SYNTHESIS AND CHARACTERIZATION OF ANTI FLAMMABLE CASTOR OIL BASED RIGID POLYURETHANE FOAM

Abstract

The versatility of rigid polyurethane foam (RPUF) has made it an indispensable material in construction, insulation and automobile industry. The global growing interest in RPUFs is towards the exploring of novel renewable sources. Being relatively inexpensive and a renewable, vegetable oils are located as the potential candidates for RPUFs production. In the present research work an attempt has been made to develop rigid polyurethane foam from castor oil. The effect of different process parameters on the properties of the RPUFs have been are extensively studied. To study the effect of the MDI/Polyol ratio, different formulations of the foams with varying amount of MDI were tested. Mechanical strength of the resulted polyurethane foams was found to be increased with increase in the MDI content. SEM studies had also shown evidence for improved morphology and closed packing with increase in MDI content. Further the RPUF was examined for the different surfactant concentrations to establish its function. Silicon oil was found to have significant effect on the mechanical properties of the foam. It emulsify the incompatible foam ingredients and promote bubble generation during mixing which in turn regulates the foam structure and cell size, thus influence the foam properties. As RPUFs suffer from drawbacks such as lack of mechanical strength and thermal stability, it had been loaded with the different amounts of glass fiber. The higher values of hardness, tensile and compressive strength, with a relatively linearly increasing trend were observed. SEM studies had also revealed improved cell morphology with dense packing in RPUGFs. The mechanical properties and process parameters of these RPUFs are needed to be optimized to control the reliability of the iv products and to make the resulted product more economic. For this, the most common statistical approach i.e. Taguchi DOE was studied because of its easiness and reliability. As RPUFs suffers from the problem of being highly combustible, so different anti-flamming agents were incorporated in the foam. It was observed that thermal and anti-flamming properties of RPUFs were found to be significantly increased by incorporating TDCPP due to well homogenization of the flame retardant materials and polyols. The resulted castor oil based RPUFs due to their high strength, anti flammable nature and load bearing capacity are suitable to be used as light weight moldable engineering material for various applications.