Polymer Testing 82 (2020) 106290 Available online 16 December 2019 0142-9418/© 2019 Elsevier Ltd. All rights reserved. Material Properties Impact of organic-inorganic color additive on the properties of ethylene-norbornene copolymer Anna Marzec a, * , Bolesław Szadkowski a , Małgorzata Ku� smierek a , Jacek Rogowski b , Waldemar Maniukiewicz b , Przemysław Rybi � nski c , Marian Zaborski a a Institute of Polymer and Dye Technology, Faculty of Chemistry, Lodz University of Technology, Stefanowskiego 12/16, 90-924, Lodz, Poland b Institute of General and Ecological Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924, Lodz, Poland c Institute of Chemistry, Jan Kochanowski University, Kielce, Poland A R T I C L E INFO Keywords: Aluminum-magnesium hydroxycarbonate Physico-chemical characterization Organic-inorganic pigment Polymer composite Photostability Flame retardancy ABSTRACT In this study, we developed a new organic-inorganic pigment (LP) by precipitation of dye molecules onto aluminum-magnesium hydroxide (LH). The morphology and physico-chemical properties of the pigment were characterized by X-ray diffraction analysis (XRD), secondary ion mass spectrometry (TOF-SIMS), 27-Al solid- state nuclear magnetic resonance (NMR) spectroscopy, scanning electron microscopy (SEM) and thermogravi- metric analysis (TGA). The incorporation of the azo dye into the LH host caused an increase in the interlayer distances of the LP from 0.751 to 0.758 nm. The LP pigment also showed better thermal- and photo-stability than the pristine azo chromophore. The novel organic-inorganic additive was next applied as a fller at different concentrations (2 phr, 5 phr, 10 phr) to obtain colorful ethylene-norbornene (EN) flms. The morphological, mechanical and fame-retardant properties of the composites were determined by XRD, SEM, dynamic- mechanical analysis (DMA) and cone calorimetry tests (CCT). The EN flms containing the LH/Azo dye demonstrated improved mechanical, barrier and fame-retardant properties. Compared to the neat EN copolymer and EN/LH composite, the EN/LP sample was found to be the most resistant to UV aging, as confrmed by FTIR and mechanical analysis. 1. Introduction Organic-inorganic hybrid materials have attracted increasing atten- tion in recent years, due to their ability to combine the advantages of their organic and inorganic components [1,2]. This is refected by the growing number of publications containing references to hybrid mate- rials. Organic-inorganic materials with outstanding physico-chemical properties and multifunctionality represent a new feld of basic research. Organic-inorganic colorants are considered to be one of the most promising groups of hybrid materials [3–7]. Dyes are organic compounds which are usually applied to ensure the color fastness or to change the color of a material [8]. However, in comparison to pigments, which are solid particles, they have many disadvantages, such as low melting points and high tendencies to migrate and degrade. This limits the application of dyes in many areas. Most of the disadvantages of dyes can be overcome by transforming the organic chromophores into the insoluble form of pigments. The organic-inorganic colorant group combines the most desirable properties of organic pigments, such as their wide range of colors including colors with high intensity, with those of inorganic pigments, such as high resistance to light, temperature and organic solvents [9–11]. Stabilization and immobilization of organic dyes on inorganic hosts has been reported for different carriers, such as layered double hydroxides, gamma-alumina, silica, organo-modifed silica, TiO 2 and zeolites [12–20]. Many different clays, including bentonite, smectite clay or synthetic fuorinated mica, have also been identifed as suitable inorganic matrices for organic components, based on their swelling properties and their characteristics as soft matter materials [21–24]. Generally, research has confrmed that these minerals are potential candidates for producing new colorants with vivid colors as well as high thermal and chemical stability. Organic-inorganic pigments offer an attractive alternative to conventional coloring agents, due to the possi- bility of combining coloring ability with the functionality of polymer fllers. In recent years, several studies have been conducted on the synthesis and application of organic-inorganic pigments. Marchante et al. [25,26] * Corresponding author. E-mail address: anna.marzec@p.lodz.pl (A. Marzec). Contents lists available at ScienceDirect Polymer Testing journal homepage: http://www.elsevier.com/locate/polytest https://doi.org/10.1016/j.polymertesting.2019.106290 Received 8 August 2019; Received in revised form 8 December 2019; Accepted 10 December 2019