MECHANICAL, THERMAL AND FLAMMABILITY PROPERTIES OF HUNTITE HYDROMAGNESITE REINFORCED POLYURETHANE ELASTOMER A THESIS SUBMITTED TO THE GRADUATE SCHOOL OF NATURAL AND APPLIED SCIENCES OF MIDDLE EAST TECHNICAL UNIVERSITY BY TÜRKAN GÜLER IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN POLYMER SCIENCE AND TECHNOLOGY FEBRUARY 2017 ii Approval of the thesis; MECHANICAL, THERMAL AND FLAMMABILITY PROPERTIES OF HUNTITE HYDROMAGNESITE REINFORCED POLYURETHANE ELASTOMER submitted by TÜRKAN GÜLER in partial fulfillment of the requirements for the degree of Master of Science in Polymer Science and Technology Department, Middle East Technical University by, Prof. Dr. Gülbin Dural Ünver ____________ Dean, Graduate School of Natural and Applied Sciences Prof. Dr. Necati Özkan _____________ Head of Department, Polymer Science and Technology Prof. Dr. Erdal Bayramlı _____________ Supervisor, Chemistry Dept., METU Assoc. Prof. Dr. Mehmet Doğan _____________ Co-Supervisor, Textile Engineering Dept. Erciyes University Examining Committee Members: Prof. Dr. Teoman Tinçer _________________ Chemistry Dept., METU Prof. Dr. Erdal Bayramlı _________________ Chemistry Dept., METU Doç. Dr. Ali Çırpan _________________ Chemistry Dept., METU Prof. Dr. Necati Özkan _________________ Polymer Science and Technology Dept., METU Prof. Dr. Mehmet Saçak _________________ Chemistry Dept., Ankara University Date: February 2, 2017 iii I hereby declare that all information in this document has been obtained and presented in accordance with academic rules and ethical conduct. I also declare that, as required by these rules and conduct, I have fully cited and referenced all material and results that are not original to this work. Name, Last name: Türkan Güler Signature: iv ABSTRACT MECHANICAL, THERMAL AND FLAMMABILITY PROPERTIES OF HUNTITE HYDROMAGNESITE REINFORCED POLYURETHANE ELASTOMER Güler, Türkan M.S., Department of Polymer Science and Technology Supervisor: Prof. Dr. Erdal Bayramlı Co-Supervisor: Assoc. Prof. Dr. Mehmet Doğan February 2017, 102 pages Polyurethane elastomer (Thermoplastic Polyurethane-TPU) has desirable properties for many applications including footwear, packaging, protective coatings, cables, wires and tubes in the mainly automotive and construction industries. Huntite and Hydromagnesite are naturally occurring minerals that has been used as fire retardants commercially since the late 1980’s. The World’s largest reserve of this mineral has been found in Turkey. The main purpose of present work is to investigate the combustion and thermal degradation characteristics of the flame retardant TPU based composites containing huntite and hydromagnesite with and without expandable graphite. The combustion v and the thermal degradation characteristics of composites are investigated by LOI, UL-94 standard, thermogravimetric analysis (TGA) and mass loss calorimeter. Char residues remained after mass loss calorimeter test are investigated by conducting attenuated total reflectance – Fourier-transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. The mechanical properties of the composites are also investigated by tensile testing and dynamic mechanical analysis (DMA). Keywords: huntite, hydromagnesite, thermoplastic polyurethane, flame retardancy, mechanical properties vi ÖZ HUNTİT HİDROMAGNEZİT TAKVİYELİ POLİÜRETAN ELASTOMERİNİN MEKANİK, TERMAL VE YANMAZLIK ÖZELLİKLERİNİN İNCELENMESİ Güler, Türkan Yüksek Lisans, Polimer Bilimi ve Teknolojisi Bölümü Tez Yöneticisi: Prof. Dr. Erdal Bayramlı Ortak Tez Yöneticisi: Doç. Dr. Mehmet Doğan Şubat 2017, 102 sayfa Poliüretan elastomer (Termoplastik Poliüretan-TPU) sağladığı üstün özellikleri nedeni ile özellikle otomotiv ve inşaat endüstrisinde, ayakkabı, ambalaj, koruma kıyafetleri, kablolar, teller, borular gibi pek çok alanda kullanılmaktadır. Huntit ve hidromagnezit 1980 den bu yana alev geciktirici olarak kullanılan doğal minerallerdir. Bu mineralin dünyadaki en büyük rezervi Türkiye’dedir. Mevcut çalışmanın temel amacı alev geciktirici huntit ve hidromanyezit içeren TPU esaslı kompozitlerin, genleşen grafit ile ve genleşen grafit kullanılmadan, yanma ve termal bozunma özelliklerinin araştırılmasıdır. vii Kompozitlerin yanma ve termal bozunma özellikleri LOI, UL-94 standardı, termogravimetrik analiz (TGA) ve kütle kaybı kalorimetre ile incelenmiştir. Kütle kaybı kalorimetre testinden sonra kalan kalıntılar, toplam yansıma geçirgenliği azltılmış – Fourier dönüşümlü kızılötesi spektrometre (ATR-FTIR), X-ışını kırınımı (XRD) ve taramalı elektron mikroskobu (SEM) ile incelenmiştir. Kompozitlerin mekanik özellikleride, çekme testi ve dinamik mekanik analiz (DMA) ile incelenmiştir. Anahtar Kelimeler: huntit, hidromagnezit, termoplastik poliüretan, yanmazlık, mekanik