Polyimides from 2,5-bis[4-(4-aminophenoxy)benzoyl]furan and their thermal crosslinking reaction

Several polyimides were prepared via two-step polycondensation from novel 2,5-furandicarboxylic acid–based diamine, 2,5-bis[4-(4-aminophenoxy)benzoyl]furan, with commercial dianhydrides. The chemical structures of the monomers and polymers were characterized by FT-IR and NMR in detail, respectively. The polyimides exhibited high performances with 5 wt% weight loss temperatures of over 410 oC, glass transition temperatures of over 214 oC, and tensile strengths and Young’s moduli of up to 130 MPa and 3.2 GPa, respectively. The thermal crosslinking mechanism was studied by FT-IR, Raman spectroscopy, and model reaction analysis, which showed the Diels–Alder reaction between the furan group and diphenylethylene group was the main reaction. The crosslinked polyimide films showed improved solvent resistance, and thermal and mechanical properties.

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Low dielectric, nanoporous fluorinated polyimide films prepared from PCL-PI-PCL triblock copolymer using retro-Diels–Alder reaction

Journal of Colloid and Interface Science ◽

10.1016/j.jcis.2013.04.014 ◽

2013 ◽

Vol 404 ◽

pp. 36-41 ◽

Cited By ~ 20

Author(s):

Junping Ju ◽

Qihua Wang ◽

Tingmei Wang ◽

Chao Wang

Keyword(s):

Triblock Copolymer ◽

Alder Reaction ◽

Diels Alder ◽

Polyimide Films ◽

Low Dielectric ◽

Fluorinated Polyimide ◽

Diels Alder Reaction

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Synthesis of a polycaprolactone-based material with shape-memory and mendability

Science and Technology Development Journal ◽

10.32508/stdj.v19i3.564 ◽

2016 ◽

Vol 19 (3) ◽

pp. 90-98

Author(s):

Tri Minh Phan ◽

Thuy Thu Truong ◽

Thanh Dac Nguyen

Keyword(s):

Shape Memory ◽

Optical Microscopy ◽

1H Nmr ◽

Alder Reaction ◽

Diels Alder ◽

Diels Alder Reaction ◽

Furan Compound ◽

Ft Ir ◽

Mild Temperature ◽

Tga And Dsc

new thermoset has been prepared from a bismaleimidic terminated polycaprolactone polyester and a tris-furan compound acting as a crosslinker via the Diels-Alder reaction between the furan and maleimide functionalities. Owing to the reversibility of the Diels-Alder chemistry and the increased mobility of the crosslinked polyester chains, this material had the ability to mend scratches under mild temperature conditions. The synthesized precursors and resulting crosslinked material were characterized using 1H NMR, FT-IR, GPC, TGA and DSC methods. The scratch mendability of the material was investigated using optical microscopy.

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Recent progress in the synthesis of bioactive polycyclic natural products

Pure and Applied Chemistry ◽

10.1351/pac200779040651 ◽

2007 ◽

Vol 79 (4) ◽

pp. 651-665 ◽

Cited By ~ 22

Author(s):

Masaaki Miyashita

Keyword(s):

Chemical Synthesis ◽

Stereoselective Synthesis ◽

Leukemia Cell ◽

Alder Reaction ◽

Diels Alder ◽

Coupling Reactions ◽

Chemical Structures ◽

Ovariectomized Mice ◽

Diels Alder Reaction ◽

Zoanthamine Alkaloids

The zoanthamine alkaloids, a type of heptacyclic marine alkaloid isolated from colonial zoanthids of the genus Zoanthus sp., have distinctive biological and pharmacological properties as well as their unique chemical structures with stereochemical complexity. Namely, norzoanthamine can suppress the loss of bone weight and strength in ovariectomized mice and has been considered a promising candidate for an antiosteoporotic drug, whereas zoanthamine has exhibited potent inhibitory activity toward phorbol myristate-induced inflammation in addition to powerful analgesic effects. Recently, norzoanthamine derivatives were demonstrated to inhibit strongly the growth of P-388 murine leukemia cell lines, in addition to their potent antiplatelet activities on human platelet aggregation. These distinctive biological properties, combined with novel chemical structures, make this family of alkaloids extremely attractive targets for chemical synthesis. However, the chemical synthesis of the zoanthamine alkaloids has been impeded owing to their densely fuctionalized complex stereostructures. We report here the first and highly stereoselective total syntheses of norzoanthamine and zoanthamine, which involves stereoselective synthesis of the requisite triene for intramolecular Diels-Alder reaction via three-component coupling reactions, a key intramolecular Diels-Alder reaction, and subsequent crucial bis-aminoacetalization as the key steps.

