2001 Volume 8 Issue 293 Pages 268-274
Residual flexural strength of usual set plaster (CaSO4·2H2O) after the immersion in water for a day is lower than 50% of initial strength. In present study, the relationship between composition of polymer-gypsum composite and water-resistivity of resulting composite material was investigated.
After several attempts, we succeeded to prepare highly water-resistant polymer-gypsum composite starting from the mixture of gypsum, resorcinol, formalin, methanol and catalytic amount of acid.; residual flexural strength of present composite after immersion in water at room temperature for 84 days kept about 95% of initial strength and increased to approximately 140% of the initial strength when it was air-dried at 30°C for 24h.
