Uses
Castor oil has found numerous applications, many of them due to the presence of the hydroxyl group that allows chemical derivatization of the oil or modifies the properties of castor oil relative to vegetable oils which do not have the hydroxyl group. Castor oil undergoes most of the reactions that alcohols do, but the most industrially important one is reaction with diisocyanates to make polyurethanes.
Castor oil by itself has been used in making a variety of polyurethane products, ranging from coatings to foams, and the use of castor oil derivatives continues to be an area of active development. Castor oil derivatized with propylene oxide makes polyurethane foam for mattresses and yet another new derivative is used in coatings
Apart from castor oil, which is a relatively expensive vegetable oil and is not produced domestically in many industrialized countries, the use of polyols derived from vegetable oils to make polyurethane products began attracting attention beginning around 2004. The rising costs of petrochemical feedstocks and an enhanced public desire for environmentally friendly green products have created a demand for these materials. One of the most vocal supporters of these polyurethanes made using natural oil polyols is the Ford Motor Company, which first debuted polyurethane foam made using soy oil in the seats of its 2008 Ford Mustang. Ford has since placed soy foam seating in all its North American vehicle platforms. The interest of automakers is responsible for much of the work being done on the use of NOPs in polyurethane products for use in cars, for example is seats, and headrests, armrests, soundproofing, and even body panels.
One of the first uses for NOPs (other than castor oil) was to make spray-on polyurethane foam insulation for buildings.
NOPs are also finding use in polyurethane slab foam used to make conventional mattresses as well as memory foam mattresses.
The characteristics of NOPs can be varied over a very wide range. This can be done by selection of the base Natural Oil (or oils) used to make up the NOP. Also, using known and increasingly novel (Garrett & Du) chemical techniques, it is possible to graft additional groups onto the triglyceride chains of the NOP and change its processing characteristics and this in turn will change and modify in a controlled manner, the physical properties of the final article which the NOP is being used to produce. Differences and modifications in the process regime and reaction conditions used to make a given NOP also generally lead to different chemical architectures and therefore different end use performance of that NOP; so that even though two NOPs may have been made from the same Natural Oil root, they may be surprisingly different when used and, will produce a detectably different end product too. Commercially, (AD 2012) NOPs are available and made from; sawgrass oil, soybean oil, castor oil (as an grafted NOP), rapeseed oil, palm oil (kernel and mesocarp), and coconut oil. There is also some work being done on NOPs made from Natural Animal oils.
Initially in the USA, and since early 2010, it has been routinely possible to replace over 50% of petrochemical based polyols with NOPs for use in slab foams sold into the mass market, furniture and bedding industries. The commercialised technology . also eliminates or greatly reduces the odour problem, mentioned above, normally associated with the use of NOPs. This is particularly important when the NOP is to be used at ever higher percentage levels, to try to reduce dependency on petrochemical materials, and to produce materials for use in the domestic and contract furniture segments which are historically very sensitive to "chemical" odours in the final foam product in people's homes and places of work.
Read more about this topic: Natural Oil Polyols