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Transparent thermoplastic polymers that exhibit no birefringence are ideal for optical components such as optical films for liquid crystal displays and various lenses. Copolymerization of a positive birefringent monomer with a negative monomer is an effective technique for obtaining low birefringent polymers, especially zero-photoelastic birefringence polymers that exhibit no photoelastic birefringence even during elastic deformation. We prepared four types of trifluoromethyl-substituted polystyrenes. By substituting hydrogens at the ortho or meta positions of the benzene ring of polystyrene, we demonstrated that poly(2-(trifluoromethyl)styrene), poly(3-(trifluoromethyl)styrene), and poly(3,5-bis(trifluoromethyl)styrene) had negative photoelastic coefficients. However, poly(4-(trifluoromethyl)styrene) had a positive photoelastic coefficient similar to that of polystyrene. Based on these results, we synthesized a zero-photoelastic birefringence polymer of poly(2-(trifluoromethyl)styrene-co-4-(trifluoromethyl)styrene) (55/45 wt.) exhibiting no photoelastic birefringence in elastic deformation, in which the positive photoelastic birefringence of the poly(4-(trifluoromethyl)styrene) unit was compensated for by the negative photoelastic birefringence of the poly(2-(trifluoromethyl)styrene) unit. The discovery of polymers having negative photoelastic coefficients is valuable for the design and synthesis of zero-photoelastic birefringence polymers. The four types of trifluoromethyl-substituted polystyrenes are promising optical materials because they have high transparency (transmittance > 89-92% for 27-34-µm thickness films) in the visible and near-infrared regions and a high decomposition temperature of approximately 400°C. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

To address the need for perfluoro polymers with higher Tg, we have prepared and characterized various perfluorodioxolane monomers via direct fluorination of the hydrocarbon precursors. These monomers were readily polymerized in bulk or in solution initiated by perfluorodibenzoyl peroxide. The polymers obtained have relatively high Tg(~160°C) and exhibited low material dispersion. These polymers are completely amorphous and soluble in fluorinated solvents. The polymers are also chemically and thermally stable ( Tg > 300°C). Thus, these perfluorodioxolane polymers may be used as plastic optical fiber material where high Tg is required, such as in automobile and aircraft application. These perfluorodioxolane polymers were also investigated for use as gas separation membrane. Among these polymers, the copolymer of perfluoro (2-methylene-1,3-dioxolane) and perfluoro (2-methylene-4,5-dimethyl dioxolane) showed superior gas separation performance compared with the commercial perfluoro polymers for a number of gas pair, including CO2/CH4, He/CH4, H2/CH4, and N2/CH4. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Thermal and optical properties of copolymers of 1-adamantyl methacrylate (AdMA) and styrene (St) prepared by free radical polymerization in the bulk are investigated. The copolymer forms an azeotrope when the composition is AdMA/St = 55/45 mol%. The glass transition temperature and decomposition temperature of the azeotropic copolymer are 170 and ca 340 °C, respectively. The refractive index increases nonlinearly with St content from 1.522 to 1.591. The light scattering loss at 633 nm is 28.1 dB km−1, which is less than half of that of polystyrene. The total optical loss including molecular vibrational absorption, which is evaluated using a copolymer-based optical fiber, is 292-645 dB km−1 at 500-700 nm. These values correspond to transmittances of 86-93% for a 1 m optical path length. © 2014 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Graded-index plastic optical fibers, composed of doped polymers, have advantages over conventional glass optical fibers, but need to be developed further for practical application. Here, a variety of aromatic sulfide dopants were synthesized, and their effects on the refractive indexes and glass transition temperatures ( Tg) of poly(methyl methacrylate) and methyl 2-chloroacrylate/2,2,2-trichloroethyl methacrylate copolymers were studied. While polymers containing large dopants exhibited relatively high refractive indices, their Tg values were low, making these materials unsuitable for graded-index plastic optical fiber applications. Six dopants yielded polymers that exhibited higher Tg values than the conventionally used (diphenyl sulfide)-doped polymer. The dopant dibenzothiophene, in particular, yielded polymers with the highest refractive indexes and Tg values, and polymers containing (phenylthio)benzene dopants also performed well. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Polystyrene (PS) was selected as a costless polymer matrix for graded index polymer optical fibers (GI POFs) with low attenuation at a wavelength of 670 nm. However, fabricated PS-based GI POFs showed attenuation of more than 300 dB/km. This high attenuation PS-based GI POF had a quite broad molecular weight distribution. In contrast, a PS-based GI POF with a narrow molecular weight distribution showed low attenuation of around 160 dB/km. This is because the refractive index of PS, different from general polymers, is greatly affected by the molecular weight. The PS-based GI POF showed the high thermal stability of this low loss performance at a temperature of 70^\circC, despite the low glass transition temperature caused by plasticization. The measured refractive index profile was near optimum (g=2.5), and a high bandwidth of 5.8 GHz for a 50 m length was obtained. [ABSTRACT FROM PUBLISHER]

Plastic optical fibers (POFs) are highly promising transmission media for future home networking.In comparison to glass optical fibers (GOFs), which are commonly used in core and metropolitan networks, POFs offer many advantages such as great flexibility and easy handling. This review begins with the basic concepts of optical fibers and moves on to the early history of loss reduction in POFs. What drastically changed the status of POFs in the communications field was a graded-index technology that improved the bandwidth to over 1 gigabits per second. However, even after the loss and bandwidth were enhanced to their limits, the performances of POFs were insufficient for market demand when using conventional optical polymer materials such as poly(methyl methacrylate). Recently, this problem has been solved by several lines of material research using fluorinated polymers. As a result, high-speed optical home networking by POFs has become more realistic. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011 [ABSTRACT FROM AUTHOR]