Biodegradable water-soluble polycarboxylic acid design: Biodegradability and builder performance in detergent formulation of partially dicarboxylated polyuronide containing sugar residues in the backbone

Partially dicarboxylated polyuronide having a variable amount of unreacted sugar blocks as an enzymatically cleavable segment was prepared by the controlled oxidation of pectic acid and alginic acid. It was found that partially dicarboxylated polyuronides containing uronide blocks showed better biodegradability than those having no uronide block in the polycarboxylate chain. The rate of biodegradation varies according to the degree of dicarboxylation. It was confirmed that dicarboxy polyuronides containing more than 70% unreacted uronide residues tended to biodegrade quickly. The biodegradability obtained by the BOD test and the enzymatic degradability are well correlated, suggesting that these polymers are first cleaved at the sugar blocks by carbohydrase with subsequent assimilation of the resultant oligomeric fractions. Detergency was dependent on the content of the carboxylate groups in the polymer. The polymers with high carboxylate contents showed better builder performance. The detergency of dicarboxy pectic acid was better than that of dicarboxy alginic acid when compared on the basis of an equal degree of dicarboxylation.