Poly(methyl methacrylate)/polyphosphate blends with tunable refractive indices for optical applications

Tuning the refractive index of the transparent materials is essential for optical applications. Herein, we report novel materials with a tunable refractive index that are prepared by blending poly(methyl methacrylate) (PMMA) with different concentrations of two polyphosphate hybrid polymers (P1 and P2), having phosphorus in the main chain. The refractive indices and associated optical parameters of these polymers and hybrid materials (PB1 and PB2 series) are investigated using ellipsometry and optical modelling method to find their applicability in optics. Refractive indices of these materials are fine-tuned by altering the ratio of PMMA to P1 or P2. This approach is simple and ideal for obtaining homogeneous blends. Refractive index tunability of 0.05 and 0.1 are achieved for PB1 and PB2 series, respectively, by this approach. Abbe numbers of these blends are reasonable for PB1 series compared to the conventional lens materials, with a maximum value of 56 achieved in the case of PB120 blend. In addition, the trend in variation of extinction coefficient with wavelength for blends PB250, PB260 and PB280 seem promising for optical filter kind of applications. These results show that the synthesized polymer blends are promising as optical materials with refractive index tunability.