20.500.12556/RUL-143845 Characterisation of melamine formaldehyde microspheres synthesised with prolonged microencapsulated reaction time The aim of the research was to identify the influence of different microencapsulated reaction time on the morphology, size, infrared spectral, thermal and micromechanical properties of melamine formaldehyde microspheres, synthesised with modified in situ polymerisation. Microspheres are microencapsulated particles with a blurred boundary of the core and shell due to their same composition. The synthesis of microspheres was paused after 1, 3, 9 and 15 h, and stopped after 23 h. The scanning electron microscopy and granulometric analysis were used to study the morphology and size of microspheres. Regardless of the reaction time, the produced microspheres were spherical in shape and with a rough surface. The average size of microspheres was almost identical (0.709–0.790 µm), while the volume size distribution curve of the particles became narrower with prolonged reaction time. The curing mechanism of melamine formaldehyde resin was studied using the Fourier-transform infrared spectroscopy and thermal analysis, and nano-indentation identification. The results revealed a slightly more crosslinked structure: with minimal (neglected) increased thermal weight loss (only up to 0.5%) and minor increased Young’s modulus (up to 2.3%). Using a nano-indenter, the hardness of synthesised particles improved by up to 14.8% after 23 h reaction time. characterisation curing melamine formaldehyde resin microsphere reaction time karakterizacija zamreževanje melamin formaldehidna smola mikrosfere reakcijski čas true false true Angleški jezik Slovenski jezik Članek v reviji 2023-01-13 16:43:00 2023-01-13 16:43:01 2023-01-15 04:01:32 0000-00-00 00:00:00 2022 0 0 Str. 288–297 iss. 4 Vol. 42 7 Feb. 2022 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 677 2191-0340 10.1515/polyeng-2021-0289 97846019 10.1515_polyeng-2021-0289_(2).pdf 10.1515_polyeng-2021-0289_(2).pdf 1 50A9FA17A5DFF1B09ABDE194D5132CE9 ceb6807ab91523696446dd5ed446b64313700701614c5fd4e8c6adb60b7aeec2 f931fc7e-9358-11ed-9c94-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=165863 https://www.degruyter.com/document/doi/10.1515/polyeng-2021-0289/html 1 ba6d0f80-9358-11ed-9c94-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=165862 Naravoslovnotehniška fakulteta 0 0 0