Thermochromic poly(L-lactic acid) based materials and their printability on different substrates

Ionic liquids (ILs) have been combined with different polymer matrixes to develop smart and functional materials. Due to their versatility, hybrid materials with specific tailor made properties can be obtained, including printable thermochromic materials, with a strong potential for sensing applications. In this context, the thermochromic IL bis(1-butyl-3-methylimidazolium) tetrachloronickelate ([Bmim]2[NiCl4]) was incorporated into a biopolymer derived matrix, poly(L-lactic acid) (PLLA) in distinct concentrations up to 40% wt. aiming to develop environmentally friendly screen-printable printable thermochromic materials. The addition of IL does not induce changes on the thermal properties of the material. On the other hand, the incorporation of the IL leads to the development of a porous structure in the films, a mechanical plasticizing effect in the polymer matrix, revealed by the decrease of the Young's Modulus from 1110 ± 66 MPa to 572 ± 41 MPa and a increase in the electrical conductivity from 2.89x10-14 S·cm−1 to 2.66x10-8 S·cm−1, for PLLA and the samples with 40 % wt. of IL, respectively. Finally, the thermochromic material was screen-printed on various substrates, including paper, polyethylene terephthalate (PET), textile and wood, opening the way for a wide range of applications.

Descrição

Portuguese Foundation for Science and Technology (FCT):, Portugal UID/FIS/04650/2020, UID/QUI/00686/2020, NORTE-01-0145-FEDER-000084. Spanish State Research Agency (AEI), Spain and European Regional Development Fund (ERFD): PID2019-106099RB-C43/AEI/10.13039/501100011033. Basque Government Industry Department, Spain, under the ELKARTEK program. This study forms part of the Advanced Materials program and was supported by MCIN, Spain with funding from European Union NextGenerationEU (PRTR-C17.I1) and by the Basque Government under the IKUR program. Publisher Copyright: © 2024 The Authors

Palavras-chave

Ionic liquids PLLA Screen-printing Smart materials Thermochromism General Chemistry Environmental Chemistry General Chemical Engineering Industrial and Manufacturing Engineering