Through the introduction of phosphonic group into carboxylic group, Phosphino-Carboxylic Acid(PCA) has good dispersion property for scale of calcium carbonate and calcium phosphate in circulating cool water system. Phosphino-Carboxylic Acid(PCA) has good scale inhibition for barium sulfate, strontium sulfate and silica scale.

Phosphino-Carboxylic Acid(PCA) has below properties as well. 

Cost effective
Thermally and hydrolytically stable
Excellent performance under pulp/paper conditions
Effective against barium sulphate and calcium oxalate
Can be used in applications where steam may contact food
Cost savings by removing need for more expensive speciality copolymers
Provides extended performance under boiler conditions at pressures up to 1000 psig
Outperforms polyacrylates in pulp/paper applications
Multifunctional scale control and dispersancy in paper machines