özellikler viii To my family ix ACKNOWLEDGEMENTS I would like express my gratitude to my thesis supervisor Prof. Dr. Erdal Bayramlı for his understanding, support and guidance. I am grateful that he always appreciated and encouraged me during my thesis studies. I would like sincerely thank to my co-supervisor Assist.Prof.Dr.Mehmet Doğan for his invaluable guidance, support and help. This study was supported by Erciyes University Scientific Research Unit with a project number of BAP-FCD-2015-5921. I express special thanks to Erciyes University scientific research unit employees for their help during the whole project. I gratefully thank to my friends Ümit Tayfun, Osman Yaslıtaş, Caner Durmuşoğlu and Ayşe Tuğba Kaya Deniz for their support, encouragement and friendship. x TABLE OF CONTENTS ABSTRACT ...................................................................................................................... v ÖZ ............................................................................................................................ vii ACKNOWLEDGEMENTS ............................................................................................. x TABLE OF CONTENTS ................................................................................................ xi LIST OF TABLES .........................................................................................................xiv TABLES .........................................................................................................................xiv LIST OF FIGURES ........................................................................................................ xv FIGURES ........................................................................................................................ xv ABBREVIATIONS .................................................................................................... xviii CHAPTERS 1.INTRODUCTION ......................................................................................................... 1 2.BACKGROUND INFORMATION ............................................................................. 5 2.1 Polyurethane ....................................................................................................... 5 2.1.1 Thermoplastic Polyurethane....................................................................... 7 2.2 Composites ....................................................................................................... 10 2.2.1 Production Methods of Polymer Composites ......................................... 10 2.3. Flammability of Polymers and Flame Retardants ......................................... 12 2.3.1 Polymers and Classification ..................................................................... 12 2.3.2 Burning Behaviour of Polymers .............................................................. 13 2.3.3 The Flame Retardancy Mechanisms of Polymers .................................. 17 2.4. Flame Retardant Additives ............................................................................. 20 2.4.1 Halogenated Flame Retardants ................................................................ 21 2.4.2 Phosphorus Containing Flame Retardants .............................................. 21 2.4.3 Mineral Flame Retardants ........................................................................ 22 xi 2.4.4 Inorganic Flame Retardants ..................................................................... 25 2.4.5 Intumescent Flame Retardants ................................................................. 26 2.6. Characterization Tests ..................................................................................... 29 2.6.1 Tensile Test ............................................................................................... 29 2.6.2 FTIR ........................................................................................................... 31 2.6.3 X-Ray Diffrection (XRD) ........................................................................ 32 2.6.4 Thermogravimetric Analysis (TGA) ....................................................... 33 2.6.5 Dynamic Mechanical Analysis (DMA) ................................................... 33 2.6.6 Scanning Electron Microscopy (SEM) .................................................... 34 2.7. Test Methods of Flammability Test Standards.............................................. 34 2.7.1 Cone Calorimeter Test .............................................................................. 35 2.7.2 UL 94 Test ................................................................................................. 39 2.7.3 LOI (Limited Oxygen Index) Test