Paper Title
The Effect of Hybrid Pigments on The Thermal and Barrier Properties of Elastomer Composites

Abstract
Recently, inorganic-organic hybrid pigments have become very interesting to many scientists due to their extraordinary thermo- as well as photostability. An important advantage of hybrid pigments is their ability to combine the properties of organic dye with an inorganic matrix. This unusual feature makes them very attractive as new colorful fillers for polymer composites. The type of inorganic host plays a crucial role in the properties of hybrid pigments. Presently, special attention is paid to layered double hydroxides (LDH) due to their facile synthesis, non-toxicity, adsorption capacity and very high anion exchange ability. LDH is a layered anionic clay with the brucite-like structure described by the formula: [M2+1-xM3+x(OH)2]x+An-x/n∙mH2O, where M2+ and M3+ are di- and trivalent metal ions, respectively, and An- is the interlayer anion (e.g. CO32-, NO3-, F-, Cl-) which can be easily displaced by other organic molecules. Hence, in this work a few hybrid composites based on the azoic dyes and layered double hydroxides have been prepared and analyzed in detail by use XRD, SEM as well as spectrophotometric techniques. Obtained inorganic-organic pigments were incorporated into acrylonitrile-butadiene rubber (NBR) matrix. The effect of colorful hybrid fillers on the rheometric, mechanical, thermal and barrier properties of NBR composites was investigated. In addition, the morphology of polymer compounds was characterized by scanning electron microscopy (SEM). The experimental results clearly indicate that obtained inorganic-organic pigments exhibited high thermal stability and excellent chemical resistance. The application of prepared hybrid pigments allowed obtaining colored elastomer composites with improved barrier properties as well as reduced flammability. Furthermore, the obtained NBR composites were characterized by slightly improved mechanical strength. The authors gratefully acknowledge the financial support from National Science Center of Poland (Miniatura no. 2017/01/X/ST5/01105). Keywords: Barrier Properties, Hybrid Pigments, Elastomer Composites, Thermal Stability, Flammability