Order in amorphous di‐<i>n</i>‐alkyl itaconate polymers, copolymers, and blends

Arrighi, Valeria; Holmes, Paul F.; McEwen, I.J.; Qian, Hu-Jun; Terrill, Nicholas J.

doi:10.1002/polb.20265

Cited by 5 publications

(4 citation statements)

References 29 publications

(47 reference statements)

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“…This suggests that the fractional free volume is redistributing over time to increase the amount of microvoids with the larger d-spacing around 6.7 Å compared to the amount of voids with smaller d-spacing of 5.3 Å. [49,52] This change supports the idea of possible free volume interconnectivity and is in alliance with the increase of permeability for both the aging treatment and the thermal treatment. The similar "aged" and "300 °C" spectra also supports that thermal treatment above the Tg can facilitate chain movement in reaching the packing conformation that is likely eventually achieved through the aging process.…”

Section: Physical Aging Behaviormentioning

confidence: 63%

Analysis of governing factors controlling gas transport through fresh and aged triptycene-based polyimide films

Weidman

Luo

Doherty

et al. 2017

Journal of Membrane Science

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The fundamental gas transport properties and physical aging behavior of a series of triptycene-based polyimides with various substitution groups were investigated. Wide-angle xray diffraction revealed that the 6FDA-1,4-triptycene polyimides exhibit two chain packing domains with d-spacing values of ~6.7 Å and ~5.3 Å, corresponding to triptycene-induced chain packing disruption and chain segments lacking the triptycene moiety, respectively. Positron annihilation lifetime spectroscopy (PALS) showed a bimodal distribution of microcavity size made up of triptycene cleft cavities that are ~3 Å diameter and larger interchain cavities with an average diameter of ~7 Å. Additionally, PALS confirmed 6FDA-1,4-trip_CH3 has the lowest fractional free volume, primarily due to smaller contributions from the interchain cavities, and 6FDA-1,4-trip_CF3 has the largest fractional free volume. It was also found that the addition of substituent groups had a unique and positive effect on the aging properties over nine months, in which the addition of CH3 and CF3 groups led to permeability increases of ~20% and ~40%, respectively. This is caused by the combination of the lowered driving force for physical aging, the substituent groups sterically hindering tighter packing with time, and the interconnectivity and/or unblocking of free volume over time through small-scale, local chain motion.

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Section: Physical Aging Behaviormentioning

confidence: 63%

Analysis of governing factors controlling gas transport through fresh and aged triptycene-based polyimide films

Weidman

Luo

Doherty

et al. 2017

Journal of Membrane Science

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“…Given that conditions for obtaining higher loadings of DBI are accessible, it would be possible now to tune the desired glass transition temperature (Tg) of the copolymers, which was measured using differential scanning calorimetry (DSC). The variation in Tg with composition is bracketed by the Tgs of the homopolymers (Tg,PS are 100 °C [64] while the Tg,PDBI has been reported to vary between 5-17 °C [22,30,65,66]). Figure 10 shows the Tg of the various statistical copolymers as function of final copolymer composition as well as the Fox equation prediction, which is given in Equation (7) where wDBI and wS are the weight fractions of DBI and S and Tg,PDBI and Tg,PS are the experimental Tgs of PDBI and PS homopolymers.…”

Section: Resultsmentioning

confidence: 99%

Nitroxide-Mediated Copolymerization of Itaconate Esters with Styrene

et al. 2019

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Replacing petro-based materials with renewably sourced ones has clearly been applied to polymers, such as those derived from itaconic acid (IA) and its derivatives. Di-n-butyl itaconate (DBI) was (co)polymerized via nitroxide mediated polymerization (NMP) to impart elastomeric (rubber) properties. Homopolymerization of DBI by NMP was not possible, due to a stable adduct being formed. However, DBI/styrene (S) copolymerization by NMP at various initial molar feed compositions fDBI,0 was polymerizable at different reaction temperatures (70–110 °C) in 1,4 dioxane solution. DBI/S copolymerizations largely obeyed first order kinetics for initial DBI compositions of 10% to 80%. Number-average molecular weight (Mn) versus conversion for various DBI/S copolymerizations however showed significant deviations from the theoretical Mn as a result of chain transfer reactions (that are more likely to occur at high temperatures) and/or the poor reactivity of DBI via an NMP mechanism. In order to suppress possible intramolecular chain transfer reactions, the copolymerization was performed at 70 °C and for a longer time (72 h) with fDBI,0 = 50%–80%, and some slight improvements regarding the dispersity (Ð = 1.3–1.5), chain activity and conversion (~50%) were observed for the less DBI-rich compositions. The statistical copolymers produced showed a depression in Tg relative to poly(styrene) homopolymer, indicating the effect of DBI incorporation.

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“…At n ≥ 12, the PDAIs crystallize. 31 T g L presents a second major relaxation and this phenomenon has been ascribed to independent motions of the long side chains, as confirmed by DSC, 30,31 dynamic mechanical analysis, 31 X-ray diffraction, 32 dielectric spectroscopy, 11,33 solution NMR, 34 and molecular simulations. 34 Therefore, dialkyl itaconates are versatile precursors to tune side chain structures and properties of the relevant polymers.…”

Section: ■ Introductionmentioning

confidence: 71%

“…At n ≥ 12, the PDAIs crystallize , dynamic mechanical analysis, X-ray diffraction, dielectric spectroscopy, , solution NMR, and molecular simulations . Therefore, dialkyl itaconates are versatile precursors to tune side chain structures and properties of the relevant polymers.…”

Section: Introductionmentioning

confidence: 99%

Pendant Chain Effect on the Synthesis, Characterization, and Structure–Property Relations of Poly(di-n-alkyl itaconate-co-isoprene) Biobased Elastomers

Lei

Russell

et al. 2017

ACS Sustainable Chem. Eng.

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A series of biobased elastomers, poly(di-n-alkyl itaconateco-isoprene)s (PDAIIs), were prepared by using itaconic acid as a renewable starting material. It is revealed that pendent chain profoundly affected the structure and properties of PDAIIs. The molecular structures of the PDAIIs were analyzed by 1 H NMR and FTIR. Dialkyl itaconate to isoprene reactivity ratios measured by Kelen−Tudos method demonstrated that PDAIIs with short side chains tended to alternate copolymerized and the long side chain ones tented to gradient copolymerized. Glass transition temperature, dielectric properties, and thermal stability of the PDAIIs were studied and these properties were tunable by varying the side chain length. Tensile tests revealed that crosslinked PDAIIs are elastic with a high elongation at break. With renewable resources and the side chain adjustability, PDAII elastomers potentially have a positive economic and ecological impact.

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Order in amorphous di‐n‐alkyl itaconate polymers, copolymers, and blends

Cited by 5 publications

References 29 publications

Analysis of governing factors controlling gas transport through fresh and aged triptycene-based polyimide films

Analysis of governing factors controlling gas transport through fresh and aged triptycene-based polyimide films

Nitroxide-Mediated Copolymerization of Itaconate Esters with Styrene

Pendant Chain Effect on the Synthesis, Characterization, and Structure–Property Relations of Poly(di-n-alkyl itaconate-co-isoprene) Biobased Elastomers

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