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  • 11
    Electronic Resource
    Electronic Resource
    Core-shell emulsion copolymerization of styrene and acrylonitrile on polystyrene seed particles (1984)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 22 (1984), S. 2197-2215 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Seeded emulsion copolymerization of an azeotropic composition of styrene (St) and an acrylinitrile (AN) comonomer mixture in polystyrene (PS) seed at different polymerization temperature of 55-75°C were investigated. The kinetic data showed a transition temperature at 65°C, above which the activation energy of polymerization is low, 6.1 Kcal/mol, compared with 9.8 Kcal/mol below it. The particle-size results and thin layer chromatographic (TLC) data showed two types of particle of different composition and morphology in the final latex system: a smaller size of (St-AN) copolymer and a larger size of core-PS and (St-AN) copolymer shell, with a zone of PS grafted (St-AN) copolymer in between. Various polymerization parameters, that is emulsifier concentration, type of seed particle and its size, and monomer/polymer ratio, were studied and their effects on particle size and particle morphology were examined. The percent of grafted core-PS was 10% below a polymerization temperature of 65°C and 40% above that temperature. By adjusting the size and number of the seed particles, monomer-polymer ratio, and emulsifier concentration conditions were established in which a final copolymer latex with “perfect” core-shell morphology was achieved.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1984.170220921
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  • 12
    Electronic Resource
    Electronic Resource
    Synthesis and properties of poly(2,5-thienylene) (1980)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2869-2873 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1980.170180910
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  • 13
    Electronic Resource
    Electronic Resource
    Batch and semicontinuous emulsion copolymerization of vinyl acetat-butyl acrylate. I. Bulk, surface, and colloidal properties of copolymer latexes (1983)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 21 (1983), S. 2363-2382 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Vinyl acetate (VAc)-butyl acrylate (BuA) comonomer mixtures with various composition were polymerized by batch and semicontinuous emulsion polymerization processes. PVAc and PBuA homopolymer latexes as well as the (VAc-BuA) copolymer latexes were characterized with respect to particle size, molecular weight, acid end groups on particle surfaces, and colloidal stability against electrolytes. The surface and colloidal properties of these latexes were also compared before and after aging and acid hydrolysis. The average particle size of batch latexes was independent of copolymer composition, whereas for semicontinuous latexes it decreased with increasing BuA content and was always lower than that of the corresponding batch latex. The molecular weight distribution (MWD) for batch latexes was narrower and much less dependent on composition than that of the semicontinuous latexes; bimodal MWD was found in most semicontinuous latexes with a substantial amount of low MW fraction. The total weak and strong acid end groups on particle surfaces for semicontinuous latexes is higher, and more dependent on composition, than the batch latexes. Acid-induced hydrolysis results in a drastic change in the type and concentration of the surface groups of the semicontinuous latex particles. Colloidal stability against electrolytes showed that both electrostatic (due to surface acid groups) and steric [due to surface poly(vinyl alcohol)] mechanisms are contributing. However, for semicontinuous latexes, increasing PVAc content above 50 mol % resulted in a proportional increase and ultimately dominant role of steric stabilization. The results were interpreted in terms of differences in reactivity ratios and water solubilities of the two monomers and their effects on the locus of initiation and growth in the two polymerization processes, as well as the monomer sequence within the polymer chain and degree of homogeniety of the copolymer composition within the particle.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1983.170210821
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  • 14
    Electronic Resource
    Electronic Resource
    Preparation and characterization of poly(copper 2,3,9,10,16,17,23,24-octacyanophthalocyanine) (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 23 (1985), S. 1579-1587 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dark blue poly(copper 2,3,9,10,16,17,23,24-octacyanophthalocyanine) has been prepared by reacting 1,2,4,5-tetracyanobenzene with cuprous chloride in 1-methyl-2-pyrrolidone at ca. 150°C. The product has been characterized by elemental analysis, thermal analysis, infrared and UV-VIS spectroscopies. The polymer has high purity and exhibits good thermal stability in an inert atmosphere.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.170230528
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  • 15
    Electronic Resource
    Electronic Resource
