ABSTRACT
The term poloxamer is widely used to describe a series of ABA block coploymers of polyethylene oxide and polypropylene oxide, extensively used in industry as antifoams, emulsifiers, wetting agents , rinse aids, and in numerous other applications [1-5]. Poloxamers are amphiphilic in character, being comprised of a central polypropylene oxide (PO) block, which is hydrophobic, sandwiched between two hydrophilic polyethylene oxide (EO) blocks as shown below:
HO(CHz CHzO)m(tHCHzO)n(CHz CHzO)mH
For the central PO block to serve as an effective hydrophobe, the value of n must be at least 15; the value of m in commercially manufactured poloxamers is such that the EO blocks constitute between 10-80% of the total polymer mass. The absolute and relative masses of the hydrophilic and hydrophobic blocks, on which the physico-chemical properties of the polymers depend, can be controlled during manufacture, enabling the production of poloxamers tailored to specific applications.
