Vm. Miettinen et al., Water sorption, solubility and effect of post-curing of glass fibre reinforced polymers, BIOMATERIAL, 20(13), 1999, pp. 1187-1194
Different polymer matrices are used for dental glass fibre composites. The
aims of this study were to determine water sorption and solubility of glass
fibre composites with different polymer matrices. In addition, the effect
of post-curing of matrix polymers with heat on the water sorption and solub
ility values was investigated. Commercial one-phase and two-phase (powder-l
iquid) monomer systems were used in polymer matrix of E-glass fibre composi
te. Rhombic unreinforced and fibre reinforced test specimens were polymeriz
ed by autopolymerization or by light only, or additionally post-cured with
heat. Water sorption and solubility determination method was based on ISO/D
IS 1567-1997 draft for international standard with 7 d immersion time. In a
ddition, water sorption was measured at second time for 30 d immersion time
to determine saturation time of test specimens by water. Five test specime
ns of unreinforced polymer and reinforced polymer were tested and the quant
ity of fibres was determined by combustion analysis. Water sorption values
of different brands of polymer matrices ranged from 0.9 to 8.3 wt% (P < 0.0
01, ANOVA). High sorption values were explained by microscopic voids in the
polymer matrix and by composition of polymer matrix. Solubility values ran
ged from 0.02 to 2.5 wt% (P < 0.001, ANOVA). Generally, fibre inclusion and
post-curing of polymer matrix reduced water sorption and solubility. The r
esults of this study suggest that the water sorption and solubility of fibr
e composites varies according to the brand of polymer matrix and homogenity
of polymer matrix. Water sorption of polymer matrix might influence hydrol
ytic stability of polymer-glass fibre composite. (C) 1999 Elsevier Science
Ltd. All rights reserved.