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The Role of Iodine Catalyst in the Synthesis of 22-Carbon Tricarboxylic Acid and Its Ester: A Case Study

Catalysts ◽

10.3390/catal9120972 ◽

2019 ◽

Vol 9 (12) ◽

pp. 972

Author(s):

Liu ◽

Zhang ◽

Wang ◽

Zan ◽

Zhang

Keyword(s):

Energy Gap ◽

Tricarboxylic Acid ◽

Alder Reaction ◽

Diels Alder ◽

Proton Nuclear Magnetic Resonance ◽

Ionization Mass ◽

Double Bonds ◽

Chemical Structures ◽

Diels Alder Reaction

Here, 22-carbon tricarboxylic acid (C22TA) and its ester (C22TAE) were prepared via the Diels–Alder reaction of polyunsaturated fatty acids (PUFAs) and their esters (PUFAEs) as dienes with fumaric acid (FA) and dimethyl fumarate (DF) as dienophiles, respectively. The role of an iodine catalyst for the synthesis of C22TA and C22TAE in the Diels–Alder type reaction was investigated using a spectroscopic approach. The chemical structures of the products were characterized using proton nuclear magnetic resonance (1H-NMR) and electrospray ionization mass spectrometry (ESI-MS) analysis. Results showed that nonconjugated dienes can react with dienophiles through a Diels–Alder reaction with an iodine catalyst, and that iodine transformed the nonconjugated double bonds of dienes into conjugated double bonds via a radical process. DF was more favorable for the Diels–Alder reaction than FA. This was mainly because the dienophile DF contained an electron-withdrawing substituent, which reduced the highest and lowest occupied molecular orbital (HOMO–LUMO) energy gap and accelerated the Diels–Alder reaction. By transforming nonconjugated double bonds into conjugated double bonds, iodine as a Lewis acid increased the electron-withdrawing effect of the carbonyl group on the carbon–carbon double bond and reduced the energy difference between the HOMO of diene and the LUMO of dienophile, thus facilitating the Diels–Alder reaction.

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Pyrolysis of 1-methylcyclohexene and methylenecyclohexane

Australian Journal of Chemistry ◽

10.1071/ch9760599 ◽

1976 ◽

Vol 29 (3) ◽

pp. 599 ◽

Cited By ~ 5

Author(s):

JL Garnett ◽

WD Johnson ◽

JE Sherwood

Keyword(s):

Rate Constants ◽

Alder Reaction ◽

Diels Alder ◽

Reaction Pathways ◽

Main Reaction ◽

Confidence Limits ◽

Radical Chain ◽

First Order ◽

Diels Alder Reaction ◽

Ring Fission

At 495� the decomposition of both 1-methylcyclohexene and methylenecyclohexane is homogeneous and first order overall, the rate constants (with 90% confidence limits) being (6.01 � 0.40) x 10-4 and (6.53 � 0.23) x 10-4 s-1 respectively. Pressure is not a good measure of the rate of decomposition of either isomer. Toluene inhibits the decomposition of both olefins, although the effect is more marked for the exo-isomer. The two main reaction pathways for 1-methylcyclohexene are a reverse Diels-Alder reaction, giving 2-methylbuta-1,3-diene and ethene, and a radical chain dehydrogenation to give toluene and benzene. Methylenecyclohexane cannot react through a reverse Diels-Alder reaction and ring fission gives a mixture of C3 and lower hydrocarbons. Dehydrogenation to give benzene and toluene is also important. Isomerization is a much more favoured pathway for methylenecyclohexane as expected from the relative thermodynamic stabilities of the isomers.

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Synthesis of Norbornene Derivative Using Diels-Alder Reaction

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.421.136 ◽

2011 ◽

Vol 421 ◽

pp. 136-139 ◽

Cited By ~ 5

Author(s):

Jun Seong Park ◽

Hyun Chul Oh ◽

Yong Sung Park ◽

Je Wan Woo

Keyword(s):

1H Nmr ◽

Alder Reaction ◽

Dioctyl Phthalate ◽

Diels Alder ◽

Basic Properties ◽

Important Material ◽

Diels Alder Reaction ◽

Ft Ir ◽

Dicarboxylic Ester

Cyclopentadiene is an important material for making norbornene, and can synthesize norbornene dicarboxylic ester through the maleate and Diels-Alder reaction. Also, a structure similar to that of the representative PVC plasticizer dioctyl phthalate(DOP) was synthesized, so as to confirm the structure of compounds through 1H-NMR, FT-IR, Mass, and HPLC, and to compare the basic properties with those of DOP.

