High Glass Transition Temperature of Copolymers based on 2,2,2-Trifluoroethyl Methacrylate and 2-(Trifluoromethyl) Styrene For Optical Fibers: Synthesis and Structure M. Raihane 1 , B. Wang 2 , Q. Du 2 , Y. Okamoto 2 1Laboratory of Organometallic and Macromolecular Chemistry - Composite Materials Faculty o fSciences and Technologies - Cadi Ayyad University. B.P. 549- 40000 Marrakech, Morocco 2 Polymer Research Institute, Polytechnic Institute of New York University, 6 Metrotech Center, Brooklyn, NY 11201, USA E-mail: m.raihane@uca.ma Abstract Polystyrene (PS) is an important commercially polymer with good light transmittance. The favorable physical properties of PS coupled with ease of processing make it useful as optical device materials [1]. However, high losses in the visible and near infrared region are dominated by the combinations of stretch and deformation vibrations of C-H bonds [2].When heavier atoms such as deuterium or fluorine replace the hydrogen atoms in C-H bond, the band vibration energy is decreased and thus the absorption band is minimized. Thus, fluorine containing polystyrene such as poly(2,3,4,5,6-pentafluorostyrene)and poly(4- trifluoromethyl 2,3,5,6-tetrafluorostyrene) were synthesized [3]. They are thermally stable and transparent, but their glass transition temperatures (Tg) were about 110 °C. However, some applications such as in automobile and airplane require optical polymers with higher Tg (>120 °C) [4]. Bomer and Hagemann [5] reported that when CF 3 group substituted on the ortho position of polystyrene, the Tg was considerably higher (175 °C) than those where CF 3 are on the meta and para positions whose Tgs were 63 and 101 °C, respectively. Okamoto et al. [6] are investigated the CF 3 substituted polystyrenes for possible optical polymer materials with higher Tg. Various fluorine containing styrene monomers were synthesized and the polymerization rates of these styrene monomers in benzene and dioxane solutions were measured. The thermal and optical properties of the trifluoromethyl substituted styrenes homopolymers as well as their copolymers were also reported. In addition, poly(2,2,2-trifluoroethyl methacrylate) (poly(TFEMA))-based GI POF provides a surprisingly low attenuation127–152 dB/km at 670–680 nm relative to that for (poly(methyl methacrylate)) PMMA- based GI POF. Although the number of C-H bonds per monomer unit between TFEMA and MMA differ by only one, the trifluoroethyl group of TFEMA possesses a large volume, and the number of C-H bonds per unit volume in poly(TFEMA) is only 64% to that in PMMA. However, the long side chain not only reduces fiber attenuation but also lowers Tg [7,4c]. In the frame of a research aiming at developing new transparent fluoropolymers with high Tg, radical copolymerizations of 2,2,2-trifluoroethyl methacrylate (TFEMA) and 2-(trifluoromethyl) styrene (2TFMS) were carried out at 60 °C using AIBN as the initiator (Scheme 1). AIBN C n m 2TFMS y x 60 °C H 2 C TFEMA poly(TFEMA-co-2TFMS) CO 2 CH 2 CF 3 CH 3 CH H 2 C CF 3 C H 2 C CO 2 CH 2 CF 3 CH 3 C H 2 C H CF 3 Scheme 1. Synthetic routes of poly(TFEMA-co-2TFMS) copolymers Poster Fluoropolymer 2014