Chemical Investigations on Lac and Its Derived Products

Abstract

Allah, the Almighty has created each and everything in this universe. There are creatures, most negligible in shape and size that has tremendous importance. One of such a creature is !~c inse~t1 Ke_rrig_ lacca. Its size is 0.35 mm but its importance considering industrial value is of magnificent nature. Its resinous secretion obtained on the branches of some selected host plants is of vital industrial importance in many fields and is benefiting the human beings. This secretion from the glands of the lac insect is called lac. This is one of Allah's Qudrat that such a small insect (creature) can produce a widely applicable secretion, the lac. Hence a piece of research work in this field is unde1iaken in order to investigate the properties of different lac products and to study the chemistry of lac. In the beginning of the thesis is given a General Introduction comprising of the origin and history of lac, lac production in Bangladesh etc. For convenience of presentation, the experimental work has been divided into four small chapters. Each chapter is complete within itself and has been written in the conventional fonn of a paper. Effort has been made for literature coverage upto dclte. The thesis is appended with a list of paper and also reprint of publications. I express my sincere gratitude and indebtedness to my respected teachers, Dr. M. Umar Ali, Professor, Department of Chemistry, Rajshahi University, Rajshahi and Dr. M. Omar Faruq, Director (Retd), Bangladesh Council of Scientific and Industrial Research (BCSIR) Laboratories, Rajshahi for their keen interests and valuable inspiring and indespensable guidance throughout the course of these studies and preparation of this thesis. I am very much grateful to Dr. M. Yusuff Ali, Ex-Vice Chancellor, Rajshahi University, Professor, Department of Chemistry, Rajshahi University, Rajshahi for his inspiration and encouragement during the study period. I am also grateful to Professor M.A . .lalil Miah, Chairman, Department of Chemistry, along with other professors of this department, Rajshahi University, Rajshahi for providing necessary facilities, inspiration and helpful advise. My sincere thanks are due to Dr. M. Rezaul Karim, Chainnan, Department of Bio-Chemistry, Rajshahi University, Rajshahi for providing necessary facilities 111 testing antibacterial activities of the synthesised products. My thanks are also extended to Dr. M. Golbar Hossain, Director, BCSIR Laboratories, Rajshahi for his cooperation and encouragement during the course of the study. I also take the opportunity to express my thanks to Mr. M. Ismail Hussain Khan, Senior Scientific Officer (Retd) BCSlR Laboratories, Rajshahi for his many fruitful discussions. I wish to express my thankfulness to the authority, BCSIR, Dhaka and Ministry of Sceince & Technology, Government of Bangladesh for the award of scholarship under Human Resource Development Programme (HRDP) and also for granting me study leave with fu1l pay for Ph.D. Programme. I am thankful to Mr. Akram Hossain, Department of Chemistry, Dhaka University, Dhaka for recording IR spectra of my research samples. I have no hesitation to express my gratefulness to my friends, M. Maksud Ali, M. Siddiqur Rahman, M. Abdul Hye and M. Rafiquzzaman for their occasional help during this work at the Laboratories. Thanks are also due to my colleagues, Mr. Ranajit Kumar Sarker, M. Mesbahul Alam, M. Azizur Ralunan, Mrs. Seatara Khatun, Mrs. G.R.M. Astaq Mohal Khan, M. Lutfor Ralunan, .M. Mostafizur Ralunan and M. Kobad Hossain for their cooperation throughout the progress of the work. I am thankful to Md. Shahazada, B.T.S. Commercial Institute for his sincere type setting. I express my heartiest gratitude to my parents who brought me up and opened my eyes of lrnowledge. Finally, I acknowledge with great pleasure the good wishes and cooperation of my other research co1leagues, friends and all other relations.