One promising thermoplastic material: Poly(methyl methacrylate) and its continuous glass fiber reinforced composites by redox polymerization

Abstract Recently, thermosetting epoxy resin is expected to be substituted by thermoplastic featured from green circular economy. Poly(methyl methacrylate) (PMMA) has been well known as one promising thermoplastic resin, although its mechanical property needs to be further investigated. In this paper, the free radical polymerization of methyl methacrylate (MMA) was initiated by lauroyl peroxide/ N,N ‐dimethylaniline (LPO/DMA) and lauroyl peroxide/ N,N ‐dimethyl‐p‐toluidine (LPO/DMT) redox system at room temperature, respectively. The PMMA ( n (MMA:LPO:DMA) = 200:1.2:1) exhibited excellent mechanical properties, and the tensile strength was 66.5 MPa, the bending strength was 118.0 MPa. The tensile strength increased to 78.9 MPa at −40°C, which suggested a promising application at low temperature. The resin was applied to fabricate continuous glass fiber reinforced PMMA (GF/PMMA) composites by vacuum‐assisted resin infusion. The 0° tensile strength and modulus were 1.17 and 43.7 GPa and 90° tensile strength and modulus were 48.3 MPa and 13.2 GPa, respectively. The mechanical properties of GF/PMMA composites are higher than GF/epoxy. Moreover, PMMA resin and glass fiber can be recycled from GF/PMMA composites by MMA as solvent, which is more energy‐efficient and environment‐friendly. This work is of great significance for preparing sustainable resin and composites. Highlights GF/PMMA composites were fabricated by vacuum perfusion. GF/PMMA composites showed higher mechanical properties than GF/epoxy. GF/PMMA composite was recycled with MMA and closed‐loop recovery was achieved.