The Effects Of Matrix Mixing On The Properties Of Castor Oil-Based Polyurethane Foams

摘要

Mixing of materials above the required speed in foam production leads to energy loss and affects foam properties such as: foam rise height, density, compressibility, resilience and openness of foam thus; this study was done to analyze the effect of matrix mixing on the properties of castor oil based polyurethane foams. By using the one sheet technique, castor oil based polyurethane foams were prepared from two formulations at different stirrer speed ranging from 120 - 1180 rev/min. The formulation consisted of castor oil as polyol, Toluene diisocyanate, Water, Dimethyl ethanol amine (DMEA), Silicone oil and stannous octoate. Foam properties like Foam height, Density, Tensile strength, Elongation at break and Compression set were tested, it was observed that these properties of the polyurethane foams were very sensitive to mixing; with increase in stirrer speed, strong turbulence at the gas-liquid interface created bubbles which were broken by the stirrer which led to formation of finely dispersed bubbles enhancing the mass transfer rate, a physical examination of the foams revealed that for both foam formulations A and B at low stirrer speeds, big sized cells were formed because the polymerization reaction was not encouraged. But at higher stirrer speeds, smaller cells were formed.