In this study, hybrid composites of polyurethane-acrylate (PUA) and silica nanoparticle were prepared by a radical method. For this aim, silica nanoparticles were chemically functionalized with 3-methacryloxypropyltrimethoxysilane. Polyurethane was synthesized and then modiﬁed with 2-hydroxyethyl methacrylate to yield PUA. Then, different amounts of modiﬁed-silica were used to prepare PUA composites by the addition of an ethylene glycol dimethacrylate crosslinker. Fourier-transform infrared spectroscopy conﬁrmed the successful functionalization of silica nanoparticles and the prepa-ration of PUA. Structural investigation of the functionalized-nanoparticles and also nanocomposites was carried out using X-ray diffraction and electron microscopy. According to the thermal gravimetric analysis results, char residue of HSiO₂ is 86.6%, which decreases to 81.3% in the case of MSiO₂ as a result of its modiﬁer degradation content of 5.3%. PUAS5 shows main decomposition temperatures of 396.5 and 454.9°C and also char content of 5.7% at 700°C. The high amount of MSiO₂ can also be resulted in higher degree of crosslinking and therefore higher thermal stabilities and char residue.
Volume 42 | Issue 6
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