Utilization of sludge produced by freon decomposition for constructive materials has been studied and the following results were obtained. Mixing of mortars became difficult with increase in the sludge content due to the increase in viscosity, but it was certainly possible to operate using ca. 10% sludge in aggregates. Both bending and compressive strengths of the concrete products obviously increased during curing. Bending strength of the products replaced with 10% sludge was almost equal to that of control prepared without sludge, but more than 20% it decreased remarkably. Relatively small decrease in compression strength was observed. Both bending and compressive strengths in wash-dry sludge series were superior to that of wet-raw sludge or dry sludge series. Stabilities to sulfuric acid and shrinkage increased with the use of the sludge. The results apparently indicate that the sludge can be used as a part of constructive materials such as interlocking block. The fact proved that a freon decomposition system has been completed without formation of waste products.

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In this paper, a novel titration method using potentiometry was proposed. The titration of hydroperoxide content in thermal-degraded PP-impact copolymers was performed by this novel potentiometry method. In the initial degradation step of the copolymer containing antioxidant, the production of hydroperoxide was not observed because of existence of antioxidant. After the antioxidant was completely consumed, the production of hydroperoxide began to be observed. This behavior completely consisted with that of the decrease in the molecular weight measured by GPC. This result implied that the beginning of degradation was accurately caught by this titration of hydroperoxide. Moreover, this titration method was more sensitive to the hydroperoxide content as compared with the conventional titration such as UV and manual titration by iodimetry, and its limit of hydroperoxide detection was found to be 2meq.kg^-1 (mmol·kg^-1). It was concluded that this novel titration method was a very powerful tool for the estimation of PP degradation.

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