Internal plasticization of chitosan with oligo(dl-lactic acid) branches

Ciulik, Claudio Batista; Bernardinelli, Oigres Daniel; Balogh, Débora Terezia; Azevêdo, Eduardo Ribeiro de; Akcelrud, Leni

doi:10.1016/j.polymer.2014.04.018

Cited by 6 publications

(11 citation statements)

References 31 publications

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“…Several lengths of the OLA segments were tested, and even the short ones failed to provide a miscible or compatible blend. On the other hand, when covalently bonded in a grafted configuration (chitosan-g-oligo DL-lactic acid) the materials presented interesting properties, which varied according to the ratio between the two macromolecular species involved [15]. Nevertheless, these properties did not followed the trend described so far for the networks.…”

Section: Mechanical Testmentioning

confidence: 71%

“…6a. The signals in the 50e110 ppm region are consistent with the chitosan/chitin backbone [27], except for the shoulder at 61.6 ppm (dashed green line), which is related to OeCeH carbons (C10) from OLA groups [15]. The signals at 16.6 ppm and 20.6 ppm are typical of CH 3 carbons from respectively, chitin (C8) and OLA (C11) units, while the signal at 30 ppm is relative to CH 2 carbons of succinyl units (C12 and C13), indicated by the red bracket.…”

Section: Structural Characterization Of Network By Ssnmrmentioning

confidence: 74%

“…The composition and transition temperatures of the networks are summarized in Table 2. For comparison purposes glass transition temperatures of pure OLA segments were determined previously [15] and ranged from À5 C to 30 C (molar masses from 1000 to 2500). Nevertheless no transitions in that range were detectable, in the DMA traces.…”

Section: Dynamic Mechanical Analysismentioning

confidence: 99%

“…In a previous work [15], the two materials used here to form networks were explored in two other combinations: blends and grafts. The blending resulted in very poor mechanical properties, did not afford useful materials in any proportion of the components, showing coarse phase separation as revealed by scanning microscopy.…”

Section: Mechanical Testmentioning

confidence: 99%

“…The potential application of the two systems as biomedical materials was also studied, showing promising results [14]. Aiming to get further improvement either in mechanical as in bio-properties, a new combination was explored: chitosan with poly(lactic acid) in the following macromolecular architectures: in the first, oligo(DL-lactic acid) segments, with systematic variation in the size and distance among each other were grafted onto the chitosan backbone [15]. In the second, which is the subject of the present contribution, networks of the two components were studied.…”

Section: Introductionmentioning

confidence: 99%

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Chitosan and oligo(dl-lactic acid) networks: Correlations between physical properties and macromolecular configuration

Ciulik

Bernardinelli

Azevêdo

et al. 2016

Polymer

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Aiming the obtainment of materials with useful properties for bio-applications, as thermal and mechanical (in particular flexibility), chitosan and low molecular weight poly(lactic acid) were chosen due to their biodegradability and biocompatibility in various bio-environments. Networks formed by oligo(DL-lactic acid) segments linked to the chitosan chains were prepared, in which the ratio between the components varied systematically. A thorough structural characterization was performed, including the degree of crosslinking and the size of the crosslinking blocks. The thermal and mechanical properties varied according the ratio between the components in a non-linear way, which was discussed in terms of the macromolecular architecture. The data were compared with previous results obtained for grafts with the same composition aiming to verify the effect of the macromolecular architecture on the macroscopic properties.

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Section: Mechanical Testmentioning

confidence: 71%

Section: Structural Characterization Of Network By Ssnmrmentioning

confidence: 74%

Section: Dynamic Mechanical Analysismentioning

confidence: 99%

Section: Mechanical Testmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Chitosan and oligo(dl-lactic acid) networks: Correlations between physical properties and macromolecular configuration

Ciulik

Bernardinelli

Azevêdo

et al. 2016

Polymer

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Facile Preparation and Properties of Crosslinked Copolyether Elastomers with 1,2,3‐Triazole and Urethane Subunit via Click Polymerization

Zhang¹,

Liu²,

Hu³

et al. 2019

ChemistryOpen

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An azide terminated ethylene oxide‐tetrahydrofuran copolymer with urethane segments (ATUPET) as a novel binder pre‐polymer, has been prepared through ethylene oxide‐tetrahydrofuran random copolymer (PET) end‐capping modification via one‐pot method. The structure characterization of the modifier has been analyzed by FTIR, 1 H NMR, 13 C NMR and GPC. In comparison with PET, ATUPET has a slightly higher viscosity because it has additional hydrogen bonding interaction generated by the urethane in ATUPET. Triazole cross‐linked elastomers based on ATUPET with various functional molar ratios were prepared using tripropargylamine as a curing agent and cross‐linker. Mechanical properties indicate that the modulus E and tensile strength σ b exhibit a parabolic dependence with the increase in R. At around the stoichiometric ratio, the modulus E and tensile strength σ b reach a maximum and the elongation at break exhibit an acceptable value at the same time. Swelling tests demonstrate that the apparent cross‐linking densities (N 0 ) have a maximum value at the stoichiometric ratio. Thermal analysis shows that the ATUPET prepolymer and its polytriazoles elastomers exhibit a satisfactory stability. The results demonstrated that ATUPET might be a promising polymeric binder for future propellant formulations especially in the field of isocyanate‐free curing technology.

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Utilization of olive tree branch cellulose in synthesis of hydroxypropyl carboxymethyl cellulose

Abdel-Halim

Alanazi

Al‐Deyab

2015

Carbohydrate Polymers

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Internal plasticization of chitosan with oligo(dl-lactic acid) branches

Cited by 6 publications

References 31 publications

Chitosan and oligo(dl-lactic acid) networks: Correlations between physical properties and macromolecular configuration

Chitosan and oligo(dl-lactic acid) networks: Correlations between physical properties and macromolecular configuration

Facile Preparation and Properties of Crosslinked Copolyether Elastomers with 1,2,3‐Triazole and Urethane Subunit via Click Polymerization

Utilization of olive tree branch cellulose in synthesis of hydroxypropyl carboxymethyl cellulose

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