Characterisation of melamine formaldehyde microspheres synthesised with prolonged microencapsulated reaction time

Leskovšek, Mirjam (author), Kortnik, Jože (author), Stanković Elesini, Urška (author), Šumiga, Boštjan (author)

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.

• Language: English
• Keywords: characterisation, curing, melamine formaldehyde resin, microsphere, reaction time
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2022
• Number of pages: Str. 288–297
• Numbering: Vol. 42, iss. 4
• PID: 20.500.12556/RUL-143845
• UDC: 677
• ISSN on article: 2191-0340
• DOI: 10.1515/polyeng-2021-0289
• COBISS.SI-ID: 97846019
• Publication date in RUL: 13.01.2023

Record is a part of a journal

• Title: Journal of polymer engineering
• Shortened title: J. polym. eng.
• Publisher: De Gruyter
• ISSN: 2191-0340
• COBISS.SI-ID: 54975235

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: karakterizacija, zamreževanje, melamin formaldehidna smola, mikrosfere, reakcijski čas