Improved mechanical dispersion or use of coupling agents? Advantages and disadvantages for the properties of fluoropolymer/ceramic composites. (10th October 2018)

• Record Type: Journal Article
• Authors: Dalle Vacche, Sara; Michaud, Véronique; Damjanovic, Dragan; Månson, Jan-Anders E.; Leterrier, Yves
• Is Part Of: Polymer. Volume 154(2018)
• Page Start: 8
• Page End: 16
• Publication Date: 2018-10-10
• Subjects: Polymer-matrix composite -- Thermomechanical properties -- Dielectric properties -- Coupling agents -- Interfacial chemistry; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2018.08.061
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: The aim of this work is to investigate the influence of interfacial chemistry on the properties of fluoropolymer composites, independent of effects derived from changes in morphology, in particular particle dispersion state. A comparative study of solvent cast composites of poly (vinylidene fluoride – trifluoroethylene) with barium titanate particles, at concentrations up to 60 vol%, was carried out using pristine hydrophilic particles, and particles hydrophobized with three organosilanes, bearing different functional groups (CH3, CH2 NH2 and CF3 ). For each filler concentration, composites with good particle dispersion and comparable amount of porosity with all types of particles were prepared and characterized. While pristine particles provided higher permittivity, all silanes decreased the dielectric losses due to Maxwell-Wagner-Sillars dispersion, although to different extents. Moreover, only the aminosilane provided better thermomechanical stability to the highly filled composites. These results provide useful insights into the advantages and disadvantages of the use of different approaches to improve the dispersion of hydrophilic particles in poly (vinylidene fluoride) copolymer based composites. Graphical abstract: Highlights: Good dispersion was obtained with pristine and surface modified BaTiO3 up to 60 vol%. Silanes bearing different end-groups were used to modify the BaTiO3 particles. Surface chemistry effects were highlighted, particle dispersion state being similar. Pristine particles led to higher permittivity up to 60 vol%. Aminosilane led to better thermomechanical stability and lower dielectric losses.