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Water hardness control by detergent builders
Author(s) -
Nagarajan M. K.,
Paine H. L.
Publication year - 1984
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02636370
Subject(s) - hard water , sodium , chemistry , ion exchange , ion , materials science , chemical engineering , metallurgy , engineering , organic chemistry
Commercial detergent additives to control water hardness are of three main types, sequestrant, precipitant or ion‐exchange builders. These builders lower the free hardness ion (Ca +2 , Mg +2 ) concentration in a wash system by different mechanisms. An electrometric experimental method was used to evaluate the relative water hardness control performances of different builder‐types under conditions closely simulating those of detergent's end‐use. Experimental data for the following builders are presented: EDTA, NTA, STPP, PAA, CMOS, Na‐Citrate, Na 2 CO 3 and type A zeolite. It is shown that the relative rankings of the various builders in water hardness control differ significantly with differences in use level concentration of the builder (0.005–0.100 gm per 100 ml). The application of the method to the selection of optimum molecular weight range of the newly emerging class of organic polymeric detergent builders like sodium polyacrylates (Na‐PAA) (M w =2000−220,000) also is discussed.