OB A STUDY OF INDIGENOUS DYE PRODUCING PLANTS AND THEIR DERIVATIVES IN TEXTILE DYEING ^ OF MORATUWA, I MORATUWA 6 7 7 W K.P.N. GUNARATNE This thesis was submitted to the Department of Textile and Clothing Technology of the University of Moratuwa in partial fulfilment of the requirements for the Degree of Master of Science Department of Textile and Clothing Technology University of Moratuwa Sri Lanka May 2004 University of Moratuwa Thesis c-f - S I 0 4 9 - . , 8 I 0 4 ' "I certify that this thesis does not incorporate with acknowledgment any material previously submitted for a degree or diploma in any university and to the best of my knowledge and belief it does not contain any material previously published or orally communicated by another person expect where due reference is made in the text." K.P.N. Gunaratne (Candidate) "To best of my knowledge the above particulars are correct." II ABSTRACT With the discovery of synthetic dyes all colour industries, not only textile industry had turned to the more economical, reproducible, high colour fast and easy to use synthetic dyes and abandoned the natural dyeing tradition which had prevailed as the only colouring technology till then. But recently a revival in the natural dyeing technology has occurred as solutions to the environmental pollution arising out of the wet processing of textiles as well as to the growing trend of dye toxicity and allergies to the textile consumers. Natural dyes provide not only a good alternative to the environmental pollution arising from synthetic dyes but also provide low toxicity and allergic reactions while giving unique and fascinating colours which are not achievable from synthetic dyes. A thorough review to the historic background of the origin and progression of natural dyeing techniques in the world with specific concern to Sri Lanka was carried out. During this review a search was also made into the reasons for the erosion of this valuable tradition of natural dyeing. Through a survey of the natural dye producing plants world over, a list of indigenous dye producing plants in Sri Lanka was prepared and investigated the possibility of using one of these plant sources to develop a new natural dye based on its extraction. In selection of this plant source the major concern was given to the fact that it should be abundant as a waste material in Sri Lanka. Black tea, which is highly available as a waste (dust) from tea factories and domestic sources (brewed tea) were used to extract polyphenols, which are an abundant form of natural compounds in tea. These were used as the coupling component to produce azo compounds by coupling with different diazonium salts. Both polyphenols and azo compounds were separated and solidified and thus obtained azo compounds had variable colour shades depending on their respective diazonium salts. The possibility of applying these azo compounds as in-situ azo dyes on 100% cotton and ready-made insoluble disperse azo dyes using HTHP conditions on 100% polyester, 100% nylon and 100% wool were investigated. Different azo compounds produced different colour shades on different fabric types as well as on the same fabric type. Optimisation of dye bath conditions to improve the take up of polyphenols by cotton using the in-situ III application of azo dyes was also carried out. The colours produced on cotton were not very bright and showed moderate colour fastness to washing, good colour fastness to rubbing while the brilliant colours produced on polyester showed good to very good wash, rub and sublimation fastness, after reduction clearing. The colour depth and fastness on nylon and wool were better than those on polyester. The light fastness of all the azo dyed samples was poor and should be improved using suitable after treatments. The percentage yield of polyphenols for both used and unused black tea leaves and the percentage yield of different azo compounds obtained from unused black tea leaves were calculated. The study was basically carried out with