Single Crystals of Chain-Folded Copolyterephthalamides

Manet, Sabine; Tibirna, Carmen Mihaela; Boivin, Julie; Delabroye, Christine; Brisson, Josée

doi:10.1021/ma052248k

Cited by 9 publications

(9 citation statements)

References 40 publications

(74 reference statements)

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“…These vary, on average, from 37 to 50%, but contrarily to the PPTA-based copolymers (13), no significant effect of chain length was found in this case. Crystallinity were also investigated using X-ray diffraction, with has two main assets: no thermal degradation, and the possibility of ascertaining which of the crystal forms was obtained.…”

Section: Characterization Of the Rigid-flexible Copolymersmentioning

confidence: 54%

“…The present work will focus on a variation of the rigid blocks size, the spacer in this case being a simple short alkyl chain. Our group has previously shown that incorporation of rigid, crystalline oligo(para-phenyleneterephthalamide) rigid blocks alternating with short flexible spacers led to copolymers which form a single phase and which retain a high crystallinity (12,13). It was also found that rigid block polydispersity resulted in a marked crystallinity decrease.…”

Section: Introductionmentioning

confidence: 99%

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Synthesis of Rigid-Flexible Polyetherketone–Based Copolymers

Benoit

Fürtös

Hudon

et al. 2013

Journal of Macromolecular Science, Part A

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Syntheses of symmetrical etherketone rigid blocks containing from four to ten aromatic rings were performed by a succession of Williamson synthesis steps, followed by deprotection by BBr 3 . Solubility decreased upon an increase in number of aromatic rings. Bis-(p-oxy-(p-hydroxyphenyl))benzophenone, a four-ring block, was soluble in the usual solvents (dichloromethane and chloroform), while 6 and 8-ring blocks were only soluble in dichloromethane to which trifluoroacetic acid was added. Rigid-flexible copolyetherketones with very short flexible segments were synthesized by reacting the 8-ring block with dibromo-terminated short alkane chains of 4 to 10 CH 2 units in the presence of sodium hydride. Molar masses were estimated by MALDI-TOF, which was also used to verify the incorporation of the flexible spacers in a regular way. Copolymers are of moderate molecular weights (M w values from 1240 to 2610 g mol −1 ), and of low polydispersity (from 1.02 to 1.17). Rigid blocks and rigid-flexible copolymers show high crystallinity and low solubility, in spite of the presence of the aliphatic spacers along the chain backbone, showing that incorporation of regularly spaced flexible segments does not decrease crystallization significantly. These flexible chains however decrease thermal stability of the copolymers.

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Section: Characterization Of the Rigid-flexible Copolymersmentioning

confidence: 54%

Section: Introductionmentioning

confidence: 99%

Synthesis of Rigid-Flexible Polyetherketone–Based Copolymers

Benoit

Fürtös

Hudon

et al. 2013

Journal of Macromolecular Science, Part A

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“…FTIR (cm -1 ): 2922 (δ a aliphatic (C-H)), 2851 (δ s aliphatic (C-H)), 1656 + 1640 (amide I), 1553 (amide II). 1 …”

Section: Synthesis Of 3ara-c10mentioning

confidence: 99%

“…FTIR attenuated total reflectance spectra (ATR) spectra of molecules and of mpI were also taken, using a resolution of 4 cm -1 , using the same spectrometer, using a Golden Gate sample holder and a DTGS detector in the 4000-530 cm -1 spectral domain. 1 H NMR spectra were recorded on a Bruker AC-300 apparatus functioning at 300 MHz, using tetramethylsilane (TMS) as an internal reference. The spectra consisted of 16 acquisitions and were analyzed using the SpinWorks version 1.3B software.…”

Section: Fourier Transform Infrared Spectroscopymentioning

confidence: 99%

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Effect of chain ends on the structure of aramid oligomers

Mehenni¹,

Guillou²,

Tessier³

et al. 2008

Can. J. Chem.

