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.