The role of nanoclay on surface roughness and characteristics of epoxy polysulfide nanocomposite

Abstract

Polysulfide polymers are known as sealants. Good adhesion and elastic properties are the significant features of sealants. The epoxy polysulfide resin due to end epoxy group in the chain of polysulfide polymer has the both properties of epoxy and polysulfide resins These dual properties, along with nanoparticles, can provide a variety of applications for its nanocomposites. It is common that epoxy resin is used for modifying polysulfide resin. In this research, epoxy polysulfide resin with dual properties for preparation of nanocomposites has been used. For this purpose, 1, 3 and 5 wt% nanoclay were dispersed in epoxy polysulfide matrix and each sample was coated on clean metallic plates. Then samples were evaluated by XRD, SEM, AFM, DMTA and adhesion tests. The XRD results showed that separation between the plates of nanoclay increased from 32 to 48 nm, and according to SEM results, the best dispersion was observed in the 3% nanoclay sample. The surface roughness in all samples increased and in the sample with 3% nanoclay average numerical absolute of height peak increased from 47 to 329 nm. The adhesion of the nanocomposite to the surface decreased in all samples and the highest decrease was observed in 3% nanoclay samples. The study of viscoelastic properties showed that with increasing nanoclay content to the control sample, the storage modulus decreased from 2180 to 1620 MPa. Also, the glass transition temperature and cross-link density has slightly decreased with increasing nanoclay.