UV curable nanocomposites with tailored dielectric response. (20th May 2020)

• Record Type: Journal Article
• Authors: Mendes-Felipe, C.; Rodrigues-Marinho, T.; Vilas, José L.; Lanceros-Mendez, S.
• Is Part Of: Polymer. Volume 196(2020)
• Publication Date: 2020-05-20
• Subjects: Polymer composites -- UV curing -- Polyurethane acrylate photoresin -- Barium titanate -- Dielectric properties; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2020.122498
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: Photopolymerization or UV curing represents a fast and solvent-free technique to obtain polymer-based composites, being one of the main methods used in lithographic processes, surface coatings and the manufacture of integrated circuits. This work reports on the development of UV curable barium titanate/polyurethane acrylate (BaTiO3 /PUA) composites with varying ceramic contents in order to tailor the dielectric response of the material. A good dispersion of the ceramic particles within the polymer matrix is obtained, together with a thermal stability of the composites up to 160 °C. The inclusion of the BaTiO3 nanoparticles onto PUA photoresin slightly decrease the glass transition temperature of the organic matrix. The obtained white coloured films show mechanical flexibility with elongations at break up to 25%. The increase of BaTiO3 content leads to an increase of the dielectric constant up to 25 for sample with 65 wt% content. The size of the BaTiO3 nanoparticles proved not to be a key factor on determining the dielectric constant value of the composite for filler sizes up to 100 nm. Theoretical studies demonstrate that the model that better predict the behaviour of the BaTiO3 /PUA composites is the Tinga model, giving insights on the physical phenomena determining the dielectric response of the materials. Thus, high dielectric UV curable composites are obtained suitable for microelectronics applications. Graphical abstract: Image 1 Highlights: PUA is a good UV curable matrix to obtain composites with BaTiO3 contents up to 65 wt%. Thermal stability up to 160 °C and mechanical flexibility is achieved independently of the BaTiO3 content or size. The dielectric constant can be tailored being as high as 25 for maximum BaTiO3 content. Tinga model suitably described the dielectric behavior as a function of filler concentration.