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Synthesis, X-ray diffraction, and Fourier transform infrared spectroscopy of aliphatic-aromatic aramid oligomers are reported with the aim of shedding light on the effect of end-chain substituent on the morphology and structure of poly(para-phenylene terephthalamide) or PPTA. Three types of X-ray powder diffraction patterns were observed: one similar to that of PPTA form I, one similar to that of PPTA form II, and an additional form never reported. Some compounds, differing by their internal distribution of amide-aromatic rings, adopt two different crystal structures, whereas compounds having the same internal amide-aromatic arrangements, but differing by the nature of the end-groups, can adopt the same crystal structure. This clearly shows that both factors influence the packing adopted by the chains. Single-crystal structures of two polymorphs of a nitro-terminated model compound were resolved; both forms incorporate dimethyl formamide, and both show completely different packing. Infrared amide I and II band positions of most studied compounds match those observed for PPTA forms I or II, indicating that they exhibit planar hydrogen bonded sheets of molecules.Résumé : La synthèse et des études de diffraction des rayons X, et de spectroscopie infrarouge à transformée de Fourier ont été effectués sur des oligomères aramides, dans le but de fournir des informations sur l'effet de substituants en bout de chaîne sur la morphologie et la structure du poly(para-phénylene téréphthalamide), ou PPTA. Trois types de clichés de diffraction de poudre ont été observés: un similaire à celui de la forme I du PPTA, un similaire à celui de la forme II, et une forme additionnelle jamais rapportée auparavant. Certains composés modèles qui diffèrent de par leur distribution interne de cycles aromatiques et de groupements amides adoptent des structures cristallines différentes, alors que certains composes modèles ayant le même arrangement interne de cycles aromatiques, adoptent la même structure cristalline. Ceci démontre clairement que ces deux facteurs influencent l'arrangement moléculaire adopté par les chaînes. Les structures cristallines de monocristaux de deux polymorphes d'un composé modèle ayant un substituant nitro en bout de chaîne ont été résolues, les deux incluent des molécules de diméthylformamide, et les deux adoptent des types d'empilement moléculaire complètement différents. En spectroscopie infrarouge, les positions des bandes amide I et II de la plupart des composes étudiés correspondent à celles observées pour les formes I et II du PPTA, indiquant que ces composés possèdent probablement des feuillets de molécules assemblées par liaison hydrogène.Mots-clés : aramide, structure cristalline, poly(para-phénylène téréphtalamide).

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Synthesis of Telechelic Poly(ether sulfone) Oligomers by Chain‐Growth Condensation Polymerization

Benhalima

Fürtös

Brisson

2013

Macro Chemistry & Physics

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The synthesis of telechelic poly(ether sulfone)s with methoxy end groups is reported. Molecular weights ranging from 1600 to 2800 g mol−1 and polydispersities of 1.1–1.2 are synthesized by chain‐growth condensation polymerization. The initiator is chosen by using semiempirical calculations and 19F NMR spectroscopy measurements. The polymers are characterized by NMR spectroscopy and matrix‐assisted laser desorption/ionization time of flight (MALDI‐TOF) mass spectrometry (MS), and are terminated by a methoxy group at one end and a fluorine at the other, and up to approximately 20% polymer of similar mass but slightly higher polydispersity, methoxy terminated at both ends, is present, along with less than 5% of polymer terminated at both ends by fluorine atoms. These do not need to be separated, and can be converted to methoxy‐ending telechelic blocks, yielding polyvalent, reactive rigid building blocks for copolymer synthesis.

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Single Crystals of Chain-Folded Copolyterephthalamides

Abstract: sciences et inge ´nierie des macromole ´cules, Faculte ´des sciences et de ge ´nie, UniVersite ´LaVal, Que ´bec, Que ´bec, Canada G1K 7P4

Cited by 9 publications

References 40 publications

Synthesis of Rigid-Flexible Polyetherketone–Based Copolymers

Synthesis of Rigid-Flexible Polyetherketone–Based Copolymers

Effect of chain ends on the structure of aramid oligomers

Synthesis of Telechelic Poly(ether sulfone) Oligomers by Chain‐Growth Condensation Polymerization

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