Castor oil is increasingly finding application in the manufacture of polyurethane foams. The polyurethane is produced from polyols based on castor oil. Polyols can be reacted with diisocyanates to make polyurethanes.
There are a limited number of naturally occurring vegetable oils (triglycerides) which contain the unreacted hydroxyl groups that account for both the name and important reactivity of these polyols. Castor oil is the only commercially-available natural oil polyol that is produced directly from a plant source: all other natural oil polyols require chemical modification of the oils directly available from plants.
Features of Castor Oil Based Polyurethane
- Superior to PPG (Polypropylene Glycol) or polyester in water and hydrolysis resistance
- Superior to PPG or polyester in insulation
- Lower viscosity than Polybutadiene or Polyester
- One of the most challenging issues of polyurethane flooring is heat and humidity. The urethane produced from castor oil is stable under high heat and humidity.
Prominent Companies and Efforts
- In September 2013, Jayant Agro Organics Ltd, an Indian oleochemical company, have entered into a joint venture agreement with two Japanese firms – Mitsui Chemicals Inc and Itoh Oil Chemicals Co Ltd – for manufacturing castor oil based polyols.
- In September 2011, Ford and BASF have teamed up to develop a sustainable, plant-sourced castor oil-based polyurethane foam product for the 2012 Ford Focus instrument panel.
- ACTEGA Rhenania (www.actega.com) has developed a novel series of solvent-free polyurethane adhesives for laminates to be used in packaging. Raw material involved in polyurethane is castor oil derivative.
- In Feb 2009, Keetsa, a San Francisco retailer, manufactured mattresses using polyurethane foam made from castor oil. The product called as Biofoam, partially utilized castor oil (The other 88 percent, though, is still petroleum-based)
- BASF produces Lupranol Balance, a polyol made up of 31% castor oil by weight. BASF’s European polyurethane (PU or PUR) subsidiary, Elastogran, produces it for the synthesis of soft PU foams used in mattresses.
- Alberdingk Boley, a German based company, produces castor oil based aliphatic polyurethane dispersions.