Soil stabilization by synthetic organic polymeric materials ismoderately a recent technique. The stabilizationmethod improve the many properties of soil structure, such as in swelling, flocculation,strength, aggregate stability, gradation, durability, reduce the plasticityindex and dispersion of soil clays 1.
Pavement subgrades are commonly designedon the expectation that specified levels of quality would be achieved for soillayer in the pavement system. A number of researchers have tried to make use ofdifferent types of polymeric binders for stabilizing soil in common and for erosioncontrol in particular. The use of synthetic organic polymers has gained global importanceduring the last few years and they have shown great potential for use as soiladditives to stabilize soil 2-3. The presence of organic groups such as synthetic polymers may modifythe interaction between the clay particles in soil because of polymer clay electrostaticinteraction. The nature of clay and polymer binding mechanisms is another partof important research.
Nonionic polymers are retained on based surfaces ofsilicates by hydrogen bonds formed between protic groups on the polymer andbasal oxygen of on siloxane (Si-O-Si) surface. Ionic interactions based chargeneutralization arises the positive charge (polycations) on the cationicpolymers through negative charge on the soil surface is the bonding mechanism.Anionic polymers tend to be repelled by the electro negatively charged soil surface,but adsorption can arise through the positive charged polyvalent cations 4-7.
Synthetic polymers carry ionic group along with polymer chain andbackbones. They may have positive charge (cationic) and negative charge (anionic).The most common copolymer is based on polyacrylamide (PAM) has been the focusof intense academic and industrial research because of their potential forapplication in subgrade stabilization, petroleum production, drag reduction,superabsorbent 8-9. The main scope of this research work is to improve the properties ofsoils with anionic and cationic polymeric materials.
Described here arethe syntheses of defined anionic and cationic PAM variants and thecorresponding results from tests with subgrade samples.