PSI - Issue 5

L. ALEXANDRESCU et al. / Procedia Structural Integrity 5 (2017) 667–674 Laurentia Alexandrescu/ Structural Integrity Procedia 00 (2017) 000 – 000

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Figure 2. Brabender mixing diagram for nanocomposite with 2 % nanopowder of ZnO and 1,2 % TiO 2

In order to establish the curing times, the samples were rheologically tested using Monsanto Rheometer with oscillating disc. From the data it is observed that ZnO and TiO 2 nanoparticles do not influence the crosslinking time, diagrams are identical for the tests conducted, as demonstrated in figures 3. The compound was then compression-molded (using an electrically heated hydraulic press at 170°C under 200 MPa pressure) into a sheet of about 2 mm thick. The sheet was then cooled down to room temperature under same pressure. The specimens were die-cut from the compression molded sheet and used for testing after 24 hours of storage at room temperature.

Figure 3. Overlapping rheogram for samples N15-N18

Apparatus for physico-mechanical tests: Tensile tests of the samples were carried out according to SR ISO 37:2012 using a Schopper Tensile Testing machine 1445, at a constant crosshead speed of 500  5 mm/min. Hardness of the samples was measured by Shore “A” Durometer according to SR ISO 7619-1:2011. Attrition test is carried out with the roll abrader , in compliance with SR ISO 4649/2010. Melt flow index. Samples were tested using a Melt Flow Index device – Haake that displays values for the melt volume rate (MVR – cm 3 /10min) as well as melt flow rate (MFR- g/10min). Working temperature (chamber temperature up to 350°C), 2 heating areas, operating according to ISO 1133 standard. FT-IT spectroscopy was done using the FT-IR 4200 JASCO, Herschel series instrument, equipped with ATR having diamond crystal and sapphire head within the spectrometric range 2000-530 cm -1 .