PENGARUH PEG, KATALIS, & MINYAK JARAK TERHADAP SIFAT MEKANIK POLIURETAN

Synthesis of polyurethane prepared by mixing of alcoholysis castor oli and polyethylene glycol (PEG) with diisocyanate (4,4-diphenylmethane diisocyanate/ MDI) has been carried out. The castor oil in this research had been alcoholysis by methanol and Acid as a catalyst. The catalyst used between 1% – 5%. The composition of castor oil and methanol were varied. The analysis indicated that the alcoholyzed castor oil has a highest hydroxyl number, i.e 436,64 mg/g, at processing alcoholysis with the composition 1:15 and 5% catalyst. The proses of polimerization had been investigated at room temperature and 60 minutes. The characterization of polyurethane has been done by measurements of mechanical properties involved are tensile strength, and elongation at break. The result showed that increasing of the acid catalyst concentration with the same of composition castor oil and methanol resulting in the increase tensile strength. On the other hand, increasing of the acid catalyst concentration resulting of the decrease elongation at break. Beside that, the result showed increasing the methanol in alcoholysis and the equivalent catalyst concentration resulting in increase tensile strength and decrease elongation at break. This means that the optimal condition of synthesis was at the composition castor oli and methanol 1 : 15 and 5 % of an acid catalyst, where on these condition was produced the polyurethane with 7,9167 kgf/cm2, and 73% of the tensile strength and percentage of elongation at breaks, respectively.