The Effect of IPN Thermoplastic on Bonding Properties of Fibre-reinforced-composite

Objectives: To evaluate the effect of interpenetration polymer network (IPN) on bonding properties on UDMA/MMA based fiber-reinforced composite. IPN-phase was formed either using PMMA or PMMA-co-polymer.
Methods: Materials used in this study are UDMA(90%,Esschem)-MMA(10%,Sigma) based resin. Used IPN-component was either PMMA(150kD,Sigma-Aldrich) or PMMA-copolymer(150kD,Sigma-Aldrich). 0.5% or 2% IPN-thermoplastic was added UDMA-MMA resin having 0.7wt% camphorquinone and DMAEMA 0.7wt%.
0.5% PMMA was added to Group2 and 2% PMMA Group3. PMMA-coPolymer was added to 0.5%(Group5) and 2%(Group6) respectively. No polymers added resin was also made as control(Group1,4). For fibre-reinforced specimens, one bundle of S-glass fibres(tex 2400,Ovens-Corning) are impregnated with each resin(30min) and then placed in the hole of acrylic-resin. After placement, resin impregnated fibres were light cured(60sec). Using all kinds of mixed resin shown above, shear bond strength(SBS) test specimens were fabricated(total 60,n=10/Group). For SB test, composite resin (Gradia core,GC Corp)was build-up(3.6mm diameter x 2mm thickness) to surface of specimen and light-cured(60sec). Specimen of SBS test was fixed to mounting jig and load was applied at crosshead speed of 1.0mm/min. The results were analyzed by two-way ANOVA.
Results: Summary of SBS are shown at table below (MPa). The maximum mean SBS was 19.92MPa (2%PMMA) and minimum was 17.76MPa (no-polymer). ANOVA revealed that PMMA increased SBS values when PMMA-IPN phase was increased. Type of thermoplastic had significant effect also for bonding.
Conclusions: The results showed that increasing of PMMA-IPN component with fibre-reinforcement is effective for increasing of SBS. Therefore, it is considered that there would be significant effect for bonding properties.