| Abstrakt: |
Some water-insoluble polymers, such as polyvinylpyrrolidone-acetate copolymer, polyvinylalcohol-acetate copolymer, and polypropylene glycol dissolved in aqueous solutions of urea, alkylureas, amides, guanidine hydrochloride, and also of tetrabutylammonium bromide (Bu4NBr) have been studied. The intrinsic viscosities and clouding points of the polymer solutions rise with increase of concentration of these substances. Aqueous urea dissolves these hydrophobic polymers by breaking the ordered water structure around the hydrophobic parts. The effects of alkylureas and acetamide are complex because these substances include in the same molecules groups that break, and groups that form water structure. Aqueous Bu4NBr dissolves the polymers by association in a manner similar to that of surfactants but far less efficiently for dissolution. Me4NBr is nearly ineffective for dissolution of these polymers. |
