Improving dielectric permittivity by incorporating PDMS-PEG block copolymer into PDMS network

Polydimethylsiloxane (PDMS) is well-known to cause hydrophobic surfaces due to their low surface energy as well as they possess low conductivity and extremely low glass transition temperature 1. On the other hand, polyethyleneglycol (PEG) behaves hydrophilic and is a highly conductive polymer.Combination of both polymers as a block copolymer depicts a possibility for substantial improvement of properties such as high permittivity and non-conductivity – if carefully designed 2. The objective of my research is to synthesize PDMS-PEG block copolymer assembling into different morphologies such as lamellae, cylinder, gyroid and spheres based on different volume fraction ratio of PDMS andPEG. The synthesis of PDMS-PEG block copolymer is based on hydrosilylation reaction occurring at 60 °C and dry condition with presence of platinum catalyst as shown in Fig. 13,4. Different volume fraction of PDMS and PEG introduces different properties in terms of contact angles, dielectric permittivity and rheological behaviour. All morphologies of PDMS-PEG block copolymer in this study exhibit high storage permittivity; at the same time the loss permittivity is even higher which implies that the synthesized PDMS-PEG block copolymers are conductive. By incorporating conductive PDMS-PEG block copolymer into commercial PDMS elastomer from Wacker Chemie,the storage permittivity is significantly enhanced by 38% with 20% of PDMS-PEG block copolymer incorporated in pure PDMS network as depicted in Fig. 2.