Showing papers by "Guy C. Berry published in 1979"
TL;DR: In this paper, the viscosity of polyvinyl acetate and its concentrated solutions in diethyl phthalate (DEP) and cetyl alcohol (CeOH) were examined over the molecular weight range 8 × 103 ca. 0.25, increasing with decreasing φ for smaller φ.
Abstract: Data on the viscosity of poly(vinyl acetate) (PVOAc) and its concentrated solutions in diethyl phthalate (DEP) and cetyl alcohol (CeOH) are examined over the molecular weight range 8 × 103 ca. 0.25, increasing with decreasing φ for smaller φ. Both β and T0 depend on φ, and T0 also depends on M at low M.
18 citations
TL;DR: In this article, the rheological properties of two related heterocyclic polymers are studied in concentrated solutions, and the effects of reversible intermolecular association are analyzed and compared for BBB and BBL.
12 citations
01 Jan 1979
TL;DR: The use of a sequential polymerization method for preparing interpenetrating polymer networks with biocomatible surfaces has been studied and an inter penetrating network of the hydrogel and the thermoplastic elastomer was obtained, which absorbed water in the manner of a Hydrogel, but had mechanical properties superior to hydrogels.
Abstract: The use of a sequential polymerization method for preparing interpenetrating polymer networks with biocompatible surfaces has been studied. A hydrogel monomer was made to undergo polymerization with simultaneous cross-link formation, in the presence of a swollen thermoplastic elastomer heterophase block copolymer. On removal of the swelling solvent, an interpenetrating network of the hydrogel and the thermoplastic elastomer was obtained, which absorbed water in the manner of a hydrogel, but had mechanical properties superior to hydrogels. The studies employed a poly(ether-urethane) block copolymer as the thermoplastic elastomer. The materials fabricated included samples in which the interpenetrating polymerization extended throughout the thermoplastic elastomer as well as samples in which the interpenetrating polymerization was confined to a region near the surface of the latter.
12 citations
TL;DR: In this paper, light scattering from concentrated solutions of cellulose acetate in acetone is discussed in terms of exponential correlation functions for refractive index fluctuations related to intermolecular aggregation.
Abstract: Light scattering from concentrated solutions of cellulose acetate in acetone is discussed in terms of exponential correlation functions for refractive-index fluctuations. These are related to intermolecular aggregation. Light scattering, tensile creep and recovery, and hyperfiltration studies with films of cellulose acetate cast from acetone are discussed in terms of the state of aggregation in the films. It is concluded that intermolecular aggregates are probably small and imperfectly formed regions of microcrystallinity stable up to about 210°C, with the overall state one of near amorphous disorder.
10 citations