Izabela M Barszczewska-Rybarek1, Anna Korytkowska-Wałach2, Małgorzata Kurcok3, Grzegorz Chladek4, Jacek Kasperski5. 1. Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, Gliwice, Poland. 2. Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Silesian University of Technology, Gliwice, Poland. 3. Institute for Engineering of Polymer Materials and Dyes, Paint and Plastics Department, Gliwice, Poland. 4. Institute of Engineering Materials and Biomaterials, Silesian University of Technology, Gliwice, Poland. 5. Chair of Prosthetics and Dental Materials, Department of Dental Prosthetics, Medical University of Silesia in Katowice, School of Medicine with the Division of Dentistry in Zabrze, Zabrze, Poland.
Abstract
PURPOSE: This paper presents the study aimed at the development of crosslinked poly(methyl methacrylate)s (X-PMMA) of varied crosslink density and the investigation of the relationships between the polymer network structure and dynamic mechanical properties. METHODS: A series of model X-PMMA networks were crosslinked by the introduction of: 1, 2, 5, 10 and 20% of triethylene glycol dimethacrylate (TEGDMA). The copolymerizations led to various glass-rubber relaxation properties of the polymer networks, as revealed by dynamic-mechanical analysis (DMA). Glass temperature (Tg) and storage modulus above the Tg (Erubbery ) were a sensitive function of network architecture. DMA data were used for calculating the network parameter (Mc), crosslink density (q) and its alternative measure - the degree of crosslinking (DX). RESULTS: The viscoelastic properties as well as structural parameters calculated from those showed correlation with the amount of the crosslinker. The increase in TEGDMA content resulted in the Tg, q and DX increases, whereas Mc decrease. The possible incomplete conversion of double bonds was detected in the DMA analysis, which was confirmed by the degree of conversion (DC), measured by FTIR spectroscopy. Additionally, some amount of sol fraction was found by 1H NMR experiments. CONCLUSIONS: The structure-property relationships developed for the system presented in this work could be useful in tissue engineering, where X-PMMA is applied. The direct measure of storage modulus values before and above glass transition may serve as a simple and fast indicator of the X-PMMA crosslink density.
PURPOSE: This paper presents the study aimed at the development of crosslinked poly(methyl methacrylate)s (X-PMMA) of varied crosslink density and the investigation of the relationships between the polymer network structure and dynamic mechanical properties. METHODS: A series of model X-PMMA networks were crosslinked by the introduction of: 1, 2, 5, 10 and 20% of triethylene glycol dimethacrylate (TEGDMA). The copolymerizations led to various glass-rubber relaxation properties of the polymer networks, as revealed by dynamic-mechanical analysis (DMA). Glass temperature (Tg) and storage modulus above the Tg (Erubbery ) were a sensitive function of network architecture. DMA data were used for calculating the network parameter (Mc), crosslink density (q) and its alternative measure - the degree of crosslinking (DX). RESULTS: The viscoelastic properties as well as structural parameters calculated from those showed correlation with the amount of the crosslinker. The increase in TEGDMA content resulted in the Tg, q and DX increases, whereas Mc decrease. The possible incomplete conversion of double bonds was detected in the DMA analysis, which was confirmed by the degree of conversion (DC), measured by FTIR spectroscopy. Additionally, some amount of sol fraction was found by 1H NMR experiments. CONCLUSIONS: The structure-property relationships developed for the system presented in this work could be useful in tissue engineering, where X-PMMA is applied. The direct measure of storage modulus values before and above glass transition may serve as a simple and fast indicator of the X-PMMA crosslink density.
Authors: Johannes G H Hermens; Thomas Freese; Keimpe J van den Berg; Rogier van Gemert; Ben L Feringa Journal: Sci Adv Date: 2020-12-16 Impact factor: 14.136