STUDY OF ADHESION PROPERTIES OF NATURAL RUBBER, EPOXIDIZED NATURAL RUBBER, AND ETHYLENE-PROPYLENE DIENE TERPOLYMER-BASED ADHESIVES KWO HAN KIU UNIVERSITI SAINS MALAYSIA 2007 STUDY OF ADHESION PROPERTIES OF NATURAL RUBBER, EPOXIDIZED NATURAL RUBBER, AND ETHYLENE-PROPYLENE DIENE TERPOLYMER-BASED ADHESIVES by KWO HAN KIU Thesis submitted in fulfilment of the requirements for the Degree of Master of Science January 2007 ACKNOWLEDGEMENTS Heartiest thankful goes to Assoc. Prof. Dr. Poh Beng Teik since he agreed to become my very Supervisor for the lab work and tried to assist me in filling forms for pursuing the Degree of Master of Science. He had been providing me a lot of opportunities and flexibilities in viewing out my own ideas and most of them were supported by him. The guide that had given by him was remarkably useful and really helpful. He was never being selfish to view out his opinions for my guidance and he is definitely a sincere person. The fully spiritually support, love and care, and partially financial that had given by my family is gratefully acknowledged. The author has no reason for not to express his sincere gratitude to his parents for their encouragement between the course of this research and until the writing of this thesis. Lastly, the author shall thank Universiti Sains Malaysia (USM) for its wonderful study environment and beautiful landscape. Special thankful makes for Institute of Graduate Studies (IPS) and personnel for making this study possible through a postgraduate assistantship. The author at very last not forget to express his very last thankful to School of Industrial Technology, USM for providing him facilities and very much opportunities to work and co-operate with all staffs and lecturers. Thank you to you all for everything. May God bless you. TABLE OF CONTENTS Page Acknowledgements --------------------------------------------------------------------------- ii Table of Contents ------------------------------------------------------------------------------ iii List of Tables ------------------------------------------------------------------------------------ vii List of Schemes -------------------------------------------------------------------------------- ix List of Figures ---------------------------------------------------------------------------------- x List of Plates ------------------------------------------------------------------------------------ xiii List of Abbreviations/Symbols -------------------------------------------------------------- xiv Abstrak ------------------------------------------------------------------------------------------- xvi Abstract ------------------------------------------------------------------------------------------ xviii CHAPTER 1 – INTRODUCTION General ------------------------------------------------------------------------------------------ 1 CHAPTER 2 – LITERATURE SURVEY 2.1 Historical Background on Rubber ---------------------------------------------------- 5 2.2 Standard Malaysian Rubber (SMR) -------------------------------------------------- 7 2.3 Epoxidized Natural Rubber (ENR) --------------------------------------------------- 9 2.3.1 Epoxidation ------------------------------------------------------------------------- 13 2.3.1.1 In Situ Epoxidation ------------------------------------------------------- 13 2.3.1.2 ENR and Halogen -------------------------------------------------------- 17 2.4 Ethylene-Propylene Diene Terpolymer (EPDM) 2.4.1 EPDM Background ---------------------------------------------------------------- 19 2.4.2 EPDM --------------------------------------------------------------------------------- 20 2.4.3 EPDM in Tyres --------------------------------------------------------------------- 21 2.4.4 Tackifier in EPDM ------------------------------------------------------------------ 22 2.5 Coumarone-indene (CI) Resin -------------------------------------------------------- 23 2.6 Petroresin ---------------------------------------------------------------------------------- 25 2.7 Gum Rosin (Tricyclic Monocarboxylic Acids) -------------------------------------- 26 Page 2.8 Toluene (C7H8) ----------------------------------------------------------------------------- 26 2.9 Two-Roll Mill 2.9.1 Milling --------------------------------------------------------------------------------- 27 2.9.2 Two-Roll Mill in Laboratory ------------------------------------------------------ 28 2.10 Rotary Viscometer ---------------------------------------------------------------------- 30 2.11 Lloyd Adhesion Instruments ---------------------------------------------------------- 32 2.12 Texture Analyser ------------------------------------------------------------------------ 34 2.13 Adhesion ---------------------------------------------------------------------------------- 