PMMA (polymethylmethacrylate) and borax doped copolymer were synthesized by using atom transfer radical polymerization method. The uses of this copolymer were evaluated to spread it and to a wider area of use or to place it in specialized use in certain areas for the application fields of this copolymer. The results of the XPS analysis presented the bonds formed between C, O, B, and Cu and the types of bonds (single, double, or triple bond) based on the binding energies of the atoms. PMMA/Borax composite has presented that there was a relation between the chemical features of surface bonding and the modification of the dielectric properties with smaller values with the change of the borax amount. The behaviour of low reflection of broadband waves (500 MHz—50 GHz) interacting with the composite was influenced by several factors (including the modification of the composite's composition by borax at the optimum amount). The low reflection of broadband waves (500 MHz—50 GHz) was modified by the strengthened bonds as the result of the chemical development at the surface structure. The transmittance of the X-band microwave signal has been performed through the material for the use of the radome application. The passing of the signal to the other side of the material was provided by the maximum attenuation of 2.74 dB for use in the potential radome applications.