| abstract |
A lightweight gypsum wallboard having a foamed gypsum core reinforced with pre-gelatinized, e.g., pre-gelled, starch and prepared by mixing an aqueous foam into a gypsum slurry comprising a source of calcined gypsum (commonly known as plaster of Paris), pre-gelled starch and a lignosulfonate dispersant; allowing the so-formed gypsum slurry to set, and then drying the set gypsum core. |