Until used in the preparation of controlled release

Until
now, polymer-polymer miscibility has been treated as a special in the field of
polymer blends or alloys; 1 this subject is vast and has been the
focus of much work both theoretical and experimental. 2 Polymer
blends are physical mixtures of structurally different polymers or co-polymer,
which interact through secondary forces with no covalent bonding that are
miscibility at molecular level.3,4 The basis of polymer-polymer
miscibility may arise from any specific interaction, such as hydrogen bonding,
dipole-dipole forces and charges transfer complexes for homopolymer mixture.4,5,6,7
There have been various techniques of studying the miscibility of the polymer
blends.4,9,12 Most polymers Pairs are immiscible and separate into
the phase systems. If they are very immiscible, the domain size is coarse,
irregular and unstable, and the in face is sharp and week, giving poor
properties and practical incompatibility. When a two-phase blend has naturally
good properties and practical compatibility, the reason is usually to be sought
in practical miscibility.13 It is desirable to identify simple,
low cost and rapid techniques to study the miscibility of polymer blends. Chee14
and Sun, Wang & Fung15 have suggested a viscometric in
solution.14,15 Singh and Singh have suggested the use of
ultrasonic velocity & viscosity measurements for investigating the polymer
miscibility in solution.16,17 Palladhi and Singh have shown the
variation of ultrasonic velocity and viscosity with blend composition is linear
for miscible blends and non-linear for immiscible blends.18,19
Varada Rajulu, Reddy, and Ranga Reddy (1998) have used ultrasonic and
refractometric technique to study the miscibility of polymer blends.20
Water soluble polymer have a wide range of industrial application like food, pharmaceutical,
paints, textiles, paper construction, adhesion, coating, water treatment etc.21
Hydroxypropyl methyl cellulose (HPMC) is a polysaccharide prepared from
cellulose. It is mainly used in the preparation of controlled release tablets.
It contains both methyl and Hydroxypropyl substitutes. Polyvinyl Alcohol (PVA)
is a synthetic water-soluble polymer with good film forming property, which
offers good tensile strength (TS), flexibility and barrier properties to oxygen
and aroma.4 PVA shows a high degree of swelling in water (or
biological fluids) and a rubbery and elastic nature and therefore closely
simulates natural tissue and can be readily accepted into the body. PVA is
mainly used in topical pharmaceutical and ophthalmic formulation.21

Graphene
Oxide (GO) is a water soluble nano-material prepared through extensive chemical
attack of graphite crystals to introduce oxygen containing defects in the
graphite stack.22 GO is an oxidized Graphene sheet having its
basal planes decorated mostly with epoxide and hydroxyl groups, in addition to
carbonyl and carboxyl group located at the edges.23 The most
common approach to graphite exfoliation is the use of strong oxidizing agents
to field Graphene Oxide (GO), a non conductive hydrophilic carbon material.24

Chemical
Modified Graphene (CMG) has been studied in the context of many applications
such as polymer composities, energy-related materials, sensors, paper-like
materials, field-effect transistors (FET), and biomedical, due to its excellent
electrical, mechanical and thermal properties.25 The most common
source of graphite used for chemical reactions, including its oxidation, is
flake graphite, which is a naturally occurring mineral that is purified to
remove heteroatomic contamination. GO prepared from flake graphite can be
readily dispersed in water and has been on a large scale or preparing large
graphitic films.24

Despite
the subetantial interest and effort in utilizing GO as dispersants, to the best
of our knowledge, there is no work specifically dedicated to the usage of GO
for compatibilizing immiscible polymer blends, which appears to be of more
practical significance in that it can fully exploit the extraordinary
properties of their appeating carbon nano materials.