Proposed Model ◽  
Cylinder Model ◽  
Reinforced Composite Material

In this paper, we extend our previous 2D connected-tube marked point process (MPP) model to a 3D connected-tube MPP model for fiber detection. In the 3D case, a tube is represented by a cylinder model with two spherical areas at its ends. The spherical area is used to define connection priors that encourage connection of tubes that belong to the same fiber. Since each long fiber can be fitted by a series of connected short tubes, the proposed model is capable of detecting curved long tubes. We present experimental results on fiber-reinforced composite material images to show the performance of our method.

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