Articles producció científica> Química Analítica i Química Orgànica

Network structure dependence on unconstrained isothermal-recovery processes for shape-memory thiol-epoxy 'click' systems

  • Identification data

    Identifier: imarina:5129972
    Authors:
    Belmonte A., Fernández-Francos X., De la Flor S., Serra À.
    Abstract:
    The shape-memory response (SMR) of 'click' thiol-epoxy polymers produced using latent catalysts, with different network structure and thermo-mechanical properties, was tested on unconstrained shape-recovery processes under isothermal conditions. Experiments at several programming temperatures (Tprog) and isothermal-recovery temperatures (Tiso) were carried out, and the shape-memory stability was analyzed through various consecutive shape-memory cycles. The temperature profile during the isothermal-recovery experiments was monitored, and it showed that the shape-recovery process takes place while the sample is becoming thermally stable and before stable isothermal temperature conditions are eventually reached. The shape-recovery process takes place in two different stages regardless of Tiso: a slow initial stage until the process is triggered at a temperature strongly related with the beginning of network relaxation, followed by the typical exponential decay of the relaxation processes until completion at a temperature below or very close to Tg. The shape-recovery process is slower in materials with more densely crosslinked and hindered network structures. The shape-recovery time (tsr) is significantly reduced when the isothermal-recovery temperature Tiso increases from below to above Tg because the network relaxation dynamics accelerates. However, the temperature range from the beginning to the end of the recovery process is hardly affected by Tiso; at higher Tiso it is only slightly shifted to higher temperatures. These results suggest that the shape-recovery process can be controlled by changing the network structure and working at Tiso < Tg to maximize the effect of the structure and/or by increasing Tiso to minimize the effect but increasing the shaperecovery rate.
  • Others:

    Author, as appears in the article.: Belmonte A., Fernández-Francos X., De la Flor S., Serra À.
    Department: Enginyeria Mecànica Química Analítica i Química Orgànica
    URV's Author/s: De la Flor Lopez, Silvia / Fernández Francos, Xavier / Serra Albet, Maria Angels
    Keywords: Thiol-epoxy Thermosets Temperature Stress Shape-memory polymer Progress Polymer networks Kinetics Isothermal-recovery Click chemistry Behavior
    Abstract: The shape-memory response (SMR) of 'click' thiol-epoxy polymers produced using latent catalysts, with different network structure and thermo-mechanical properties, was tested on unconstrained shape-recovery processes under isothermal conditions. Experiments at several programming temperatures (Tprog) and isothermal-recovery temperatures (Tiso) were carried out, and the shape-memory stability was analyzed through various consecutive shape-memory cycles. The temperature profile during the isothermal-recovery experiments was monitored, and it showed that the shape-recovery process takes place while the sample is becoming thermally stable and before stable isothermal temperature conditions are eventually reached. The shape-recovery process takes place in two different stages regardless of Tiso: a slow initial stage until the process is triggered at a temperature strongly related with the beginning of network relaxation, followed by the typical exponential decay of the relaxation processes until completion at a temperature below or very close to Tg. The shape-recovery process is slower in materials with more densely crosslinked and hindered network structures. The shape-recovery time (tsr) is significantly reduced when the isothermal-recovery temperature Tiso increases from below to above Tg because the network relaxation dynamics accelerates. However, the temperature range from the beginning to the end of the recovery process is hardly affected by Tiso; at higher Tiso it is only slightly shifted to higher temperatures. These results suggest that the shape-recovery process can be controlled by changing the network structure and working at Tiso < Tg to maximize the effect of the structure and/or by increasing Tiso to minimize the effect but increasing the shaperecovery rate.
    Thematic Areas: Mechanics Mechanical engineering Materials science, characterization & testing Materials science (miscellaneous) Materials science (all) Materiais General materials science General chemical engineering Engenharias iii Chemical engineering (miscellaneous) Chemical engineering (all) Aerospace engineering
    ISSN: 13852000
    Author's mail: angels.serra@urv.cat xavier.fernandez@urv.cat silvia.delaflor@urv.cat
    Author identifier: 0000-0003-1387-0358 0000-0002-3492-2922 0000-0002-6851-1371
    Last page: 149
    Record's date: 2024-09-07
    Journal volume: 21
    Papper version: info:eu-repo/semantics/acceptedVersion
    Link to the original source: https://link.springer.com/article/10.1007/s11043-016-9322-z
    Licence document URL: https://repositori.urv.cat/ca/proteccio-de-dades/
    Papper original source: Mechanics Of Time-Dependent Materials. 21 (2): 133-149
    APA: Belmonte A., Fernández-Francos X., De la Flor S., Serra À. (2017). Network structure dependence on unconstrained isothermal-recovery processes for shape-memory thiol-epoxy 'click' systems. Mechanics Of Time-Dependent Materials, 21(2), 133-149. DOI: 10.1007/s11043-016-9322-z
    Article's DOI: 10.1007/s11043-016-9322-z
    Entity: Universitat Rovira i Virgili
    Journal publication year: 2017
    First page: 133
    Publication Type: Journal Publications
  • Keywords:

    Aerospace Engineering,Chemical Engineering (Miscellaneous),Materials Science (Miscellaneous),Materials Science, Characterization & Testing,Mechanical Engineering,Mechanics
    Thiol-epoxy
    Thermosets
    Temperature
    Stress
    Shape-memory polymer
    Progress
    Polymer networks
    Kinetics
    Isothermal-recovery
    Click chemistry
    Behavior
    Mechanics
    Mechanical engineering
    Materials science, characterization & testing
    Materials science (miscellaneous)
    Materials science (all)
    Materiais
    General materials science
    General chemical engineering
    Engenharias iii
    Chemical engineering (miscellaneous)
    Chemical engineering (all)
    Aerospace engineering
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