Fabrication of polycarbonate-based polymer optical fiber cladding: Effect of different solvents

Normally, the cladding layer is fabricated by using heat through continuous extrusion, melt spinning, batch extrusion, and heat drawing technique. These techniques require high temperature precision in order to obtain the desired morphology of the cladding without compromising the quality of the polymer. Hence, in this study dip-coating method was utilized to coat the polycarbonate (PC) core with poly (methyl methacrylate) (PMMA) as a cladding part. The PC core was dipped into different cladding solutions using three types of organic solvent (i.e. Tetrahydrofuran (THF), N-Methyl-2-pyrrolidone (NMP), and Dimethylacetamide (DMAc) and subjected to post-treatment process. The thickness of fabricated cladding layer was ~10–15 μm for all coating solutions. The cladding prepared by THF exhibits transparent layer wrapping the core. However, the cladding layers for PMMA dissolved in NMP and DMAc showed translucent appearance. The THF/PMMA solvent displayed ~98 % transmittance at visible region which was higher than NMP/PMMA and DMAc/PMMA. The failure strain (3.6 %) and tensile strain (88.98 MPa) of THF/PMMA sample were higher compared to other solutions. Young’s modulus which measures the stiffness and represents the breakability of a solid material was lower for THF/PMMA. Therefore, the THF is the most appropriate solution for fabrication of PC-based POF cladding layer.