Interaction of diazoresins and sulfonate containing polyelectrolytes

The interaction of the photosensitive strong polycations diphenylamine-4-diazonium-formaldehyde resin (DR) or 2-nitro-N-methyl-4-diazonium-formadehyde resin (NDR) with the sulfonate-containing polyelectrolytes (SPE) poly(sodium vinylsulfonate) (PSV), poly(sodium-p-styrenesulfonate) (PSS), poly(potassium salt, 3-sulfopropyl acrylate) (PPSA) or poly(potassium salt, 3-sulfopropyl methacrylate) (PPSMA) has been studied. It was found that water-insoluble DR-based polyelectrolyte complex (i-DR-PEC) was formed at molar ratios (chain units) of polyanions to diazoresins of less than 1:1, but the added excessive polyanion would dissolve the i-DR-PEC to form water-soluble DR-based polyelectrolyte complex (s-DR-PEC). This dissolution process of PECs is related to the structure of their components: the polyanion with flexible longer side-chain or the DR with stronger hydrophobic group exhibits high ability to dissolve the PEC. It is believed that the hydrophobic interaction between the excessive polyanion molecules and DR-PEC chains plays a key role in the dissolution of i-DR-PEC. The influences of molecular weight of polyanion and concentration of NaCl on the dissolution of i-DR-PEC and the thermal stability of s-DR-PEC in excessive polyanion aqueous solution have also been investigated.