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Effect of boron oxide addition on the viscosity‐temperature behaviour and structure of phosphate‐based glasses
Author(s) -
Sharmin Nusrat,
Hasan Muhammad S.,
Rudd Chris D.,
Boyd Daniel,
WernerZwanziger Ulrike,
Ahmed Ifty,
Parsons Andrew J.
Publication year - 2017
Publication title -
journal of biomedical materials research part b: applied biomaterials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.665
H-Index - 108
eISSN - 1552-4981
pISSN - 1552-4973
DOI - 10.1002/jbm.b.33610
Subject(s) - materials science , magic angle spinning , fragility , boron , viscometer , boron oxide , viscosity , analytical chemistry (journal) , glass transition , fourier transform infrared spectroscopy , oxide , nuclear magnetic resonance spectroscopy , nuclear magnetic resonance , chemistry , composite material , organic chemistry , chemical engineering , polymer , physics , engineering , metallurgy
In this study, nine phosphate‐based glass formulations from the system P 2 O 5 ‐CaO‐Na 2 O‐MgO‐B 2 O 3 were prepared with P 2 O 5 content fixed as 40, 45 and 50 mol%, where Na 2 O was replaced by 5 and 10 mol% B 2 O 3 and MgO and CaO were fixed to 24 and 16 mol%, respectively. The effect of B 2 O 3 addition on the viscosity‐temperature behaviour, fragility index and structure of the glasses was investigated. The composition of the glasses was confirmed by ICP‐AES. The viscosity‐temperature behaviour of the glasses were measured using beam‐bending and parallel –plate viscometers. The viscosity of the glasses investigated was found to shift to higher temperature with increasing B 2 O 3 content. The kinetic fragility parameter, m and F 1/2 , estimated from the viscosity curve were found to decease with increasing B 2 O 3 content. The structural analysis was achieved by a combination of Fourier transform infrared spectroscopy and solid state nuclear magnetic resonance. 31 P solid‐state magic‐angle‐spinning nuclear magnetic resonance (MAS‐NMR) showed that the local structure of the glasses changes with increasing B 2 O 3 content. As B 2 O 3 was added to the glass systems, the phosphate connectivity increases as the as the Q 1 units transforms into Q 2 units. The 11 B NMR results confirmed the presence of tetrahedral boron (BO 4 ) units for all the compositions investigated. Structural analysis indicates an increasing level of cross‐linking with increasing B 2 O 3 content. Evidence of the presence of P‐O‐B bonds was also observed from the FTIR and 31 P NMR analysis. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 764–777, 2017.