Fabrication of a high fire safety, transparent coating for polymethylmethacrylate with superior hardness and adhesion

There has been a greatly extensive research interest in PMMA materials as alternatives to traditional glass. However, it remains tremendously challenging to integrate multiple functionalities into a PMMA material that can be diffusely applied to a flammable and complex scene. Herein, we fabricated a transparent, flame-retardant and high hardness coating based PMMA substrate through an in situ photo-polymerization by UV curing technology. The LOI test results showed that all coated PMMA obtained a good grade compared with pure sample, CPMMA-1 and CPMMA-4,5 can reach 24.5 and 24.0, respectively. The cone calorimeter experiment revealed that coated PMMA significantly enhanced fire safety, as the PHRR and THR values of CPMMA-1 were reduced by 48.6 % and 23.0 %, respectively. The FPI and FGI values of CPMMA-1 were 0.060 (m2·s)/kW and 2.8 kW/(m2·s) in comparison with 0.049 (m2·s)/kW and 10.4 kW/(m2·s) of pure PMMA. The large panel combustion test results revealed that CPMMA-1 and CPMMA-5 obtained the good fireproof property. Additionally, all coated PMMA achieved a satisfactory level about at least 3H and 3B level in hardness and adhesion test and were greatly improved compared with the pure sample. Furthermore, the coated PMMA can still maintain good transparency and visible light properties. Therefore, an innovative research idea and basis for the fabrication of flame-retardant PMMA materials are provided in this work. The manufacture of coated PMMA in this research provides a promising way and foresight into the design development for the next-generation of multifunctional fireproof PMMA materials.