title: Polymer composition and acidification effects on the swelling and mechanical properties of poly(acrylamide-co-acrylic acid) superporous hydrogels.
abstract: Poly(acrylamide-co-acrylic acid) (poly(AM-co-AA)) superporous hydrogels (SPHs) were synthesized and the acidification effects on the swelling and mechanical properties were studied. Gelation exotherms were measured to determine the optimum introduction time for adding a blowing agent. The gelation kinetics decreased with increasing the AA concentration. The maximum equilibrium swelling was observed around an AA weight fraction of 0.4, but the compressive strength decreased monotonically with increasing the AA concentration. Poly(AM-co-AA) SPHs were much less swollen in acidic solution than in distilled water of pH 6.7. The swelling ratio decreased with increasing acidity (decreasing pH). Reduction of water absorption content by acidification led to considerable increase in the mechanical strength.
authors.affiliation: Department of Chemical Engineering, Sungkyunkwan University, 300 Chunchun-dong, Jangan-gu, Suwon, Kyungki 440-746, South Korea. djkim@skku.edu
authors.forename: Dukjoon
authors.initials: D
authors.lastname: Kim
authors.forename: Kwangwon
authors.initials: K
authors.lastname: Seo
authors.forename: Kinam
authors.initials: K
authors.lastname: Park
mesh_terms: D020106:Acrylamide / Q000737:chemistry*; D000179:Acrylates / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D011108:Polymers / Q000737:chemistry*; D016062:Porosity; D013314:Stress, Mechanical
chemical_list: D000179:Acrylates; D020100:Hydrogels; D011108:Polymers; D020106:Acrylamide; C036658:acrylic acid