Materials, Methods & Technologies ISSN 1314-7269, Volume 11, 2017 Journal of International Scientific Publications www.scientific-publications.net Page 46 TG/DTG/MS COUPLED METHODS FOR THERMAL ANALYSIS OF NEW MATERIALS FOR OPTICAL FIBER TECHNOLOGY Małgorzata Gil 1 , Beata Podkościelna 2 , Paweł Mergo 1 1 Laboratory of Optical Fibre Technology, Maria Curie-Skłodowska University, Lublin, Poland 2 Department of Polymer Chemistry, Maria Curie-Skłodowska University, Lublin, Poland Abstract In this study bulk polymerization of methacrylic derivative of thiophenol (PSM) with commercial monomers styrene (St) and methyl methacrylate (MMA) was presented. This monomers had been chosen because of their good thermal and optical properties, which make them useful in optical fibres technology. Copolymerization MMA or St with PSM in glass form, with different weight ratio of monomers (1:10, 1:20; MMA or St : PSM) was performed. As a initiator α,α’-azoiso-bis-butyronitrile (AIBN) was used. This process was carried out in water bath at 60 o C for 2 h and 90 o C for 12 h. As an analytical method coupled TG/DTG/QMS was used. Key words: thiophenol, copolymers, thermal properties, optical fibers 1. INTRODUCTION Typically optical fibers are made of glass, but in recent years, there can be observe an increased interest in polymer optical fibers (POFs). This relates to the differences in properties between them and the silica glass optical fibers. The fibers made of glass, mainly for telecommunication applications, have a relatively small diameter, usually 125µm, to allow them to be flexible despite of their inherent brittleness. This causes many problems during their connection. Polymer optical fibers can be produced with relatively large dimensions, which greatly simplify their connection. Unfortunately, polymer optical fibers have a higher attenuation, due to increased scattering. But still owing to its unique features such as low processing temperatures and great compatibility, which allow for the doping of a wide range of organic materials, makes polymer optical fibers the object of great interest. Due to the much lower Young’s Modulus and much higher thermos-optic coefficient POF may acquire special functionalities for many applications in photonics, material science, medicine and optical sensing [1-4]. The main problem in polymer optical fiber technology is the purity of the materials. Even a small amount of impurities can significantly decrease the transmission properties of the final product. This is why before the use all substances have to be purified. Another problem, which relates to the mentioned, are the thermal properties of the polymer matrix. To be able to draw a fiber from polymer preform, the polymer needs to have good thermal stability. For pol (methyl mathacrylate) and styrene this temperature is about 200 – 220 o C. Our studies showed [5] that after adding a dopant to the matrix, the temperature properties are changing. To increase the thermal resistance of the studied polymers and not to have to add another compound (which could cost a transmission lowering) we decided to add to the composition methacrylic derivative of thiophenol, which is well known also as a chain transfer agent [6-8]. This article presents the thermal and spectroscopic studies of copolymers MMA or St with new synthesized methacrylic derivative of thiophenol (PSM). The degree of usefulness of the received materials as optical materials has been studied using the coupled thermal and spectroscopic methods. Benefits resulting from the coupling of these methods rely on the fact that they give complementary data on the polymer molecule, which is very effective in the identification of unknown polymer materials. Moreover, chemical characterization of materials particularly for use in the manufacturing of optical fibers and also analysis of the chemical composition of the gases emitted from the heated sample affecting the properties of the produced fibers - definition of the causes of heterogeneity in fiber preforms. The analysis can get information on determination of the thermal processing of materials for optical applications and also determine how to prevent thermal decomposition of the samples.