the aim of investigating the traditional dyeing techniques and indigenous dye producing plant sources in Sri Lanka and to assess the possibility of using polyphenols from one of the selected plant resources. Tea, which is abundantly available as tea waste (dust) from factories and brewed tea leaves from domestic sources was selected as the natural source of dye or dye intermediate for textile dyeing. IV ACKNOWLEDGEMENT It is with immense gratitude and honour that I appreciate the invaluable service of my two supervisors Mrs. Samudrika Wijayapala and Mr. N.G.H. de Silva for their guidance, support, encouragement and advice offered to me right through out this research study. I would like to thank Prof. Lakdas Fernando, Dr. Lanarolle and Dr. Nirmali de Silva for their vital presence and contributions in the progress review committees and the valuable guidance and suggestions provided to make this study a success. I would like to thank Mr. D.P.D. Dissanayake for his support and advice as the M.Sc. course co­ ordinator. I sincerely thank all the staff members of the Department of Textile and Clothing Technology of University of Moratuwa for offering their helping hands to complete this research study successfully. I would like to offer special thanks to technical officers Mr. C P . Malalanayake and Mrs. P. Wanniarachchi, and the lab attendant Mr. W. Chandradasa for their co-operation extended to me during my work. I would like to thank the environmental laboratory staff of Department of Civil Engineering, especially Ms. Priyanka Dissanayake for the enormous support given me to complete the experimental part of this research. I wish to extend my sincere thanks to Ms. U.G. Chandrika (Senior lecturer at the University of Sri Jayawardanapura) and Mr. M.J.N. Muthunayake (Textile Technologist at the Department of Textiles) for their guidance and support given in the initial stages of this research, without which this research would have not been a success. I would like to thank the library staff of the National Museum, Industrial Technology Institute, University of Moratuwa, University of Sri Jayawardanapura, University of Indigenous Medicine and the Public Library of Colombo for their tremendous support V in finding the literature for the study, which would have been even difficult without their committed service. My special thanks go to my colleague Dumini Pathirana, my husband Manoj Suraweera and my family for sharing my difficulties and successes and being there to lift my spirits up right throughout the course of this research study. Finally, it is my duty to extend my grateful acknowledgement to the Asian Development Bank, Science and Technology Personnel Development Project for the financial assistance that enabled me to undertake a research project leading to Masters Degree. VI TABLE OF CONTENTS Page CHAPTER ONE -INTRODUCTION 1 1.1 History of Textile Colouration 1 1.2 Textile Colourants 5 1.2.1 Requirements of a Textile Dye 6 •f 1.2.2 Chemical Basis of Textile Colouration 6 1.2.3 Classification of Textile Colourants 7 1.3 Textile Dye Industry Today 10 1.4 Environmental Aspects of Textile Dyestuff Manufacturing 10 1.5 Natural Dyes 13 1.5.1 Classification of Natural Dyes 14 1.5.2 Why have Natural Dyes Subsided? 17 1.5.3 Why Natural dyes Again? 18 1.5.4 Why Indigenous Plants? 19 1.5.5 Limitations of Natural Dyes 19 1.5.6 Advantages of Natural Dyes over Synthetic Dyes 20 ^ 1.5.7 Extraction Methods of Natural Dyes 20 1.6 Natural Dyes and Dyeing Practices in Sri Lanka 21 1.7 Objective 24 1.8 Scope 26 CHAPTER TWO - MATERIALS AND METHODOLOGY 30 2.1 Indigenous Dye Producing Plants and Traditional Dyeing Techniques of 30 Sri Lanka 2.1.1 Indigenous Dye Producing Plants of Sri Lanka 30 2.1.2 Traditional Dyeing Techniques of Sri Lanka 30 2.2 Investigation of a New Dye Material 30 2.3 Selection of a Plant Source 31 2.3.1 Literature Survey 31 2.3.2 Preliminary Trials 32 2.4 Extraction of Polyphenols from Tea 33 VII 2.5 Solidification of Polyphenols 34 2.6 Azo Dye Preparation 