Author, as appears in the article.: Belmonte, Alberto; Fernandez-Francos, Xavier; Serra, Angels; De la Flor, Silvia
Department: Química Analítica i Química Orgànica Enginyeria Mecànica
URV's Author/s: De la Flor Lopez, Silvia / Fernández Francos, Xavier / Serra Albet, Maria Angels / Serra Masdeu, Anna Isabel Maria
Keywords: Thiol-epoxy Thermosets Thermo-mechanical analysis Temperature Rheological analysis Polymer Networks Michael addition Mechanical-properties Kinetics Functional materials Dual-curing Differential scanning calorimetry Click reaction Chemistry
Abstract: © 2016 Elsevier Ltd An extensive characterization of a sequential dual-curing system based on off-stoichiometric “thiol-epoxy” mixtures was carried out using thiol compounds of different functionality. The intermediate and final materials obtained after each curing stages at different thiol-epoxy ratios were studied by means of thermomechanical and rheological experiments. The storage and loss modulus and the loss factor tan δ were monitored during the curing process to analyse gelation and network structure build-up. The critical ratio for gelation was determined making use of the ideal Flory-Stockmayer theory and compared with experimental results. Intermediate materials obtained in the vicinity of the theoretical critical ratio did not have the mechanical consistency expected for partially crosslinked materials, did not retain their shape and even experienced undesired flow upon heating to activate the second curing reaction. The rheological results showed that the critical ratio is higher than the predicted value and that a softening during the second curing stage affects the shape-retention at this ratio. From the thermomechanical results, a wide range of intermediate and final materials with different properties and applicability can be obtained by properly choosing the thiol-epoxy ratio: from liquid-like to highly deformable intermediate materials and from moderately crosslinked (deformable) to highly crosslinked (brittle) final materials.
Thematic Areas: Química Mechanics of materials Mechanical engineering Materials science, multidisciplinary Materials science (miscellaneous) Materials science (all) Materiais Matemática / probabilidade e estatística Interdisciplinar Geociências General materials science Engenharias iv Engenharias iii Engenharias ii Engenharias i Ciências agrárias i Ciência de alimentos Ciência da computação Astronomia / física Arquitetura e urbanismo
licence for use: https://creativecommons.org/licenses/by/3.0/es/
ISSN: 18734197
Author's mail: angels.serra@urv.cat xavier.fernandez@urv.cat annaisabel.serra@urv.cat silvia.delaflor@urv.cat
Author identifier: 0000-0003-1387-0358 0000-0002-3492-2922 0000-0001-9353-7154 0000-0002-6851-1371
Record's date: 2024-11-02
Papper version: info:eu-repo/semantics/acceptedVersion
Link to the original source: https://www.sciencedirect.com/science/article/abs/pii/S0264127516313004
Licence document URL: https://repositori.urv.cat/ca/proteccio-de-dades/
Papper original source: Materials & Design. 113 116-127
APA: Belmonte, Alberto; Fernandez-Francos, Xavier; Serra, Angels; De la Flor, Silvia (2017). Phenomenological characterization of sequential dual-curing of off-stoichiometric “thiol-epoxy” systems: Towards applicability. Materials & Design, 113(), 116-127. DOI: 10.1016/j.matdes.2016.10.009
Article's DOI: 10.1016/j.matdes.2016.10.009
Entity: Universitat Rovira i Virgili
Journal publication year: 2017
Publication Type: Journal Publications