Ethylene Propylene Diene Monomer (EPDM) Rubber based Nanocomposites for Application in Corrosive and Radiation Environments
Elastomeric components used in various nuclear applications have to withstand aggressive environments such as chemicals, corrosion and radiation. This project aims to develop an elastomer-based polymer hybrid nanocomposite [PNC] for such applications. Specific area targeted : EPDM based compounds are employed as the poylmeric materials for master-slave manipulators as booting materials, as gaskets or O rings in the equipment used in highly intense radioactive environments. EPDM possesses better general physical properties such as high heat resistance, ozone, cold temperature, radiation and moisture resistances. But it does not have resistance to environments that have long chain hydrocarbons. This drawback can be overcome by blending of EPDM with another polymer to enhance the desired properties and processing characteristics. The drawback of one polymer can be overcome by the benefits of the other polymer. Addition of compatibilizing agents reduces the interfacial tension between the two phases and aids in developing network structure in the phases and the interphase.
Halobutyl rubbers have low gas and moisture permeability, good weathering resistance, high thermal stability and solvent resistance. Hence blends of halobutyl rubber with EPDM would be attractive in applications that require a combination of radiation and solvent resistance. Several studies have shown that the incorporation of nanosized fillers remarkably improves the solvent resistance of polymers. Incorporation of nanoclay in elastomers like nitrile rubber, EPDM etc. have resulted in tremendous enhancement in solvent resistance as the nanoparticles introduce a tortuous path for the permeation of solvent through the polymer. The radiation resistance of polymers has been shown to improve with the incorporation of nano sized particles in the matrix. In multicomponent systems like elastomer blends, nanoparticles not only reinforce the polymer phases, but also can promote compatibilized structures of the phases.
The following aspects are envisaged for detailed investigation.
- Development of polymer hybrid nanocomposites [PNC] based on ethylene propylene rubbers [EPDM] – halobutyl rubber blends. The micro / nanofillers are incorporated into the polymer using different methods [melt or solution blending].
- Characterization of PNCs for various properties – Morphology [XRD, SEM, TEM, AFM studies], Mechanical, Viscoelastic and Thermal properties and ageing behavior in corrosive and radiation environment etc.
- Resistance to leaching by chemicals such as nitric acid or NOx vapour, tributyl phosphate and paraffin hydrocarbons (C10-C14).
- Study and model the properties of PNCs with respect to the filler content, additives levels and blend composition.
- Optimization of properties of the PNCs using DoE
- Product evaluation using a suitable recipe based on the studies.