36 2.6.1 Preparation of the Coupling Component 36 2.6.2 Preparation of the Diazonium Salt 36 2.6.3 Coupling of Diazonium Salt with the Coupling Component 36 2.7 Application to Fabrics 37 2.7.1 Ready Made Azo Dye Applications 37 2.7.2 In-Situ Azo Dye Application on Cotton 38 2.8 Take Up of the Coupling Component by Cotton 38 2.8.1 The Effects of Different Dye Bath Conditions on the Up Take of 39 Polyphenols by Cotton 2.8.1.1 Using an Electrolyte 3 9 2.8.1.2 Using a wetting agent 3 9 2.8.1.3 Raising the temperature 40 2.8.1.4 Varying the M L R . Value 40 2.8.1.5 Different pH Conditions 40 2.8.2 Optimization of the Conditions Affecting the Take Up of 40 Polyphenols 2.9 Effect of Different Diazonium Salts 41 2.10 Colour Fastness Testing 41 2.11 Product Yield 42 CHAPTER THREE - RESULTS AND DISCUSSION 43 3.1 Indigenous Dye Producing Plants and Traditional Dyeing Techniques of 43 Sri Lanka 3.1.1 Indigenous Dye Producing Plants of Sri Lanka 43 3.1.2 Traditional Dyeing Techniques of Sri Lanka 47 3.2 Selection of the Plant Source 48 3.2.1 Literature Survey 48 3.2.2 Preliminary Trials 52 3.3 Extraction and Extractability of Polyphenols from Tea 53 3.4 Solidification of tea polyphenols 54 3.5 Azo Dye Preparation 54 3.6 Application to Fabrics 54 3.7 Take Up of the Coupling Component by Cotton Fabrics 57 3.7.1 The Effects of Different dye Bath Conditions on the Up Take of 57 Polyphenols by Cotton VIII 3.7.2 Optimisation of the Conditions Affecting the Take Up of 59 Polyphenols by Cotton 3.8 Effect of Different Diazonium Salts 60 3.9 Colour Fastness Testing 66 3.10 Product Yield 71 CHAPTER FOUR - CONCLUSIONS AND FUTURE WORK 73 4.1 Conclusions 73 4.2 Future Work 76 REFERENCES 77 IX LIST OF FIGURES Figure No. Title 1.1 Classification of Textile Colourants 2.1 Outline of Extraction, Solidification and Separation of Polyphenols from Tea Leaves 2.2 Outline of Extraction and Development of Dye Materials from Tea Leaves and Their Application on Fabrics 3.1 . Structures of Black Tea Polyphenols 3.2 Structures of Green Tea Polyphenols 3.3 Cotton Samples Dyed with Different Methods Using Tea Polyphenols 3.4 Fabric samples Dyed with Azo Dye Prepared with Tea Polyphenols and Aniline Diazonium Salt 3.5 Fabric samples Dyed with Ready Made Azo Dye Prepared with Tea Polyphenols and Aniline Diazonium Salt 3.6 Effect of Dye Bath pH on Dyeing of Cotton and Jute with Tea 3.7 Visible spectrum of A1 3.8 Visible spectrum of A2 3.9 Visible spectrum of A3 \ ., ^ 3.10 Visible spectrum of A4 3.11 Visible Spectrum of Tea Polyphenols 3.12 Colour Shades Produced by In-situ azo Dyes on Cotton X LIST OF TABLES Table No. Title 1.1 World Dyestuff Usage 1992 1.2 Estimated Annual Consumption of Cellulosic Dyes 4 1.3 Tolerance Limits for Effluents from Textile Industry Discharged into Inland Surface Waters 1.4 Number of Natural Dyes for Different Hues 1.5 Carcinogenic Amines Banned by the German MAK Commission 2.1 Selected Plants and Their Parts Used for Polyphenol Extraction 2.2 Optimisation of Conditions for the Improvement of Dye Up Take in Dyeing Cotton Using Azo Dyes prepared from tea extract 3.1 Dye Producing Plants Indigenous to Sri Lanka 3.2 The Effects of Electrolyte, Wetting Agent and M.L.R. Values on the Dye Take Up by Cotton 3.3 Designations and Colour Shades of Azo Compounds Prepared with Tea Polyphenols 3.4 Colour Shades of Azo Compounds on Fabrics 3.5 Colour Fastness Ratings for Cotton Dyed with Different In-situ Azo Compounds Prepared by Impregnation in Alkaline ^ Conditions 3.6 Colour Fastness Ratings for Cotton Dyed with Different In-situ Azo Compounds Prepared by Impregnation in Acidic Conditions 3.7 ISO Colour Fastness Ratings for Polyester Fabrics Dyed with Al XI ISO Colour Fastness Ratings for Polyester Fabrics Dyed with Different Azo Compounds ISO Colour Fastness ratings for Nylon and Wool Dyed with Different Azo Compounds Percentage Yields of Extractable Polyphenols from Different Types of Tea Leaves Percentage Yields of Different Azo Compounds Prepared from Unused Black Tea Leaves XII