Reference

Nature of water in synthetic hydrogels

Nature of water in synthetic hydrogels. III. Dilatometry, specific conductivity, and dielectric relaxation of poly(2,3-dihydroxypropyl methacrylate). Choi, Sunhee; Jhon, Mu Shik; Andrade, Joseph D. (Dep. Chem. Sci., Korea Adv. Inst. Sci., Seoul, Korea). J. Colloid Interface Sci., 61(1), 1-8 (English) 1977. CODEN: JCISA5. DOCUMENT TYPE: Journal CA Section: 35 (Synthetic High Polymers) Poly(2,3-dihydroxypropyl methacrylate) (I) [28474-30-8] hydrogels of varying water concns. contained 3 types of water: bound, bulk, and an intermediate form. I gels of 60% water content had a sharp vol. change at 0.degree. in thermal expansion measurements; those contg. 20% water showed no anomalous change. The dielec. const. of I gels was higher than that of water at low frequency, but decreased with increasing frequency.

Water vapor sorption of stereoregular poly(2-hydroxyethyl methacrylate) and poly(2,3-dihydroxypropyl methacrylate)

Water vapor sorption of stereoregular poly(2-hydroxyethyl methacrylate) and poly(2,3-dihydroxypropyl methacrylate). Sung, Y. K.; Jhon, M. S.; Gregonis, D. E.; Andrade, J. D. (Dep. Chem., Dongguk Univ., Seoul, S. Korea). Pollimo, 8(2), 123-31 (English) 1984. CODEN: POLLDG. ISSN: 0379-153X. DOCUMENT TYPE: Journal CA Section: 36 (Physical Properties of Synthetic High Polymers) Hydrophilic three-dimensional methacrylate polymer networks(hydrogels) were prepd. from 2-hydroxyethyl methacrylate and 2,3-dihydroxypropyl methacrylate. Highly isotactic poly(2-hydroxyethyl methacrylate) (I) [70614-47-0] and highly syndiotactic poly(2-hydroxylethyl methacrylate) (II) [70559-14-7] were also studied. The sorption of water vapor in the different tactic polymers was measured as a function of water activity. The results were interpreted in terms of Anderson's modified Brunaeur-Emmett-Teller theory and Hailwood-Horrobin theory of sorption. The former fitting to the exptl. isotherms is up to 0.7 equil. relative humidity, while the soln. theory of Hailwood-Horrobin gives a somewhat better fit to most of the exptl. isotherms over the entire range of equil. relative humidity. Water vapor sorption by the methacrylate polymers is affected by tacticity and the no. of hydrophilic sites in mols. The amt. of water vapor sorbed by I was greater than that by II. Theor. water sorption models and anal. of the data suggest that I exists in a surface configuration and structure which provides a larger no. of water binding sites than the syndio- or hetero-tactic polymers. Poly(dihydroxypropyl methacrylate) [28474-30-8] water sorption data and anal. is consistent with its higher hydrophilicity due to the presence of 2-hydroxyl group per repeat unit. These data are also consistent with thermal anal. studies of bound water in fully hydrated systems.