The polymerization of acrylamide initiated by an ascorbic acid–peroxydisulfate redox system was studied in aqueous solution at 35 ± 0.2°C in the presence of air. The concentrations studied were [monomer] = (2.0–15.0) × 10−2 mole/liter; [peroxydisulfate] = (1.5–10.0) × 10−3 mole/liter; and [ascorbic acid] = (2.84–28.4) × 10−4 mole/liter; temperatures were between 25–50°C. Within these ranges the initial rate showed a half‐order dependence on peroxydisulfate, a first‐order dependence on an initial monomer concentration, and a first‐order dependence on a low concentration of ascorbic acid [(2.84–8.54) × 10−4 mole/liter]. At higher concentrations of ascorbic acid the rate remained constant in the concentration range (8.54–22.72) × 10−4 mole/liter, then varied as an inverse halfpower at still higher concentrations of ascorbic acid [(22.72–28.4) × 10−4 mole/liter]. The initial rate increased with an increase in polymerization temperature. The overall energy of activation was 12.203 kcal/mole in a temperature range of 25–50°C. Water‐miscible organic solvents depressed the initial rate and the limiting conversion. The viscometric average molecular weight increased with an increase in temperature and initial monomer concentration but decreased with increasing concentration of peroxydisulfate and an additive, dimethyl formamide (DMF).

INTRODUCTIONAmino polymers have been extensively used in industry. The addition of primary or secondary mines to vinyl double bonds activated by electron attracting groups is well known.' Hulse2 obtained a water-soluble poly(amide-mines) by the reaction of NJV-methylenebisacrylamide with piperazine in water. Later on, Danusso et al.34 synthesized linear poly(amide-amines) by the polyaddition of primary monoamines or bis(secondary) diamines to bisacrylamides. They further confirmed that the polymerization is a nucleophilic polyaddition with an anionic mechanism and is not influenced by the presence of the inhibitors of radical polymerization. The polyaddition reaction of bisacrylamide with bis(secondary) diamine or primary amine that leads to poly(amide-amines) may be accomplished with acrylic diesters or divinyl sulfone instead of bisacrylamide.6 Yoda et al." obtained transparent poly(amide-amines) from acrylates with diamines. Ferruti3s8 prepared linear poly(amide-amines) from hydrazine and bisacrylamides. However, they observed that the linear polymers could be obtained from equimolar amounts of hydrazine and bisacrylamide, whereas crosslinked polymers were obtained with higher amounts of bisacrylamides. Imai et aL9 have studied the polyaddition of aromatic diamines with N,N'-methylenebisacrylamide. They have also studied the effect of solvent and acidic catalyst on the molecular weight of poly(amide-amines).A series of poly(amide-amines) with sulfone and ether linkages was prepared in the present study and their structure property relationship was examined. EXPERIMENTAL MaterialsAcrylamide (Cyanamide, USA) was recrystallized twice from methanol before use. Paraformaldehyde (BDH, England) was used as received. n-Butyraldehyde (BDH, England) and benzaldehyde (local market) were purified by distillation before use. 4,4'-Methylene dianiline (Bayer, A. G., West Germany), and 4,4'-oxydianiline (EGA Chemie, West Germany) were recrystallized from benzene and tetrahydrofuran (THF), respectively before use. m-Cresol, ethylene dichloride, and glacial acetic acid were purified by standard methods. Bisacrylamides were prepared by the method described by Feuer and Lynch.lo Sulfone ether diamines were prepared by the method described by Kawakami and co-workers.ll PolymerizationA typical example of polycondensation in the synthesis of poly(amide-amine) from N,N'-methylenebisacrylamide and 4,4'-bis(4-amino phenoxy) diphenyl sulfone is given below:Into a 50-mL, three-necked, round-bottomed flask equipped with a thermometer, nitrogen gas inlet, reflux condenser, and magnetic stirrer were placed 0.77 g (0.05 mol) of N,N'-methylenebisacrylamide, 2.16 g (0.05 mol) of 4,4'-bis(4-amino phenoxy) diphenyl sulfone, 0.4 cm3 of glacial acetic acid, and 10 cm3 of m-cresol. The reaction mixture was stirred at 100°C for 24 h in a nitrogen at-