Development and Application of <scp>PMMA</scp> / <scp>MMA</scp> Binary Liquid Resin: From Viscosity Control and Mechanical Properties to Preparation of <scp>CF</scp> / <scp>PMMA</scp> Composites

ABSTRACT This study employed a binary liquid resin system composed of poly(methyl methacrylate) (PMMA) and methyl methacrylate (MMA). By adjusting the molecular weight of the pre‐dissolved PMMA and its ratio to MMA, resins (PMMA liquid resin) with different viscosities were prepared. Four redox initiation systems BPO/DMA (benzoyl peroxide/ N , N ′‐dimethyl‐p‐toluidine), BPO/DMT, LPO/DMA, and LPO/DMT (lauroyl peroxide/ N , N ′‐dimethylaniline) were selected to systematically investigate their effects on the polymerization exotherm, curing time, and the mechanical properties of the post‐cured material. Through mechanical property testing, analysis of molecular weight and its distribution, and thermal performance analysis, the optimal system parameters were determined. The results indicate that the PM‐10 resin (100 mPa s), with an initiation system of n MMA :n BPO :n DMA = 200:1.2:1, achieves optimal mechanical properties in the resulting pure resin. Furthermore, the CF/PMMA composites prepared using this system exhibit excellent macroscopic mechanical properties, with a tensile strength of 980.43 MPa and a tensile modulus of 74.15 GPa. This study confirms that through synergistic control of viscosity and the initiation system, the PMMA liquid resin system can achieve a combination of low‐temperature controllable polymerization and favorable mechanical performance, offering a viable option as a resin matrix for fiber‐reinforced composites.