Effect of Interpenetrating Polymer Network (IPN) Thermoplastic Resin on Flexural Strength of Fibre-Reinforced Composite and the Penetration of Bonding Resin into Semi-IPN FRC Post

• Published in: Polymers Vol. 13; no. 18; p. 3200
• Main Authors: Hatta, Minori, Shinya, Akikazu, Gomi, Harunori, Vallittu, Pekka K., Säilynoja, Eija, Lassila, Lippo V. J.
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 21.09.2021; MDPI
• Subjects: Bonding strength; Composite materials; Copolymers; Curing; Fiber composites; Fiber reinforced polymers; Fiber reinforcement; fibre post; fibre-reinforced composite; Flexural strength; Impregnation; Interpenetrating networks; interpenetrating polymer network; Light; Penetration; Photomicrographs; PMMA; Polymerization; Polymers; Polymethyl methacrylate; post and core; Resins; Scanning electron microscopy; Thermoplastic resins; St Louis Missouri; United States > US
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym13183200

The purpose of this study was to evaluate the effects of interpenetrating polymer network (IPN) thermoplastic resin on the flexural strength of fibre-reinforced composite (FRC) with different IPN polymer compositions. The penetration of bonding resin into semi-IPN FRC posts was also evaluated. The IPN thermoplastic resin used was UDMA-MMA monomer with either PMMA (0.5%, 2%, 5%) or PMMA-copolymer (0.5%, 2%). A no added IPN polymer resin was also made. Mixed resin was impregnated to S- and E-glass fibre rovings. These resins and resin impregnated fibres were used for flexural strength (FS) test. To evaluate the penetration of bonding resin into semi-IPN post, SEM observation was done with various impregnation time and polymerization mehods (hand-light- and oven-cure). The result of FS was recorded from 111.7 MPa (no-IPN polymer/no-fibre-reinforcement) to 543.0 MPa (5% PMMA/S-glass FRC). ANOVA showed that there were significant differences between fibre-reinforcement and no-fibre-reinforcement (p < 0.01) both in S- and E-glass fibre groups, and between 0.5% PMMA and 5% PMMA in the S-glass FRC group. SEM micrographs showed that the penetration layers of bonding resin into hand-light cured semi-IPN posts were different according to impregnation time. Fibre reinforcement is effective to improve flexural strength. The depth of penetration layer of bonding resin into semi-IPN matrix resin was improved when a hand-light cure was used.