Light-focusing plastic rod prepared by photocopolymerization of methacrylic esters with vinyl benzoates

Abstract

A new preparation method of a light‐focusing plastic rod (LFR) is reported, where the photocopolymerization of methacrylic esters (M₁) such as methyl methacrylate (MMA) with vinyl benzoates (M₂) such as vinyl benzoate (VB), vinyl o‐chlorobenzoate, and vinyl o,p‐dichloro‐benzoate was carried out. The M₁‐M₂ mixture placed in a glass tube was exposed to uv light by rotating a glass tube about its axis. LFR prepared from a MMA‐VB pair has a quadratic gradient constant with a refractive index A= (3∼11) ×10⁻³ mm⁻², an internal loss of light transmission IL= (3∼12) dB/m, and a ratio of the radius of the imaging region to the rod radius (r_i/r_p) =0.5∼0.7.