Isothermal curing of an uncatalyzed dicyanate ester monomer: Kinetics and modeling

Georjon, Olivier; Galy, Jean; Pascault, Jean‐Pierre

doi:10.1002/app.1993.070490812

Cited by 83 publications

(53 citation statements)

References 19 publications

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“…The T g value for the pCOp resin is very similar to the value found in literature (264 vs 268°C 17 ) and on the order of those of resins from commercial dicyanates (267-292°C 29,30,36 ). Increase of the length of the monomers decreases the value of T g .…”

Section: Thermal Characterization Of the Resinssupporting

confidence: 77%

Synthesis and characterization of new dicyanate monomers. A way to obtain fully aromatic crosslinked poly(ether ketone)s

Marcos‐Fernández

Posadas

Rodrı́guez

et al. 1999

J. Polym. Sci. A Polym. Chem.

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Several aromatic mono‐ and dicyanate monomers bearing ether and ketone groups in the main chain have been synthesized through high‐yield reactions widely used in organic chemistry. FT‐IR and NMR were used to characterize these monomers and the intermediate products. The cyclotrimerization reaction was studied by DSC in monocyanate models, and the enthalpy of the reaction was determined. The value obtained was approximately 95 kJ/mol of cyanate irrespective of the substituent and symmetry of the substitution. For short dicyanates, cyclotrimerization did not reach completion, and for long dicyanates, the enthalpy of reaction could not be evaluated with accuracy. The resulting cured polycyanurates networks, due to the selectivity of the cyclotrimerization reaction, could be considered as true fully aromatic crosslinked poly(ether ketone)s with controlled structure. Tg values of the networks were above 180°C. The higher values were found for shorter dicyanates and for monomers with para substitution. The 1% and 5% weight loss values in nitrogen were above 310 and 380°C, respectively, with char yields in the range 50–60%. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3155–3168, 1999

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Section: Thermal Characterization Of the Resinssupporting

confidence: 77%

Synthesis and characterization of new dicyanate monomers. A way to obtain fully aromatic crosslinked poly(ether ketone)s

Marcos‐Fernández

Posadas

Rodrı́guez

et al. 1999

J. Polym. Sci. A Polym. Chem.

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“…Osei-Owusu et al 11,12 used the "restated" DiBenedetto equation to fit T g -␣ data of the BADC system, finding F x /F m ϭ 0.25 and E x /E m ϭ 0.63, irrespective of differences in the catalyst used. Georjon et al 18 utilized the PW equation to fit the T g -␣ data of the BADC system and obtained ϭ 0.23, which is lower than the DSCdetermined value of ⌬C pϱ /⌬C po . A liquid dicyanate ester, 4,4Ј-[1,3-phenylene-bis(1-methylethylidene)]bisphenol dicyanate (PBMBDC), cured with or without a catalyst were investigated in several occasions, 1,16,19 from which the obtained values of varied from 0.43 to 0.57 when the PW equation was applied.…”

Section: Comparison Between Experimental Data and Theoretical Expressmentioning

confidence: 99%

Glass-transition temperature: Conversion relationship in the polycyclotrimerization of 4,4?-thiodiphenylcyanate

Lin¹,

Hong

2000

J. Polym. Sci. B Polym. Phys.

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“…As a measure of internal consistency, values reported for the thermal (i.e. 'uncatalysed') polymerisation of AroCy B10 using DSC are typically 101.7 kJ/cyanate [25], 107.5 [26], 113.5 [27], 101.6 [28], 98.7 [29], suggesting that the values here are a little depressed.…”

Section: Thermal Analysis Of Dicyanate Monomersmentioning

confidence: 99%

Examination of the Thermal and Thermomechanical Behavior of Novel Cyanate Ester Homopolymers and Blends with Low Coefficients of Thermal Expansion

et al. 2009

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A new four-step synthetic method is presented and applied to the preparation of three novel dicyanate monomers that comprise aryl/alkylene ether backbones with high molecular flexibility in high purity. The multi-step route involves four individual high yielding steps (each greater than 70%), thus giving an overall reaction yields for all four steps between 42% and 50% depending on the length of the backbone. The products of all steps are characterised using Fourier transform infrared spectroscopy, 1 H nuclear magnetic resonance spectroscopy, elemental analysis and melting point determination. DSC and alysis of 'uncatalysed' samples (i.e. those polymerised thermally in absence of a specific catalyst) display relatively sharp melting endotherms ranging from 66ºC to 125ºC, depending on the length (and hence flexibility of the backbone). All monomers display broad polymerisation exotherms within close agreement (87 ± 2 kJ/mol. cyanate), although the polymerisations occur in different temperature regimes. When catalysed (aluminium(III) acetylacetonate/dodecylphenol), DSC reveals that the exothermic polymerisation peaks occur at significantly lower temperatures than the uncatalysed analogues and have much narrower profiles, but tend occur in a similar temperature regime (i.e. the peak maxima fall within 205 o C -216 o C).The recorded polymerisation enthalpies for the catalysed monomers are ca. 93 ± 9.9 kJ/mol.Assessment of the thermal stabilities of the cured polycyanurates using TGA shows that the polymers lose 5% of their masses by ca. 346-366 o C, comparable with the commercial dicyanate AroCy B10, despite the greater aliphatic character. DMTA analysis is performed on the homopolymer of the commercial dicyanate AroCy B10 to validate the method and the results obtained are consistent with published data. The T g values of the homopolymers of (4a), (4b) and (4c) are determined from the peak maxima of the loss tangent, tan δ and are found to be 221 o C (4a), 139 o C (4b), and 121 o C (4c) and fall in the expected order as the backbone chain length and hence flexibility is increased. The storage moduli at 25ºC for the binary blends are significantly lower than the respective homopolymers, but the reduction in E' over the temperature range 25ºC to 200ºC is significantly improved compared with AroCy B10. When combined with AroCy B10, binary blends showed a reduction in CTE of up to 12 ppm/°C while maintaining the same value of T g .

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Isothermal curing of an uncatalyzed dicyanate ester monomer: Kinetics and modeling

Cited by 83 publications

References 19 publications

Synthesis and characterization of new dicyanate monomers. A way to obtain fully aromatic crosslinked poly(ether ketone)s

Synthesis and characterization of new dicyanate monomers. A way to obtain fully aromatic crosslinked poly(ether ketone)s

Glass-transition temperature: Conversion relationship in the polycyclotrimerization of 4,4?-thiodiphenylcyanate

Examination of the Thermal and Thermomechanical Behavior of Novel Cyanate Ester Homopolymers and Blends with Low Coefficients of Thermal Expansion

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