Properties of block copolymers phase separation in solution and at solid state

1 Properties of block copolymers phase separation in solution and at solid state 

Block copolymers composed of two or three hydrophilic and hydrophobic blocks possess amphiphilic properties and are used widely as nonionic surfactants. Poloxamers are triblock copolymers polyoxyethylene-polyoxypropylene-polyoxyethylene (PEO-PPO-PEO), commercially known 

Synthesis of poloxamers begins with creation of the hydrophobic block by addition of propylene oxide to propylene glycol. Then the hydrophilic blocks are added by polymerisation of ethylene oxide, as shown in Equation 4.1. 

The total molecular weight of poloxamers can vary from 1000 g/mol to 16 000 g/mol, and the hydrophilic segment can comprise between 15% and 90% of the molecule. Box 4.1 describes the code names of poloxamers. 

CMC depends on the copolymer, the solvent and the temperature. Unexpectedly, solubility is greater in cold than in warm water. Hydrogen bonds are formed between the oxygen atoms of the macromolecule and 

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