Abstract
In this experiment, polyurethane was liquefied by high-pressure steam treatment without using acidic or alkaline catalysts and solvent. The results of the viscosity and GPC (Gel Permeation Chromatography) showed that part of the molecular weight of the liquefied urethane attained either diamine level or prepolymer level. Furthermore, variation in the hydroxyl number, the amine value and FT-IR spectroscopy with high-pressure steam treatment time showed that urea and urethane bonds in the polyurethane were specifically broken. In addition, the decomposed liquid could readily react with cross-linking agents, and mechanical properties of recycled polyurethane such as shore hardness, tensile strength, 300% modulus, tearing strength and compression set were almost equal to the original polyurethane. This investigation therefore shows that urethane recycling method we can be established easily. More importantly this recycling method does not adversely affect the environment.
