New crosslinking end caps for polyquinoline prepolymers: synthesis, processing, and thermal properties

Upshaw, Thomas A.; Stille, J. K.; Droske, John P.

doi:10.1021/ma00009a001

Cited by 23 publications

(13 citation statements)

References 4 publications

(9 reference statements)

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“…Reaction of a vinylzinc with 6 in the presence of a Pd 0 catalyst proceeded readily to give the vinyl pleiadene derivative in 98 % yield (Scheme 4). Substitution of the bromo pleiadene derivative [2] for the iodo Scheme 4. Synthesis of 5.…”

Section: Resultsmentioning

confidence: 99%

“…The exceptional physical properties of diamond (hardness, high refractive index, and high thermal conductivity) can ultimately be ascribed to the compact, strong, directional carbon ± carbon single covalent bonds that make up this three-dimensional extended solid. [1] Many approaches have been utilized to prepare high-strength organic materials by thermal crosslinking [2] and hypercross-linking. [3±6] The elusive hydrocarbon pleiadene 1 [7] is of interest from a theoretical [8±12] and, more recently, from a practical viewpoint as a chain-extending end cap for flexible quinoline oligomers.…”

Section: Introductionmentioning

confidence: 99%

“…[3±6] The elusive hydrocarbon pleiadene 1 [7] is of interest from a theoretical [8±12] and, more recently, from a practical viewpoint as a chain-extending end cap for flexible quinoline oligomers. [2] Attempts to isolate it at room temperature have always led to the formation of the anti dimer 2, [9,11,12,13] as characterized by 1 H NMR spectroscopy. Though the pleiadene dimer can be generated from either 7,12-dibromo-or 7,12-dihydropleiadene-7,12-sulfone, [13] the strained benzocyclobutene 3 (6b-10b-dihydrobenzo[j]cyclobut[a]acenaphthy-lene) [9,11] is the most efficient precursor for the thermal or low-temperature photochemical generation of 1 as a shortlived intermediate.…”

Section: Introductionmentioning

confidence: 99%

“…Though the pleiadene dimer can be generated from either 7,12-dibromo-or 7,12-dihydropleiadene-7,12-sulfone, [13] the strained benzocyclobutene 3 (6b-10b-dihydrobenzo[j]cyclobut[a]acenaphthy-lene) [9,11] is the most efficient precursor for the thermal or low-temperature photochemical generation of 1 as a shortlived intermediate. [10,12] Though pleiadene dimerization has been briefly described for the chain extension of macromolecules, [2] there are no reports of its utilization as a polymerization functional group. This pleiadene polymerization/cross-linking process possesses the two distinct advantages usually associated with cycloadditive polymerizations such as the Diels ± Alder polymerization: 1) it is achieved without the evolution of volatile byproducts, allowing easier processing of the polymer into the final molded product in a single step and, 2) it does not introduce any weak links into the polymer in the form of heteroatoms or free radical-, anion-, or cation-stabilizing groups.…”

Section: Introductionmentioning

confidence: 99%

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Pleiadene Dimerization and Its Application to the Construction of Novel Carbon Networks

1999

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The synthesis of the anti-and syn-pleiadene dimers 2 has been carried out in solution and in the solid state from (6b-10b-dihydrobenzo[j]cyclobut[a]acenaphthylene) (3). The structures of the anti-and syn-2 dimers were determined by X-ray crystallography and by NMR spectroscopy and mass spectrometry. An exhaustive thermal analysis of the two dimers has been carried out, establishing that the equilibrium for their interconversion occurs via pleiadene as an intermediate species.Vinyl-6b-10b-dihydrobenzo[j]cyclobut[a]acenaphthylene (5) has been synthesized and used as a pre-monomer for the preparation of poly(pleiadene) dimer through either thermal or photochemical polymerization.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Pleiadene Dimerization and Its Application to the Construction of Novel Carbon Networks

1999

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“…Considerable attention has been paid toward dual functional polymers such as liquid crystalline and photocrosslinkable polymers (LC‐PCPs), ascribed to the presence of mesogen and photoreactive groups in the polymer back bone [1]. The photocrosslinkability in the polymer is attributed to the greater π‐electron density of photoreactive group [2].…”

Section: Introductionmentioning

confidence: 99%

Liquid crystalline and photocrosslinkable poly(4,4′‐stilbeneoxy) alkylarylphosphates

Ravikrishnan

Sudhakara

Kannan

2011

Polymer Engineering & Sci

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Three series of liquid crystalline and photocrosslinkable poly(4,4 0 -stilbeneoxy) alkylarylphosphates were synthesized from various 4,4 0 -bis(m-hydroxyalkyloxy)stilbenes (m ¼ 2, 4, 6, 8, 10) and arylphosphorodichloridates in chloroform by solution polycondensation method. Polarized optical microscope (POM) and differential scanning calorimetry (DSC) observations revealed that polymers containing less than four methylene spacer groups did not exhibit liquid crystalline (LC) texture, possibly due to smaller microdomain and restricted movement of the mesogen. In contrast, polymers containing more than four methylene spacer group established LC texture, which has been attributed to the larger monodomain and free movement of mesogens. Thermogravimetric analysis (TGA) data indicated that thermal stability and char yield decreased with increasing flexible methylene spacer groups, increased significantly for biphenyloxy and 1naphthyloxy containing polymers than that of phenyloxy containing polymers ascribed to increasing aromaticity, size, and number of aromatic rings. Photocrosslinking of stilbene containing polymers has been shown to proceed via 2p-2p cycloaddition reaction by Ultra-violet (UV) and fluorescence. The rate photocrosslinking has been found to increase with increasing number of methylene group in the main chain. The aromaticity of the side chain also increases the rate of crosslinking. POLYM. ENG. SCI., 52:598-606, 2012. ª 2011 Society of Plastics Engineers EXPERIMENTAL MaterialsBromoacetaldehyde diethylacetal, 2-chloroethanol, 4-chloro-1-butanol, 1,6-hexane diol, 1,8-octane diol,

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Efficient Modular Synthesis of Isomeric Mono‐ and Bispyridyl[2.2]paracyclophanes by Palladium‐Catalyzed Cross‐ Coupling Reactions

et al. 2016

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Pyridyl-substituted [2.2]paracyclophanes build am ultifunctional structural motif that is useful in material chemistry,c atalysis and for luminescent structures.N onetheless,t here is still al ack of general methodsf or the synthesiso ft hese structures tolerating easily accessiblebromides as well as different isomeric pyridyl groups.H ence the coupling of functionalized [2.2]paracyclophanes with various substituted andf unctionalized pyridyl derivatives was ach-ieved using Stille,S uzuki andK umada coupling conditions.H ereby the Stille coupling of a [2.2]paracyclophane is presenteda saversatile reaction for the formation of heteromeric [2.2]paracyclophane-containing biaryl structures.

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New crosslinking end caps for polyquinoline prepolymers: synthesis, processing, and thermal properties

Cited by 23 publications

References 4 publications

Pleiadene Dimerization and Its Application to the Construction of Novel Carbon Networks

Pleiadene Dimerization and Its Application to the Construction of Novel Carbon Networks

Liquid crystalline and photocrosslinkable poly(4,4′‐stilbeneoxy) alkylarylphosphates

Efficient Modular Synthesis of Isomeric Mono‐ and Bispyridyl[2.2]paracyclophanes by Palladium‐Catalyzed Cross‐ Coupling Reactions

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