STUDY OF CARDANOL AS ANTIOXIDANT IN TRUCK TYRE TREAD IN PLACE OF TMQ A REPORT ON THE PROJECT WORK Carried out At APOLLO TYRES LIMITED PERAMBRA By Samson David Department of Polymer Science & Rubber Technology Cochin University of Science & Technology Cochin 682022 2007 th 11 May2007 TO WHOMSOEVER IT MAY CONCERN This is to certify that Mr. SAMSON DAVID B-Tech. 8th semester Polymer Science and Rubber Technology student of Cochin University of Science and Technology, Kochi, have successfully completed his factory training under the guidance of the undersigned, during the period from 8th January to 21st February 2007. Mr. SAMSON DAVID showed good inquisitiveness and keenness in carrying out his project work successfully and I take this opportunity to wish him all the best. For APOLLO TYRES LTD th 12 May2007 TO WHOMSOEVER IT MAY CONCERN This is to certify that Mr. SAMSON DAVID B-Tech. 8th semester Polymer Science and Rubber Technology student of Cochin University of Science and Technology, Kochi, have successfully completed the project on “EFFECT OF CARDANOL AS ANTIOXIDANT IN TRUCK TYRE TREAD INSTEAD OF TMQ” under the guidance of the undersigned, during the period from 21st February 2007 to 11th May 2007. Mr. SAMSON DAVID showed good inquisitiveness and keenness in carrying out his project work successfully and I take this opportunity to wish him all the best. For APOLLO TYRES LTD My debts of gratitude………… We thank almighty God for showering grace up on us, without his blessings we would not have achieved my goal. Whenever we started feeling low, He would fill us with new hope and determination. It is my privilege to place on record my gratitude to Dr. Thomas Kurian, Head of the department of polymer Science and Rubber technology, CUSAT Kochi, for granting me permission to work on this interesting project at Apollo Tyres, Perambra. His encouragement and support were invaluable for the completion of this project. It is great pleasure to express my sincere gratitude to my Project Guide, Mr. K. A. Chacko, who was with me through every phase of this project with out whose perseverance this would not have achieved what it has today. He was always kind and patient to me in clearing my doubts and his knowledge in Tyre Technology invariably saved me from pouring over large volume of information. I express my sincere thanks to Dr. Eby Thomas Thachil, Mrs. Mary Alexander and all faculty members of the Dept. of Polymer science and Rubber Technology for their timely advices and constant help throughout the project work. I would like to express my profound gratitude to Mr. George Varghese, Technical Head, for his timely help and valuable suggestions about Rubber compounding. Our thanks goes to Mrs. C. L. Santha, Laboratory, Apollo Tyres, and other laboratory personnel, for their valuable help in finishing this project work. I thank all my friends at CUSAT Kalamassery, for extending their help in every possible way. Last but not least I would like to thank my dear classmates and family for their moral support. SSaammssoonn DDaavviidd C O N T E N T S SL NO TITLE PAGES 01 INTRODUCTION 1 02 CARDANOL AS ANTIOXIDANT 18 03 COMMON RUBBER ANTIOXIDANT TYPES 24 04 SCOPE OF THE WORK 28 05 EXPERIMENTAL TECHNIQUES 29 06 RAW MATERIAL USED FOR EXPERIMENT 30 07 EXPERIMENTAL PROCEDURES 35 08 EXPERIMENTAL COMPARISON 48 09 GRAPHS 57 10 RESULTS AND DISCUSSIONS 67 11 SUMMARY AND CONCLUSIONS 70 12 APPENDIX-1 71 13 APPENDIX -2 74 14 APPENDIX -3 76 15 REFERENCE 77 Introduction Study of Cardanol as Anti oxidant in Truck Tyre Tread inplace of TMQ 1. INTRODUCTION The technological performance of various types of rubber depends on their ability to withstand the effects of the service environment. The development of rubber for many modern uses would not have been possible without the discovery of chemicals to prevent their degradation during service. The deterioration in the useful properties of rubber products with time is a serious problem involving the oxidation of polymers by the oxygen of the atmosphere. Natural and synthetic polymers deteriorate on ageing in varying degrees as a result of the combination of a number of factors like heat, light, oxygen and ozone. The irreversible nature of the oxidative processes to which industrial polymers are subjected during high temperature processing and under aggressive conditions during service has intensified the search for improved stabilizing systems. This has resulted in the development of Antioxidants, Anti-fatigue agents, Melt stabilizers, UV-stabilizers and Fire retardants. Antioxidants - Historical Background Natural rubber latex contains a small percentage of non-rubbery materials, which function as antioxidants. These materials effectively protect the rubber during coagulation and storage, but they are destroyed during the processing and curing operations. Thus, it is not surprising that the earliest manufacturers of rubber products, who knew nothing of oxidation, were plagued by the problem of deterioration. Hofmann in 1861 was credited with being the first to discover the oxygen absorption involved in this degradation, and the first patent, concerned with the use of phenol and cresol as antioxidants was issued to Murphy in 1870.Until about 1910 the materials chosen to reduce this oxidative degradation were natural products, such as coal tar resins, coumarone resins, paraffin, creosote and inorganic and organic reducing agents. Department of Polymer Science and Rubber Technology, CUSAT 1 Study of Cardanol as Anti oxidant in Truck Tyre Tread inplace of TMQ The stability of the rubber product was not greatly improved when these additives were used. The first antioxidants made their appearance in 1924 and slowly gained acceptance. Within a few years, their true value in rubber industry became apparent and the resulting search for new antioxidants led to the patenting of hundreds of materials. The first two widely used antioxidants were