Synthesis of multi-thiol functionalized polylactic acid, polyhydroxybutyrate and polycaprolactone

Belkhir, Kedafi; Shen, Hang; Chen, Jianding; Jegat, Corinne; Taha, Mohamed

doi:10.1016/j.eurpolymj.2015.02.025

Cited by 12 publications

(10 citation statements)

References 49 publications

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“…The dramatically increased viscosity of PLA-Q compared to the PLA-CH 3 one is attributed to the presence of the quaternary ammonium groups on the chain ends of PLA-Q, the same result is commonly found in the literature 49 and explained by the fact that ionic interactions occur between the pendant ions of the polymer 50,51 ; thus the melt viscosity of PLA-Q, even with a small mean molecular weight, is in the same order of magnitude as the one of high-molecular weight polyesters without ions in their structures; for example, at 150 C, the viscosity of PLA-Q (average molecular weight of 6.9 × 10 3 g.mol −1 ) is about 10 3 Pa.s, this value corresponds approximatively to the one of linear PLA with an average molecular weight of 1.3 × 10 5 g.mol −1 at the same temperature and within the same frequency range, 45 at 140 C, PLA-Q shows a viscosity which varies between 3 × 10 3 and 7 × 10 3 Pa.s, these values are higher than those of a linear polycaprolactone (another polyester) with an average molecular weight of 1.28 × 10 5 g.mol −1 in the same conditions. 52,53 Bagrodia et al 49 demonstrated that the effect of molecular weight of ion-containing polymers on their melt viscosity does not follow the same law as their neutral homologs, and that the viscosity of low-molecular-weight polymers is more influenced by the presence of the ions than the one of higher molecular weight ones.…”

Section: Resultsmentioning

confidence: 97%

“…The synthesis of this polymer and its characterizations were detailed in previous works. [45][46][47][48] PLA-Q mean molecular weight was 6900 g.mol −1 , each branch was made of a linear chain of PLA of about 1000 g.mol −1 , the three branches were linked to a glycerol node to make the starshaped design. Quaternary ammonium compound with chloride as counter ion was grafted on chain ends of the star-shaped PLA, with a ratio of 4 molecules per branch, to make quaternary ammonium end-functionalized structures, with glass transition and melt temperatures of, respectively, 49.5 and 154.9 C.…”

Section: Methodsmentioning

confidence: 99%

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Rheological study of quaternary ammonium‐containing star‐shaped polylactic acid

Belkhir

Majesté

Jegat

et al. 2019

J of Applied Polymer Sci

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Quaternary ammonium-containing star-shaped polylactic acid (PLA-Q) is analyzed in melt rheology and found to follow a clustering behavior. The viscosity of this polymer is largely higher than its analog, of the same structure, without ammonium ions. This difference is attributed to physical interactions taking place between the ammoniums and hindering the flow of the melt polymer. The frequency sweeps of the storage (G 0 ) and loss (G 00 ) modulus of the melt PLA-Q are achieved at different temperatures and different shearing times. The iso-temperature and iso-time superposition of the resulting curves were achieved using, respectively, a temperature and a time shift factors, this superposition allowed the determination of the flow activation energy; its value corresponds to an ionic process confirming the ionic interactions. When the two shift factors are used simultaneously, a unique master curve of both G 0 and G 00 is obtained; this curve follows the Rouse model indicating the presence of two types of ionic associations within the melt polymer: a large number of multiplets having small size and a small number of clusters of larger size.

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Section: Resultsmentioning

confidence: 97%

Section: Methodsmentioning

confidence: 99%

Rheological study of quaternary ammonium‐containing star‐shaped polylactic acid

Belkhir

Majesté

Jegat

et al. 2019

J of Applied Polymer Sci

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“…The durability of the typical PCL polymer varies between two and four years, which sometimes is not suitable for certain applications like tissue engineering where a shorter degradation time is required. To shorten the degradation of PCL, other biodegradable polymers are often incorporated or copolymerized with it [11,12].…”

Section: Introductionmentioning

confidence: 99%

Effect of Polymer Concentration, Rotational Speed, and Solvent Mixture on Fiber Formation Using Forcespinning®

Obregon

Agubra

Pokhrel

et al. 2016

Fibers

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Polycaprolactone (PCL) fibers were produced using Forcespinning ® (FS). The effects of PCL concentration, solvent mixture, and the spinneret rotational speed on fiber formation were evaluated. The concentration of the polymer in the solvents was a critical determinant of the solution viscosity. Lower PCL concentrations resulted in low solution viscosities with a correspondingly low fiber production rate with many beads. Bead-free fibers with high production rate and uniform fiber diameter distribution were obtained from the optimum PCL concentration (i.e., 12.5 wt%) with tetrahydrofuran (THF) as the solvent. The addition of N, N-dimethylformamide (DMF) to the THF solvent promoted the gradual formation of beads, split fibers, and generally affected the distribution of fiber diameters. The crystallinity of PCL fibers was also affected by the processing conditions, spinning speed, and solvent mixture.

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“…It was recently clearly demonstrated that in case of a competitive reaction of Thiol and amine with isocyanate, the amine reaction is predominant and no perceptible reaction of thiol with isocyanate was obtained …”

Section: Resultsmentioning

confidence: 99%

Polylactic acid bioconjugated with glutathione: Thermosensitive self‐healed networks

Djidi

Mignard

Taha

2016

J of Applied Polymer Sci

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Polylactic acid was bioconjugated with glutathione (GSH) in a solvent‐free one step process. Thermo‐reversible networks were first obtained as a consequence of the supramolecular interactions induced by GSH moieties. Then dynamic covalent reactions were added to the networks' synthesis process using dialcohol‐functionalized Diels−Alder (DA) adducts. The main properties of these networks were analyzed in relation with their structures and the proportions of supramolecular and DA reactions. The thermo‐mechanical properties of the obtained transparent materials and their healing efficiency were evaluated by dynamic mechanical spectroscopy and tensile analyses. Crosslinking/de‐crosslinking temperatures varied from 36 to 112°C. The obtained networks showed self‐healing ability without external stimuli. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43436.

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Synthesis of multi-thiol functionalized polylactic acid, polyhydroxybutyrate and polycaprolactone

Cited by 12 publications

References 49 publications

Rheological study of quaternary ammonium‐containing star‐shaped polylactic acid

Rheological study of quaternary ammonium‐containing star‐shaped polylactic acid

Effect of Polymer Concentration, Rotational Speed, and Solvent Mixture on Fiber Formation Using Forcespinning®

Polylactic acid bioconjugated with glutathione: Thermosensitive self‐healed networks

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