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Multifunctional Biodegradable Polymers with Room Temperature Self-Healing and Rewritable Shape Memory Properties via Diels-Alder Reaction

10.20944/preprints201809.0145.v1 ◽

2018 ◽

Author(s):

Shenyang Cai ◽

Zhe Qiang ◽

Chao Zeng ◽

Jie Ren

Keyword(s):

Shape Memory ◽

Room Temperature ◽

Crosslinking Density ◽

Alder Reaction ◽

Diels Alder ◽

Poly Lactic Acid ◽

Crosslinking Reaction ◽

Self Healing ◽

Diels Alder Reaction ◽

Shape Memory Properties

Here, we present a series of novel block copolymers (BCP) from bio-derived monomers, poly(lactic acid)-block-poly(2,5-furandimethylene succinate) (PLA-b-PFS), in which the furan groups from PFS block can be crosslinked with bis(maleimido) triethylene glycol (M2) through a Diels-Alder reaction. This dynamic crosslinking reaction leads to a network structure for enhancing the mechanical properties compared to their linear BCP analogous. Decreasing the crosslinking density leads to a decrease of glass transition temperature of BCPs and a transition from glassy to rubbery-like behavior at room temperature. This allows a wide tunablity of both elastic moduli and yields of the materials. For the lowest crosslinking density. the material exhibits an over 50% self-healing efficiency at room temperature after five days, attributed to the low Tg (15.2 C) from the introduction of PFS block, allowing sufficient chain mobility for structure re-organization. Moreover, with the appropriate selection of crosslinking density (PLA-b-PFS/M2 (6/1)), it also shows an excellent shape memory property with a high recovery rate of 96.3% and a fixity rate of 97.3%. The permanent shape can be rewriteable due to the reversibility of Diels-Alder reaction. With these advanced functionalities and ease in large-scale fabrication, the PLA-b-PFS/M2 shows great promises for self-healing coatings or films with shape memory properties in a wide variety of applications such as packaging materials

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Crystal structure of 5,7,12,14-tetrahydro-5,14:7,12-bis([1,2]benzeno)pentacene-6,13-dione

Acta Crystallographica Section E Crystallographic Communications ◽

10.1107/s2056989016017461 ◽

2016 ◽

Vol 72 (12) ◽

pp. 1734-1738 ◽

Cited By ~ 1

Author(s):

Mohammad Nozari ◽

Jerry P. Jasinski ◽

Manpreet Kaur ◽

Anthony W. Addison ◽

Ahmad Arabi Shamsabadi ◽

...

Keyword(s):

High Resolution Mass Spectrometry ◽

Alder Reaction ◽

Diels Alder ◽

Rotating Disc ◽

H Nmr ◽

Separation Membranes ◽

Gas Separation Membranes ◽

Diels Alder Reaction ◽

Ft Ir ◽

Polymers Of Intrinsic Microporosity

The lattice of 5,7,12,14-tetrahydro-5,14:7,12-bis([1,2]benzeno)pentacene-6,13-dione, C34H20O2, at 173 K has triclinic (P-1) symmetry and crystallizes with four independent half-molecules in the asymmetric unit. Each molecule is generated from a C17H10O substructure through an inversion center at the centroid of the central quinone ring, generating a wide H-shaped molecule, with a dihedral angle between the mean planes of the terminal benzene rings in each of the two symmetry-related pairs over the four molecules of 68.6 (1) (A), 65.5 (4) (B), 62.3 (9) (C), and 65.8 (8)° (D), an average of 65.6 (1)°. This compound has applications in gas-separation membranes constructed from polymers of intrinsic microporosity (PIM). The title compound is a product of a double Diels–Alder reaction between anthracene andp-benzoquinone followed by dehydrogenation. It has also been characterized by cyclic voltammetry and rotating disc electrode polarography, FT–IR, high resolution mass spectrometry, elemental analysis, and1H NMR.

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