چكيده به لاتين
Abstract:
Silica nanoparticles, due to their mechanical, environmental and other properties are now widely used in the composition of the polymers and nano-composites. In this research nano-silica was added to plastisol in the range of 0 to 1 percent and its effect on adhesion strength, some mechanical properties and melting and glass transition temperature is investigated. To determine the adhesion strength and mechanical properties the shear test and tensile test was performed respectively. Furthermore, for measuring the melting and glass transition temperatures the DSC test was used. Addition of nano-silica could improve adhesion strength form 323 kN/m2 to 1371 kN/m2 (up to 4 times). This improvement could be due to the high polarity of silica nanoparticles. Because of nanoparticles dispersion and Agglomeration the adhesion strength of plastisol increases non-linearly. Microscopic images also showed that the particle size of nanoparticles increase from 303 nm to 489 nm for samples containing 0.25% and 1% of nano-silica. Mechanical properties of coatings include stress and strain of tensile strength and fracture strain increase 6.5, 29.5 and 11 percent, respectively. The glass transition temperature for raw and containing 1 wt% of nano-silica samples are respectively -47.5 ˚C and -40 ˚C. Also the melting temperatures for these samples are obtained 169.5 ˚C and 176 ˚C, respectively. This increase could be due to interactions between nanoparticles and PVC. Replacing some of the DOP (Dioctyl Phthalate) with ESO (Epoxidized Soybean Oil) to 50 % in plastisols without silica caused improvement in adhesion strength of plastisol to the metal surface from 323 kPa to 369 kPa (to about 20 %) which is because of some degree of polarity in ESO. By replacing 50 % of the DOP with ESO in Plastisol containing silica nanoparticles the adhesion strength improved from 1150 kPa to 1213 kPa. Increasing the adhesion strength is diminished to less than 6% which is because of the high polarity of the blend. Increasing thickness of the coating applied to the surface from 0.06 mm to 0.93 mm, does not affect the adhesion strength but leads to Easier separation of the coating. This is because the peel force increases by increasing the coating thickness.
Keywords: Adhesion, PVC, Nano Silica, Nano Composite, Coating
