CHAPTER 1
INTRODUCTION
The new developments o f science that have taken place in most countries a ll over the world, are awakening to the re a liz a tio n of the thorough techniques. Such techniques arise and evolve out o f a m u lti
p lic ity of decision in in d u s trie s . The most v o la tile technology of the present in d u s tria l age is based on chemical transform ation which is applicable to the form ation of new chemical compounds or in d u s tria l products derived from a large number of raw m aterials. Among those raw m aterials, cellulose is one th a t plays an im portant ro le not only in industry but also th e o re tica l chem istry. One achievement o f chemical transform ation of cellulose involves a chemical reaction called
"E th e riii^ a tio n ". However, ce llu lo se alone does not react w ith e th e ri- fyin g agent ( 1 ).
NOl-i C'l ! I ----i
i (If>
! CHOi
I ju M น;Æ \
แ CN
> JÔ1
fHjCH ; H OMOt-!
&
CHp*
( I )
structure of C ellulose (ท = 25 - 250)
C ellulose (1) is a n atural carbohydrate. I t is a high polymer
2
>
consisting of 1, 4 - anhydro - p - glucose u n its joined by an oxygen linkage to form long and e sse n tia lly lin e a r m olecular chains (2). In each glucose u n it, there are three hydroxyl groups at 2-, 3-J and 6- p o sitio n s. According to Denharr. and Woodhouse, the chemical transforma
tio n o f cellulose by s u b s titu tio n can generally occur only at these three hydroxyl positions (3). The various hydroxyl groups have d iffe re n t
re a c tiv itie s w ith respect to a lk a li (4). Cellulose which is subjected to a lk a li treatment is called "a lk a li c e llu lo s e ". A lk a li ce llulose is considered to be an im portant interm ediate product in the preparation of ce rta in cellulose derivatives as pointed out by N .I. N ik itin (4).
As previously mentioned, cellulose alone does not react w ith e th e rify in g agent. A lk a li cellulose is so fa r believed to be an in te r
mediate in e th e rific a tio n fo r most chemical transform ations o f ce llu lo se . Though the a lk a li treatment of ce llu lo se has been in te n s iv e ly in v e s ti
gated fo r years, i t has not been completely c la rifie d . I t is , however, cle a r that sodium hydroxide is frequently used in a lk a li treatm ent.
Sodium ions may impart the effectiveness of the chemical transform ation of cellulose especially in e th e rific a tio n . Therefore, the present work is concerned w ith a study of the re a c tiv ity of sodium ions in e th e ri
fic a tio n reaction of ce llu lo se .
