Untilnow, polymer-polymer miscibility has been treated as a special in the field ofpolymer blends or alloys; 1 this subject is vast and has been thefocus of much work both theoretical and experimental. 2 Polymerblends are physical mixtures of structurally different polymers or co-polymer,which interact through secondary forces with no covalent bonding that aremiscibility at molecular level.3,4 The basis of polymer-polymermiscibility may arise from any specific interaction, such as hydrogen bonding,dipole-dipole forces and charges transfer complexes for homopolymer mixture.4,5,6,7There have been various techniques of studying the miscibility of the polymerblends.
4,9,12 Most polymers Pairs are immiscible and separate intothe phase systems. If they are very immiscible, the domain size is coarse,irregular and unstable, and the in face is sharp and week, giving poorproperties and practical incompatibility. When a two-phase blend has naturallygood properties and practical compatibility, the reason is usually to be soughtin practical miscibility.13 It is desirable to identify simple,low cost and rapid techniques to study the miscibility of polymer blends.
Chee14and Sun, Wang & Fung15 have suggested a viscometric insolution.14,15 Singh and Singh have suggested the use ofultrasonic velocity & viscosity measurements for investigating the polymermiscibility in solution.16,17 Palladhi and Singh have shown thevariation of ultrasonic velocity and viscosity with blend composition is linearfor miscible blends and non-linear for immiscible blends.18,19Varada Rajulu, Reddy, and Ranga Reddy (1998) have used ultrasonic andrefractometric technique to study the miscibility of polymer blends.20Water soluble polymer have a wide range of industrial application like food, pharmaceutical,paints, textiles, paper construction, adhesion, coating, water treatment etc.21Hydroxypropyl methyl cellulose (HPMC) is a polysaccharide prepared fromcellulose. 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, whichoffers good tensile strength (TS), flexibility and barrier properties to oxygenand aroma.4 PVA shows a high degree of swelling in water (orbiological fluids) and a rubbery and elastic nature and therefore closelysimulates natural tissue and can be readily accepted into the body. PVA ismainly used in topical pharmaceutical and ophthalmic formulation.
21GrapheneOxide (GO) is a water soluble nano-material prepared through extensive chemicalattack of graphite crystals to introduce oxygen containing defects in thegraphite stack.22 GO is an oxidized Graphene sheet having itsbasal planes decorated mostly with epoxide and hydroxyl groups, in addition tocarbonyl and carboxyl group located at the edges.23 The mostcommon approach to graphite exfoliation is the use of strong oxidizing agentsto field Graphene Oxide (GO), a non conductive hydrophilic carbon material.24ChemicalModified Graphene (CMG) has been studied in the context of many applicationssuch as polymer composities, energy-related materials, sensors, paper-likematerials, field-effect transistors (FET), and biomedical, due to its excellentelectrical, mechanical and thermal properties.25 The most commonsource of graphite used for chemical reactions, including its oxidation, isflake graphite, which is a naturally occurring mineral that is purified toremove heteroatomic contamination.
GO prepared from flake graphite can bereadily dispersed in water and has been on a large scale or preparing largegraphitic films.24Despitethe subetantial interest and effort in utilizing GO as dispersants, to the bestof our knowledge, there is no work specifically dedicated to the usage of GOfor compatibilizing immiscible polymer blends, which appears to be of morepractical significance in that it can fully exploit the extraordinaryproperties of their appeating carbon nano materials.