Author, as appears in the article.: Gamardella, Francesco; Serra, Angels; Ramis, Xavier; De la Flor, Silvia;

Department: Enginyeria Mecànica

URV's Author/s: De la Flor Lopez, Silvia / Gamardella, Francesco / Serra Albet, Maria Angels

Keywords: Thiol Thermosets Single cantilever Shape-memory Recovery Polyurethane Polymers Poly(thiourethane) Latency Isocyanate click reaction Chemistry Actuator

Abstract: In this work, a new family of poly(thiourethane) shape memory thermosetting actuators was developed and characterized. These materials can be easily prepared from mixtures of two different aliphatic diisocyanates and a trithiol in the presence of a latent catalyst, allowing an easy manipulation of the formulation. Rheological studies of the curing process confirm the latent character of the formulations. The glass transition temperatures and the mechanical properties can be modified by varying the proportion of diisocyanates (hexamethylene diisocyanate, HDI, and isophorone diisocyanate, IPDI) with stoichiometric amounts of trimethylolpropane tris(3-mercaptopropionate). The shape-memory behavior was deeply investigated under three different conditions: unconstrained, partially constrained, and fully constrained. Tests were performed in single cantilever bending mode to simulate conditions closer to real complex mechanics of thermomechanical actuators under flexural performances. The complex recovery process in single cantilever bending mode was compared with that obtained using tensile mode. The results evidenced that the amount of recovery force in fully constrained conditions, or energy released during the recovery process in partially constrained, can be modulated by simply changing the proportion of both diisocyanates. A simple model based on Timoshenko beam theory was used for the prediction of the amount of work performed. The reported results are an important guideline to design shape-memory materials based on poly(thiourethane) networks, establishing criteria for the choice of the material depending on the expected application.

Thematic Areas: Polymers and plastics Polymer science Odontología General chemistry Farmacia Engenharias ii Ciências biológicas ii Chemistry (miscellaneous) Chemistry (all) Biotecnología Astronomia / física

licence for use: https://creativecommons.org/licenses/by/3.0/es/

Author's mail: silvia.delaflor@urv.cat angels.serra@urv.cat

Author identifier: 0000-0002-6851-1371 0000-0003-1387-0358

Record's date: 2023-02-19

Journal volume: 13

Papper version: info:eu-repo/semantics/publishedVersion

Link to the original source: https://www.mdpi.com/2073-4360/13/10/1571

Licence document URL: http://repositori.urv.cat/ca/proteccio-de-dades/

Papper original source: Polymers. 13 (10):

APA: Gamardella, Francesco; Serra, Angels; Ramis, Xavier; De la Flor, Silvia; (2021). Actuator Behaviour of Tailored Poly(thiourethane) Shape Memory Thermosets. Polymers, 13(10), -. DOI: 10.3390/polym13101571

Article's DOI: 10.3390/polym13101571

Entity: Universitat Rovira i Virgili

Journal publication year: 2021

Publication Type: Journal Publications