the reaction product of aniline and acetaldehyde and aldol naphthylamine. Hydroquinone and pyrogallol were patented in1901, resorcinol and 2-naphthol in 1920, 1- naphthol and aldehyde condensation products in1922, and mercaptobenzimidazole in 1931. In 1957, a new way to manufacture 2,6-di-terf- butylphenol in high yield and purity was discovered. The attachment of methylene bridged groups to the para position of this phenol by condensation reactions with formaldehyde and acrylates led to the discovery and commercialization of a number of new antioxidants. Currently, bound antioxidants are being developed to give maximum resistance to losses by extraction and volatilization. General Aspects of Polymer Degradation and Stabilization All hydrocarbons are vulnerable to deterioration caused by heat, light and oxygen. These polymers vary widely in their susceptibility to oxidative degradation. It is well-known that the relationship between polymer structure and ease of oxidation depends primarily on the relative C-H bond dissociation energies of the various polymers. Polymers with C-H bonds of low dissociation energies are more readily oxidized than polymers with higher C-H bond dissociation energies. Consequently, branching and un-saturation lower bond energies and increase the polymer's susceptibility to oxidation. The amount of un-saturation present in a polymer is also important. The rubber with low olefinic content, such as EPDM (ethylene propylene diene terpolymer), is more resistant to oxidation than the highly unsaturated rubbers, such as SBR (styrene Department of Polymer Science and Rubber Technology, CUSAT 2 Study of Cardanol as Anti oxidant in Truck Tyre Tread inplace of TMQ - butadiene rubber) and NR (natural rubber). The chemical structure of the polymer not only determines the rate of oxidation but also the physical changes that can occur during oxidation. Hardening of the polymer occurs when oxidative crosslinking pre-dominates in the degradation process. Most rubbers, such as SBR, NBR (nitrile-butadiene rubber) and BR (cis-polybutadiene) harden during oxidation, while rubbers derived from isoprene, such as NR, IR (cis-polyisoprene) and IIR (isobutylene isoprene rubber), soften on oxidation due to chain scission. It is not surprising, then, that an antioxidant which affords excellent protection in one rubber is not the most effective stabilizer for another. A broad distinction is generally made between materials, which can protect raw synthetic rubber, and those, which protect vulcanized rubber products. Synthetic rubbers are very susceptible to oxidation and must be protected with an antioxidant immediately after they are formed by polymerization in order to prevent oxidative degradation during the high temperature drying step and during the subsequent storage. Tyres account for the largest volume of antioxidants used each year; they are primarily the amine staining antioxidants. A wide variety of light coloured vulcanized products are protected with non-staining antioxidants. Mechanism of polymer oxidation Oxidation of polymers can lead to chain scission, crosslinking or formation of oxygen containing functional groups in the polymer or its degradation products. In order to understand the antioxidant inhibition mechanisms, a brief outline of the oxidation process is given below. Department of Polymer Science and Rubber Technology, CUSAT 3 Study of Cardanol as Anti oxidant in Truck Tyre Tread inplace of TMQ Initiation RH = polymer molecule or portion thereof, AH = antioxidant, A =antioxidant radical, RO =polymer peroxy radical, and 2 ROOH = polymer peroxide. Basic classification of antioxidants Rubber antidegradants included in this classification are divided into six classes as shown below. The classification in general is based on chemical structure and application on rubber. a) Class 1. p-Phenylene diamines (PPDs) - This group of additives represents the primary materials used in tyres and other mechanical goods to Department of Polymer Science and Rubber Technology, CUSAT 4 Study of Cardanol as Anti oxidant in Truck Tyre Tread inplace of TMQ impart ozone protection. These additives are also used as antioxidants and antiflex agents in a number of applications but are considered to be strongly staining and thus limited to black rubber applications. They can also be used as raw polymer stabilizers. b) Class 2. Trimethyl-diquinolines (TMQs) - These materials are primarily used to protect rubber articles from degradation by atmospheric oxygen at higher temperatures. They are moderately staining. c) Class 3. Phenolics - Phenolic antidegradants represent a group of nonstaining and non discoloring additives used primarily in light colored mechanical goods and tyres. They can also be employed as raw polymer stabilisers. In general they are weaker antioxidants than amine types. d) Class 4. Alkylated diphenylamines (DPAs) - This class of additives generally represents substituted amine antioxidants and it is used as raw polymer stabiliser in vulcanizate applications. These additives are moderately discoloring and staining. e) Class 5. Aromatic phosphites - These are phosphorus containing fully non-staining, non-discoloring additives used as stabilzers for synthetic elastomers in 'white rubber' applications. They also have applications as peroxide decomposers and radical traps in polymer systems. f) Class 6. Diphenylamine - ketone condensates - This group of additives is used primarily in carbon black loaded compounds to protect them against oxygen and heat deterioration. Classification of antioxidants based on their mode of action Two main groups of antioxidants are distinguished according to their mode of action: primary or chain breaking, and secondary or preventive antioxidants. Chain breaking antioxidants Chain breaking antioxidants interfere with the chain propagation steps of Department of Polymer Science and Rubber Technology, CUSAT 5