Hydrophilic/hydrophobic copolymers improvement

One way of improving the physical and mechanical properties of the polymeric materials produced was to copolymerize the original monomers with stiffer comonomers, whose corresponding homopolymers are endowed with high thermal and mechanical properties. Therefore, 1,4-cyclohexanedimetha-nol was copolymerized with 1,3-propanediol and succinic acid. Segmented copolymers between oligofpropylene succinate)s and PEG were also produced in order to modify their hydrophilic/hydrophobic properties. 

In RPC systems, the retention is weaker on weakly or moderately polar stationary phases such as on phenyl- or cyanopropyl-bonded phases than on an alkylsilica phase. RPC separations on phenyl or cyanopropyl columns may show selectivities differing from those observed on Cix or Cs phases, but their main advantage is lower concentration of organic solvent required to elute weakly polar samples, which may potentially reduce the separation time. For the great majority of samples, however, the selectivity of separation is generally better on alkylsilica-bonded phases. On the other hand, retention of hydrophilic samples can be increased and their separation improved on columns with a high amount of bonded carbon (polymeric bonded phases) or on hydrophobic organic polymeric materials such as styrene-divinylbenzene copolymers. 

The proton conductivity of sulfonated poly(ether ether ketone) can be improved by using special types of PEEK, namely, block copolymers consisting of a hydrophobic and a hydrophilic block. 

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