35 2.14 Pressure Sensitive Adhesive (PSA) 2.14.1 Rubber-Based PSA ----------------------------------------------------------- 36 2.14.2 Miscibility of Rubber-Based PSA ------------------------------------------ 40 2.15 Tackifying Resin 2.15.1 Resin Tackifier ------------------------------------------------------------------ 41 2.15.2 Resin Types --------------------------------------------------------------------- 44 2.15.3 Resin Tackifier in PSA -------------------------------------------------------- 46 2.15.4 Selection of Resin Tackifier ------------------------------------------------- 47 CHAPTER 3 – EXPERIMENTAL (MATERIAL AND METHODS) 3.1 Materials ------------------------------------------------------------------------------------ 49 3.2 Apparatus ---------------------------------------------------------------------------------- 52 3.3 Methods 3.3.1 Picking of Raw Material ---------------------------------------------------------- 57 3.3.2 Mastication -------------------------------------------------------------------------- 57 3.3.3 Adhesive Solution Preparation ------------------------------------------------- 59 3.3.4 Adhesive Coating ------------------------------------------------------------------ 61 3.3.5 Testing 3.3.5.1 Peel Test Modes ---------------------------------------------------------- 64 3.3.5.1.1 T-Peel Test ----------------------------------------------------- 65 Page 3.3.5.1.2 90o Peel Test -------------------------------------------------- 66 3.3.5.1.3 180o Peel Test ------------------------------------------------- 67 3.3.5.2 Tackiness Tests 3.3.5.2.1 Ball Rolling Tack Test --------------------------------------- 68 3.3.5.2.2 Viscosity Measurements ----------------------------------- 69 3.3.5.2.3 Loop Tack Test ------------------------------------------------ 70 3.3.5.3 Shear Resistance Test -------------------------------------------------- 71 CHAPTER 4 – EXPERIMENTAL RESULTS AND DISCUSSION 4.1 Cleavage of Raw Rubber Main Chain During Mastication --------------------- 73 4.2 Miscibility Between Coumarone-Indene (CI) Resin and Rubber-Based Adhesive Solution ---------------------------------------------------- 78 4.3 Viscosity of CI Resin Filled Rubber-Based Adhesive ---------------------------- 87 4.4 Tackiness of CI Resin Filled Rubber-Based Adhesive -------------------------- 89 4.5 Shear Resistance of CI Resin Filled Rubber-Based Adhesive ---------------- 99 4.6 Peel Strength of CI Resin Filled Rubber-Based Adhesive --------------------- 112 4.7 Advantages and Disadvantages of Rubber-Based Adhesive ----------------- 127 4.8 Effects of CI Resin, Petroresin and Gum Rosin on Viscosity of Rubber-Based Adhesive -------------------------------------------- 128 CHAPTER 5 – SUMMARY AND CONCLUSION -------------------------------------- 130 CHAPTER 6 – RECOMMENDATION FOR FUTURE RESEARCH --------------- 135 References -------------------------------------------------------------------------------------- 137 Appendices Appendix 1 – Equations ---------------------------------------------------------------------- 144 Appendix 2 – Data of Testing for SMR L-Based Adhesive (in Avg.) --------------- 148 Appendix 3 – Data of Testing for SMR 10-Based Adhesive (in Avg.) ------------- 151 Appendix 4 – Data of Testing for SMR 20-Based Adhesive (in Avg.) ------------- 154 Appendix 5 – Data of Testing for ENR 25-Based Adhesive (in Avg.) ------------- 157 Appendix 6 – Data of Testing for ENR 50-Based Adhesive (in Avg.) ------------- 160 Page Appendix 7 – Data of Testing for EPDM-Based Adhesive (in Avg.) --------------- 163 Appendix 8 – Selected Data for Tested Coumarone-Indene (CI) Resin Filled ENR 50 and EPDM-Based Adhesive Samples -------------- 166 Appendix 9 – Phase Homogeneity and Colour Comparison Between Coumarone-Indene (CI) Resin, Petroresin, and Gum Rosin Respectively Filled in SMR L, ENR 25 and ENR 50 Solution in the Beaker ------------------------- 170 Appendix 10 – Coumarone-Indene (CI) Resin, Petroresin, and Gum Rosin Before and After Pulverizing -------------------------------------------- 172 Publication List i. Peel Strength of ENR-Based Adhesive (Article for 3rd Life Sciences Postgraduate Conference, 24th – 27th May, 2006) ii. Peel and Shear Strength of Pressure-Sensitive Adhesives Prepared from Epoxidized Natural Rubber (Accepted for publication in J. Appl. Polym. Sci.; In press) LIST OF TABLES Page Table 2.1: 2 Factors, 2 Levels of Experiment on Effects of Elastomer and Resin Tackifier ------------------------------------------- 43 Table 3.1: Details of Main Materials and Chemicals Used ------------------------ 49 Table 3.2: Details of Apparatus and Machine for Lab Use ------------------------ 52 Table 3.3: Adhesive Formulation (Milled Rubber of Fixed