Solid Polyurethanes Based on Castor Oil using Glycerol and Trimethylolpropane as Crosslinker Agents: Synthesis and Characterization

C. MEIORIN; T. CALVO CORREAS; M. A. MOSIEWICKI; M.I. ARANGUREN; M. A. CORCUERA; A. ECEIZA

Santa Fe

Congreso; Congreso Internacional de Metalurgia y Materiales SAM-CONAMET / IBEROMAT 2014; 2014

In recent years, polyurethanes (PU) have become attractive materials due to their structural versatility. They have numerous applications in various fields like elastomers, thermoplastic, thermosetting, rigid and flexible foams, etc. Nowadays, most polyols used for polyurethanes production are derived from the petroleum industry, but the use of vegetable oils as an alternative for synthetic raw materials has become more important in recent times because of environmental and economic advantages. Vegetable oils are triglycerides consisting of three fatty acids attached to a glycerol structure, offering a large variety and number of reactive sites. In particular, castor oil (CO) is a triglyceride of fatty acids, in which ricinoleic acid is the major constituent (about 90% of CO). It has numerous advantages as low-cost and large availability, and it has been used in the manufacture of very different products, such as lubricants, paints, pharmaceuticals, etc. The natural hydroxyl groups in CO can be chemically reacted to generate bio-based polyols of higher molecular weight. In particular, Lupranol BALANCE 50 (BASF) is a commercial trifunctional polyether polyol based on castor oil (31% CO). The goal of this work is to synthesize polyurethanes from a commercial castor oil based polyol (Lupranol Balance 50, BASF) and methylene diphenyl diisocyanate (MDI). The structure of the polyurethanes were varied by means of two different crosslinking agents, glycerol (Gly) and trimethylolpropane (TMP). The synthesis was carried out in bulk and without catalyst via a one-step polymerization varying the Polyol/MDI/Gly or TMP ratio.