Builder Effects of a Novel Low Molecular Weight Polycarboxylate

A novel sodium polycarboxylate of low molecular weight was obtained from the reaction of cyclohexanone with dimethyl maleate, followed by saponification with sodium hydroxide. The builder effects of the polycarboxylate were studied. The polycarboxylate showed a large buffer index slightly lower than that of sodium tripolyphosphate (STPP). The calcium sequestering capacity of the polycarboxylate was nearly equal to that of STPP, and much larger than that of gluconate, glucoheptonate or saccharate. Plural carboxylate ions without hydroxyl or ether groups at the α position may play an important role in the sequestering of calcium ions. The dispersing ability of manganese dioxide of the polycarboxylate was superior to that of STPP. In the detergency test, the polycarboxylate was found to be excellent, being comparable to zeolite and superior to gluconate, glucoheptonate and saccharate, though somewhat less than STPP.