Resource recovery and recycling of materials and products, including polyurethanes is viewed as a necessity in today's society. Most urethane polymers are made from a polyol and a diisocyanate. these and be chemicals such as water, diamines or diols that react with isocyanate groups and add to the polymer backbone. The problems of recycling polyurethane wastes has major technological, economic and ecological significance because polyurethane itself is relatively expensive and its disposal whether by burning is also costly. In general, the recycling methods for polyurethane could be classified as mechanical, chemical and feedstock. In the chemical recycling method, there are hydrolysis, glycolysis, pyrolysis and aminolysis. This study, the work was carried out glycolysis using sonication ant catalyzed reaction. Different kinds of recycled polyols were produced by current method(glycolysis), catalyzed reaction and sonication as decomposers and the chemical properties were analyzed. The reaction results in the formation of polyester urethane diols, the OH value which is determined by the quantity of diol used for the glycolysis conditions. The glycolysis rates by sonication for the various glycols, increased as fallows: PPG <PEG < DEG < EG. The recycled polyol of sonication reaction had much higher OH value, much lower decomposition temperature and time than the recycled polyol of current method in which same glycols and catalyst were used.

Waste electrical and electronic equipment (WEEE) has been received much attention recently due to rapid changes in materials and shorter replacement of consumer products. Most of WEEEs are collected and recycled at the designated recycling centers in Korea, and final residues after recycling, sorting and shredding them to separate valuable and recyclable parts in series are left as forms of shredded plastic mixtures, which would be a problem to be resolved. By further plastics separation the polyurethane foams are mostly remained and becomes waste to be treated by appropriate methods. Gasification to produce syngas and incineration to recover energy for such polyurethane foam waste could be utilized instead landfill presently treated. In this study the experiment was conducted to evaluate such performance characteristics of thermal processes. Pelletized solid refuse fuel (SRF) was fabricated to feed into the test furnace even though it was light with low density. Thermogravimetric analysis, proximate analysis and higher heating value were made. During gasification and incineration, gas composition with gaseous pollutants were measured. Due to nitrogen content in polyurethane, nitrogen containing gaseous substances such as NH3 and HCN were observed with varying equivalent air ratios (ERs). The assessment of polyurethane waste foam to energy using incineration and gasification was made with finding out the optimal condition of air injection to emit less pollutants in both operations. Produced syngas could be utilized as energy fuels by lowering pollutants emission.

In order to utilize waste wood chip for pavement, a polyurethane resin that is both eco-friendly and suitable for bindingwood chip was developed as the binder, and workability was examined through laboratory experiment for characteristicsof waste wood chip mixture using the polyurethane resin and through test pavement on the field. The new resin was aVOC reduction type free from plasticizer and solvent classified as endocrine-disrupting chemicals and environmentalhazardous substances, and NCO equivalents were set at 8, 9, 10 and 11% by modifying the polyisocyanate-polyol ratio.Laboratory experiment showed that polyurethane resin with NCO equivalent of 9% and 10% had excellent characteristicsas binder for waste wood chip. In the field experiment applying waste wood chip and polyurethane resin in the massratio of 1:0.8, tensile strength of the pavement system was about 30% higher than that using polyurethane resin currentlybeing sold, and permeability coefficient and elasticity thereof were the same as that using the resin currently being sold.Also, examination of compaction methods for waste wood chip pavement system showed that non-heating hand rollerand compactor had the problem of the “waste wood chip - resin mixture” sticking to the roller during the compaction but that heating hand roller had excellent workability and could achieve good planation surface relatively easily.