Gypsum retarders yog cov tshuaj additives siv los tswj kev teeb tsa tus nqi ntawm gypsum-raws li cov ntaub ntawv hauv tsev; Lawv feem ntau yog siv rau hauv daim ntawv thov xws li gypsum plasters thiab ntau yam khoom gypsum.
Feem ntau siv retarders poob rau hauv peb pawg tseem ceeb: cov organic acids thiab lawv cov ntsev soluble, alkaline phosphates, thiab protein-raws li retarders. Cov qeb ntawm cov organic acids thiab lawv cov ntsev soluble muaj xws li citric acid, sodium citrate, tartaric acid, potassium tartrate, acrylic acid, thiab sodium acrylate; ntawm cov no, citric acid thiab nws cov ntsev yog cov ntsiab lus ntawm kev tshawb fawb ntau tshaj plaws. Citric acid thiab nws cov ntsev muaj peev xwm ua kom muaj zog tiv thaiv kab mob txawm tias ntxiv rau qhov me me. Phosphate-raws li retarders feem ntau muaj sodium hexametaphosphate, sodium polyphosphate, thiab sodium tripolyphosphate. Tsis tas li ntawd, muaj cov amino acid-raws li gypsum retarders, xws li hloov cov amino acid derivatives. Feem ntau, gypsum retarders tshwm sim dawb los yog xim av hmoov uas yog yooj yim soluble hauv dej.