Modification of Acrylamide Polymers in Aqueous Solution

Poly(acrylamide) and its acrylic acid copolymers were obtained from polymerization of the monomers in aqueous solution using ammonium persulfate/sodium bisulfite initiator following the procedure reported by Fong and Kowalski.5 Depending on the amount of initiator used, the average molecular weights of the polymers were between 6,000 to 50,000 as determined by gel permeation chromatography (GPC). Taurine (2-aminoethanesulfonic acid) and sodium formaldehyde bisulfite were purchased from Aldrich and used without purification. 

The post-modification reactions of acrylamide polymers were run as follows.6 A solution of poly(acrylamide[75mol%]-acrylic acid) (150 g, 27.5% in water) and sodium formaldehyde bisulfite (15.5 g), pH 4.3, was heated to 150° C and maintained at that temperature for four hours in a 300 ml Parr reactor which was equipped with a mechanical stirrer and a thermocouple. The pH of the resulting polymer solution at room temperature was 5.9. 

Transmission IR spectra were obtained on a Beckman 4260 infrared spectrometer. The aqueous samples were cast on silver chloride plates and the solvent was evaporated using a nitrogen stream without heating. 

Carbon-13 NMR spectra were obtained using a JEOL FX90Q operating at 22.5 MHz for carbon. Spectra were obtained using 75° pulses and a 4 sec. delay between pulses with complete proton decoupling. The samples were analyzed in 10 mm tubes. 

---

CHEMICAL MODIFICATION OF ACRYLAMIDE POLYMERS IN AQUEOUS SOLUTION... 

Chemical Modification of Acrylamide Polymers in Aqueous Solution.77... 

---