Author
H.F. Mason
Bio: H.F. Mason is an academic researcher from Rohm and Haas. The author has contributed to research in topics: Methyl methacrylate. The author has an hindex of 2, co-authored 2 publications receiving 246 citations.
Topics: Methyl methacrylate
Papers
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TL;DR: In this paper, the properties of dilute solutions of conventional polymethyl methacrylate designed to characterize the chain length and its distribution, the intramolecular chain interactions and the thermodynamic interactions with solvent and their effects on the chain dimensions, and to establish the accuracy and reproducibility of such data.
155 citations
TL;DR: Light scattering determinations of molecular weight and coil size made at room temperature with three different cells at two wavelengths of incident light and in two solvents (acetone and acetonitrile) on fourteen fractions and six whole polymers of polymethyl methacrylate ranging in molecular weight from 2.7 × 103 to 2.5 × 106 provide a basis for estimation of the validity and reliability of such measurements as mentioned in this paper.
92 citations
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TL;DR: The results of an extensive study of the intrinsic viscosity [η] of a series of linear, homogeneous (anionically prepared) polystyrenes (1.9 ∼ 106.
Abstract: The results of an extensive study of the intrinsic viscosity [η] of a series of linear, homogeneous (anionically prepared) polystyrenes (1.9 ∼106. Above this molecular weight the dependence of [η]/[η]0 on z is satisfactorily predicted by recent calculations of Fixman; [η]/[η]0 is not linear in z contrary to other recent suggestions. The failure of the data on lower molecular weight polymers to be a single‐valued function of z is discussed in terms of partial draining effects.
184 citations
22 Feb 1999
137 citations
TL;DR: In this paper, a range of water-soluble hydrophilic−hydrophobic diblock copolymers of 2-(dimethylamino)ethyl methacrylate and methyl methacelate were shown to form micelles if first dissolved in a nonselective solvent (THF or methanol) and subsequently diluted with water.
Abstract: A range of water-soluble hydrophilic−hydrophobic diblock copolymers of 2-(dimethylamino)ethyl methacrylate and methyl methacrylate were shown to form micelles if first dissolved in a nonselective solvent (THF or methanol) and subsequently diluted with water. Critical micelle concentrations were found to increase with the length of the hydrophobic block if the the hydrophilic block length is fixed. Increasing the overall molar mass of the copolymer also increased the cmc for a given composition. The hydrodynamic diameters and approximate association numbers of these micelles were obtained by dynamic light scattering and analytical ultracentrifugation. Micellar diameters and association numbers were in the range 10−18 nm and 10−33 chains per micelle, respectively, depending on copolymer composition. Increasing the overall molar mass of the copolymer for a given composition produces larger micelles with lower association number. Both micelle size and association number decrease with the length of the hydroph...
124 citations
TL;DR: In this article, some characteristics of photoiniferters of living radical polymerizations with tetraethylthiuram disulphide, benzyl N, N-diethyldithiocarbamate, p -xylylene bis(N, N -diethynectric acid) and tetrakis(N, N -decaramyl) benzene as photoinifiers are described and discussed.
124 citations
TL;DR: The chain length dependence of mean-square radius of gyration ‹S2› for several polymers, stiff or flexible, in dilute solution is compared with that for the Kratky–Porod (KP) wormlike chain, using representative literature data.
Abstract: The chain length dependence of mean-square radius of gyration ‹S2› for several polymers, stiff or flexible, in dilute solution is compared with that for the Kratky–Porod (KP) wormlike chain, using representative literature data. In the region of nK, the number of Kuhn’s statistical segments, below about 50, ‹S2› for all polymers examined is accurately described by Benoit–Doty’s expression for the KP chain. Upward deviations from this expression occur at nK of about 50, regardless of the chain stiffness. Thus, the critical chain length Lc for the onset of excluded-volume effect on the average dimensions of a polymer is approximately proportional to q, the persistence length of the polymer, with a proportionality factor of about 100. The value of Lc estimated from this relation is at least one order of magnitude larger than that predicted theoretically by Yamakawa and Stockmayer.
114 citations