Water soluble polymers from Diels-Alder adducts of abietic acid as paper additives

The diacids resulting from Diels-Alder reaction between abietic acid and ac rylic acid or maleic anhydride were used together with adipic acid to prepa re water soluble poly(amide)s or poly(amide-imide)s. An experimental progra m was worked out with the aim to find the weight ratios between the acid re actants that ensure water solubility of the resulting polymers. The obtaine d soluble polymers were reacted with epichlorohydrin to acquire substituted polymers, also water soluble, but which will crosslink by heating in the s olid state (thermosetting polymers). They can be used as wet strength and s izing agents in the papermaking. Water solubility is required for these uti lizations in paper chemistry.