Degradation Rate Of Poly Research Articles

DEGRADATION RATE OF WATER-SOLUBLE POLYMERS BY OZONE

Water-soluble polymers were degraded by ozone, and the degradation rate defined by the change of weight average polymerization degree per unit time was obtained. The degradation rate of poly(oxyethylene) (PEG) was proportional to the 1.5 to 2.0 power of the polymerization degree, and was 20 to 60 times that of poly(acrylamide) (PAAm). The experimental results of PEG and PAAm were correlated as a function of polymerization degree, temperature, dissolved ozone concentration and OH− ion concentration. The degradation rate of poly(sodium acrylate)(PANa) was proportional to the 2.0 power of the polymerization degree when no other electrolyte was added. However, the degradation rate of PANa decreased with the increase in NaCl concentration, and approached that of PAAm in the range of high NaCl concentrations.

Degradation rate of poly(oxyethylene) in water by ozone.

The degradation rate of water-soluble poly(oxyethylene) (PEG) was studied under the condition of chemical reaction rate controlling, using a bubble column of 0.05 m I.D. and 0.6 m high. The degradation rate of PEG, of which initial viscosity-average molecular weight is 32, 000, is a function of viscosity-average molecular weight, dissolved ozone concentration and OH- concentration. The activation energy of the reaction is found to be 6.2 × 104 J ⋅ mol-1. An empirical equation of the degradation rate of PEG is obtained in the range of pH=5.5-8.1. The mechanism of the ozonation was studied on the basis of IR and NMR spectrochemical analysis, and a degradation scheme of PEG is proposed.