Combination of zwitterions

In the case of polyampholytes with a betaine structure (6), the acidic and basic groups are situated along the chain backbone. Dependent on the solubility of polyampholytes near the isoelectric point (lEP), they can be water soluble and water insoluble. For instance, the equimolar copolymers of aminoalkyl(meth) acrylates and unsaturated carboxylic acids are water soluble over the complete range of pH-values. On the contrary, copolymers based on vinylpyridines and acrylic (methacrylic, vinyl- or styrenesulfonic) acid are insoluble at the lEP. As a rule most blockpolyampholytes have a wide region of insolubility. Hydrophobic polyampholytes, the behaviour of which is close to polysoaps , represent the combination of zwitterionic and hydrophobic structures. 

EtO CN P p CN H COOMe COOMe Spontaneous copolymerization with 2-oxazolines, CH3NO2, RT Alternating copolymerization by a step-growth mechanism (combination of zwitterions) [69]... 

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