    Competitive growth of polystyrene latex particles: Theory and experiment (1973)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 11 (1973), S. 447-452 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The results of the competitive growth of monodisperse polystyrene latex particles reported earlier by Vanderhoff et al. are reconciled with the predictions of more recent particle-growth theories. In these experiments, monomer was polymerized in a seed latex comprised of a mixture of two monodisperse latexes so that the particles of different size competed with one another for the available monomer and free radicals. The results were expressed in terms of the equation dV/dt = kDc, where V is the particle volume, D the diameter, and k and c constants. The value of c is zero for emulsion polymerizations obeying Smith-Ewart Case II kinetics and 3 for polymerizations in homogeneous phase. Experimentally, for water-soluble persulfate initiator, the value of c was 2.5 for particle sizes larger than about 1500 Å and decreased toward zero as the particle size was decreased below 1500 Å; for oil-soluble benzoyl peroxide initiator, it was 2.5 until the larger particles reached the critical size needed to sustain two growing radicals (about 13,000 Å), after which it increased to 3. The present work uses more recent particle-growth theories to demonstrate that these experimental values of 2.5 and 3 are consistent with the theoretical predictions for water-soluble and oil-soluble initiators, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1973.170110211
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  • 16
    Electronic Resource
    Electronic Resource
    Thermal treatment, spectroscopic analyses, and electrical properties of poly(copper 2,3,9,10,16,17,23,24-octacyanophthalocyanine) (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 23 (1985), S. 1589-1597 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thermal treatment of novel poly(copper 2,3,9,10,16,17,23,24-octacyanophthalocyanine), PCOCP, has been carried out at different temperatures in an inert atmosphere. As polyacrylonitrile, the polymer can be thermally cyclized through the cyano groups to produce semiconductive and conductive materials. Polymeric copper octacyanophthalocyanine material with a conductivity as high as 5-8 (Ω cm)-1 was prepared. Weight loss, electrical data, infrared, and photoacoustic results of the thermally treated copper octacyanophthalocyanine polymer are discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.170230529
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  • 17
    Electronic Resource
    Electronic Resource
    Structure-property relationships in polycaprolactone-polyurethanes (1983)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 21 (1983), S. 65-95 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The structure-property relationships of polycaprolactone-based segmented polyurethanes were studied using differential scanning calorimetry (DSC), small-angle x-ray scattering (SAXS), wide-angle x-ray diffraction (WAXD), dynamic mechanical, and stress-strain testing. The materials studied varied in hard-segment type [4,4′-diphenylmethane diisocyanate/butanediol (MDI/BD) or 4,4′-dicyclohexyl methane diisocyanate/butanediol (H12MDI/BD)], soft-segment molecular weight (830 or 2000 MW polycaprolactone), hard-segment content (23-77% by weight), and thermal history. The materials with aromatic (MDI/BD) hard segments had semicrystalline hard-segment domains, while the materials with aliphatic (H12MDI/BD) hard segment had mostly amorphous domains. Materials with the shorter polycaprolactone soft segment (830 MW) exhibited thermal and mechanical behavior which indicated a considerable degree of hard- and soft-segment compatibility. The materials which contained a 2000-MW polycaprolactone soft segment exhibited better-defined microphase separation. SAXS was used to characterize the microphase structure of each system. The effects of hard-segment content and soft-segment molecular weight were similar for the aromatic (MDI) and aliphatic (H12MDI) hard-segment-based block copolymers. Changing the hard segment from aromatic to aliphatic gave materials with larger interfacial area and slightly higher tensile strength. A range of morphologies between isolated hard domains in a rubbery matrix and isolated rubbery domains in a hard matrix was observed.
    Additional Material: 19 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1983.180210106
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  • 18
    Electronic Resource
    Electronic Resource
    Polymerization of tetrahydrofuran: A radiochemical study of the initiation mechanism (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 7 (1969), S. 1489-1496 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 14C-tagged triphenylmethyl hexachloroantimonate was used to initiate the polymerization of THF. An activity count on the polymers indicated no incorporation of initiator fragments into the macromolecule. On ascertaining the fate of the tagged trityl fragment it was found that the activity resided in the triphenylmethane isolated from the methanol supernatant. This indicates that at least one sequence of the initiation reaction in this polymerization involves hydride ion abstraction.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.150070612
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