Bejenariu, Anca Gabriela

Daugaard, Anders Egede

Skov, Anne Ladegaard

Online Research Database In Technology

                       General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.  • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal   If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.     Downloaded from orbit.dtu.dk on: Dec 20, 2017Unimodal and bimodal networks performance as dielectric electroactive polymers(DEAPs)Bejenariu, Anca Gabriela; Daugaard, Anders Egede; Skov, Anne LadegaardPublication date:2012Link back to DTU OrbitCitation (APA):Bejenariu, A. G., Daugaard, A. E., & Skov, A. L. (2012). Unimodal and bimodal networks performance asdielectric electroactive polymers (DEAPs). Abstract from 49th Nordic Polymer Days 2012, Copenhagen,Denmark.Unimodal and bimodal networks performance as dielectric electroactive polymers (DEAPs) Anca Gabriela Bejenariua, Anders Egede Daugaarda, Anne Ladegaard Skova aDTU, Department of Chemical and Biochemical Engineering, Kgs. Lyngby A polymer network is a three-dimensional entity formed by the interconnection of polymer chains and is sometimes referred to as an elastomer in the case of highly elastic material. Most model elastomers are prepared by an end-linking process using a crosslinker with a certain functionality f and a linear polymer with functional groups in both ends, and the resulting networks are so-called unimodal networks where unimodal refers to that there is one polymer only in the system. As an alternative to unimodal networks there are the bimodal networks where two polymers with significantly different molecular weights are mixed with one crosslinker1. Lately, dielectric electroactive polymers (DEAPs) which consist of an elastomer sandwiched between electrodes on both sides, have gained interest as materials for actuators, generators, and sensors. When a voltage is applied between the two electrodes an electrostatic field is created and the charges from the electrodes will attract each other, determining a decrease in the thickness of the film and an expansion in the area. Most of the actuators rely on commercial available silicone and acrylic soft elastomers which initially were not developed for DEAPs applications. Hence, optimization of the elastomeric material improvement should be possible to meet the requirements of DEAPs. The electro-mechanical properties of silicone networks can be improved by addition of fillers. In the present study the optimization of electromechanical properties of both unimodal and bimodal silicone based networks is achieved by addition of different types and loadings of fillers. Optical microscopy pictures of microfillers and nanoclays in silicone networks are presented in Figure 1. a)   b)  Figure 1. Optical microscopy pictures with a magnification of 400 are taken for a) ElastosilRT 625 networks loaded with microparticles of 6µm and b) silicone networks loaded with nanoclays (300x300x1 nm).    Using a hydrosilylation addition reaction at room temperature between vinyl-terminated polydimethyl siloxanes (PDMS) and a 4-functional crosslinker in presence of platinum catalyst, silicone networks are synthesized. Different molecular weights of PDMS, different mixing procedures and various numbers of reaction steps are used. Several types of fillers (nano- and microparticles, nanoclays) and varied loadings are used to improve the electromechanical properties of both unimodal and bimodal soft networks. Emphasis is made on the combination of the fillers to increase the dielectric strength and to maintain the high flexibility of the network. As industrial reference for the electromechanical properties, ElastosilRT 625 networks (Wacker Chemie) are used. Rheological and dielectric measurements are recorded and compared with the DEAPs requirements for actuators application. The microfillers will increase the Young’s modulus, while the nanoclays seem to be good candidates for enhancement of the dielectric permittivity of the networks. Finally, networks loaded with fillers with good electromechanical properties are synthesized and proposed for DEAPs applications. 1. Bejenariu, A. G.; Yu, L.; Skov, A. L., Low moduli elastomers with low viscous dissipation. Soft Matter 2012, DOI=10.1039/b803770c. 

Unimodal and bimodal networks performance as dielectric electroactive polymers (DEAPs)

http://orbit.dtu.dk/ws/files/7783811/Abstract_NPD_31May2012KBH_1_.pdf

Unimodal and bimodal networks performance as dielectric electroactive polymers (DEAPs)

Abstract

Similar works

Full text

Available Versions

Online Research Database In Technology