Inter-and intra-molecular association in alcohol solutions of poly(n-vinyl-2-pyrrolidone) with molecular weight of 670,000 is investigated by viscometric techniques. While the limiting viscosity number, [r/], of the polymer was observed to remain almost constant in methanol, ethanol and n-propanol solutions, the Huggins constant, ku showed an increase with increasing carbon content of the alcohols studied. Addition of denaturing agents, such as urea and guanidine hydrochloride, (GC) caused a decrease in both of the above values. The changes brought about in these parameters by the denaturing agents were found to be a result of the changes taking place in the hydrophilic and hydrophobic interactions among polymer, solvent and additive molecules.

Poly(N‐vinyl 2‐pyrrolidone‐g‐citric acid) (PVP‐g‐CA) hydrogels with varying compositions were prepared from ternary mixtures of N‐vinyl 2‐pyrrolidone–citric acid–water by using 60Co γ‐rays. The effect of gel composition on the uranyl ions adsorption capacity of PVP‐g‐CA hydrogels was investigated. Uranyl adsorption capacity of these hydrogels were found to be in the range of 18–144 mg [UO 2+2]/g dry gel from the aqueous solution of uranyl nitrate and 22–156 mg [UO 2+2]/g dry gel from the aqueous solution of uranyl acetate, depending on the content of citric acid in the hydrogel, while poly(N‐vinyl 2‐pyrrolidone) hydrogel did not sorb any uranyl ion. The swelling of PVP‐g‐CA hydrogel containing 2.7 mol % CA was observed in water (1620%), in uranyl acetate solution (1450%) and in uranyl nitrate solution (1360%), as compared to 700% swelling of pure PVP hydrogels. The diffusion coefficients were varied from 12.57 up to 4.04 • 10−8 m2 s−1. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1037–1043, 2000

ABSTRACT:The ␥-ray-induced copolymerization of vinyl triethoxy silane (VTES) with methyl methacrylate (MMA) was developed to be used in the simultaneous preservation and consolidation of archeological artifacts. A detailed analysis was performed to characterize the copolymerization reaction and conversion. The copolymers were characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), gel permeation chromatography (GPC), and elemental analysis techniques. The mol fraction of VTES units in the synthesized copolymers were determined by elemental analysis of silicone pertaining to VTES segments using inductive coupling plasma spectroscopy (ICP). The effect of VTES mol fraction in the initial feed and the irradiation dose (6.5, 8.5, 10.0 kGy) on the yield of copolymerization was investigated. The yield of the copolymerization was found to decrease with increasing the VTES mol fraction in the monomer feed, and to increase with increasing the irradiation dose at each monomer composition. However, using the data obtained from the ICP measurements, the mol fraction of the VTES units in synthesized copolymers was determined to increase with increasing the VTES concentration in the initial monomer feed.