الفهرس 
STRUCTURE OF CELLULOSE FIBERSOnly 14 pages are availabe for public view
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Abstract
INTRODUCTION
1. Structure of ~~~~bers:
A wood fiber cell consists of primary wall, secondary wall
and the lumen or cell cavity. The fibers are cemented together
by non-cellulosic material known as middle lamella(l). In
higher plants, the primary wall in the form of a thin membrane
is called cuticle. The secondary wall represents the bulk of
cellulose substance paper, The fibers of cellulose may be regarded
as a two-phase system consisting of the same chemical
material which is arranged in two different types of physical
aggregation, with a meso-amorphous portion as a region of transition.
The cellulose chains in the crystalline region are
arranged strictly parallel, less so in the meso-amorphous portion
and more less in the amorphous region. The primary wall
is though consistedmainly of amorphous non-cellulosic constituents.
The major part of the crystalline cellulose exists in
the secondary wall which is built up of fibrils. The ratio of
crystalline to amorphous materials in cellulose fibers can be
determined by:-
1. Chemical method such as the difference in the rate of acid
hydrolysis and oxidation(Z).
2, Physical method such as x-ray analysis and density measurement.
In general, the results obtained by chemical method show
higher proportion of crystallinity than the physical method due
to the crystallization which takes place during the treatment(