Synthesis of palm oil based polyol via glycerolysis and transamidation reactions for polyurethane foam production

Abstract

Renewable sources like vegetable oil have been used to prepare many polymeric resins due to the awareness on environmental issue and depletion on petrochemical sources. In polyurethane (PU) production, petroleum-based polyols such as polypropylene glycol (PPG) have been replaced with plant-based polyols from canola oil, soybean oil and palm oil. However, these vegetable oils need to be chemically or physically modified in order to increase their functionalities especially hydroxyl groups. In this study, palm oil (PO) had been modified via two different reaction routes, namely, glycerolsis and transamidation. FTIR spectra of both routes confirmed that the hydroxyl groups (-OH) had been successfully introduced into the palm oil molecular structure. The modified PO was then be reacted with p-diphenylmethane diisocyanate (p-MDI) at 1:1 NCO:OH ratio in the presence of distilled water as blowing agent and silicone surfactant as foam stabilizer to produce palm oil based PU foam. Hardness test was conducted to study type of PU foam produced. Both foams exhibited nearly similar values at shore D 33.6 and 35.4 respectively, which these values fall within the range of rigid PU foam (shore D 30-59). The foams have potential to be used in many non-load bearing application such as insulator in building and refrigerator.