Author, as appears in the article.: Silvia De la Flor; Alberto Belmonte; Xavier Fernández-Francos; Àngels Serra
Department: Química Analítica i Química Orgànica Enginyeria Mecànica
URV's Author/s: DE LA FLOR LOPEZ, SILVIA; Alberto Belmonte; Xavier Fernández-Francos; Àngels Serra
Keywords: Dual-curing Rheological analysis Thiol-epoxy
Abstract: 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.
Research group: Grup d'Investigació en Enginyeria Computacional i Experimental
Thematic Areas: Enginyeria mecànica Ingeniería mecánica Mechanical engineering
licence for use: https://creativecommons.org/licenses/by/3.0/es/
ISSN: 0261-3069
Author identifier: 0000-0002-6851-1371; n/a; 0000-0002-3492-2922; 0000-0003-1387-0358
Record's date: 2016-11-02
Last page: 127
Journal volume: 113
Papper version: info:eu-repo/semantics/acceptedVersion
Licence document URL: https://repositori.urv.cat/ca/proteccio-de-dades/
Entity: Universitat Rovira i Virgili
Journal publication year: 2017
First page: 116
Publication Type: Article Artículo Article
Repositori URV