Red clay composites reinforced with polymeric binders

Red clay/polymer composites were prepared by blending red clay with aqueous solutions of carboxymethyl cellulose (CMC), polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA). The effects of added polymer binders on properties such as compressive strength, flexural strength, water absorption, pore volume and specific surface area were investigated. Special attention was focused on two kinds of PVA: fully and partially hydrolyzed with varying degrees of polymerization. Red clay/polymer composites with 1.5 wt% PVA (F-24) showed the highest compressive strength (16.57 MPa), flexural strength (3.02 MPa) and better water-resistance. With increase in degree of saponification and degree of polymerization an increase in mechanical properties in red clay/PVA composites has been observed. Increasing concentration of polymer binder in red clay/PVA composites showed increasing water resistance with simultaneous decrease in pore volume. The present study concludes that PVA F-24 can be effectively used as binders in fabrication of bricks and tiles.