| abstract |
A composition containing set plaster is described. In one aspect, the composition containing set plaster includes an interlaced matrix of the set plaster formed from at least calcined plaster, water, and an improvement material. The enhancement material may be selected from (i) an organic polyphosphonic compound, or a mixture thereof; (ii) a borate selected from ulexite, colemanite, or a mixture thereof; or a mixture of (i) and (ii). In another aspect, the composition containing set gypsum is treated with an enhancement material that can be selected from (i) an organic phosphonic compound, or a mixture thereof; (ii) a borate selected from ulexite, colemanite, or a mixture thereof; (iii) a carboxylic compound or a mixture thereof; or a mixture of (i), (ii) and / or (iii). The gypsum board has a buckling resistance (according to ASTM C473-95) of less than 0.254 cm by 0.61 m. of board length. The accelerator contains borate and an accelerator material that can be calcium sulfate. |