Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Polymer and Materials Science  (6)
  • Polymeremulsion  (4)
  • 1
    ISSN: 1435-1536
    Keywords: Polymeremulsion ; polymermicrosphere ; XPSanalysis ; styrene ; 2-hydroxyethylmethacrylate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Polymer microspheres composed of various compositions of styrene and 2-hydroxyethyl methacrylate (HEMA) were produced by batch emulsifier-free emulsion polymerization. The HEMA content at the surface, [HEMA] s , of the microspheres powdered by freeze-drying was determined by both quantitativeC 1s /O 1s analysis andC 1s peak shape analysis of the x-ray photoelectron spectroscopic spectra. When the HEMA content in the microsphere, [HEMA] p , was less than about 5 mole%, the [HEMA] s values determined by the two different methods showed good agreement. At [HEMA]p above 5 mole %, [HEMA]s values determined by the first method were about 15 mole % greater than those determined by the second. They both showed a similar tendency with the [HEMA] s being higher than the [HEMA] p , e.g., when [HEMA] p was 1 mole %, [HEMA] s was 11 mole %. The intensity of the satellite peak due to theπ→π * transition of the benzene ring of the styrene component decreased with an increase in [HEMA] p , to zero at 5 mole % of [HEMA] p . These results indicate that the HEMA component is localized at the surface.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 269 (1991), S. 1126-1132 
    ISSN: 1435-1536
    Keywords: Polymeremulsion ; microsphere ; vinylgroup ; brominetitration ; dispersionpolymerization ; seededpolymerization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The distribution of vinyl groups in polystyrene/poly(styrene-divinylbenzene) (PS/P(S-DVB)) composite microspheres produced by seeded copolymerization of S and DVB in the presence of 2.1-μm monodisperse PS seed particles was estimated from the amount detected with bromine titration method as a function of the reaction time under various conditions.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1435-1536
    Keywords: Polymeremulsion ; polymermicrosphhere ; bovineserumalbumin ; proteinadsurption ; surfacehydrophilicity ; surfaceheterogeneity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The adsorption behaviors of bovine serum albumin (BSA) containing both dimeric and monomeric species onto polymer microspheres were examined using various homopolymers and poly(2-hydroxyethyl methacrylate)/polystyrene composite microspheres which were produced by the emulsifier-free (seeded) emulsion polymerization technique. The preferential adsorption of the BSA dimer was clearly observed in an optimum region of the surface hydrophilicities of the polymer microspheres. The preferential adsorption of the BSA dimer onto the composite polymer microspheres having heterogeneous surfaces consisting of hydrophilic and hydrophobic parts was more marked than those onto the homopolymer and copolymer microspheres having homogeneous surfaces.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 270 (1992), S. 733-737 
    ISSN: 1435-1536
    Keywords: Polymeremulsion ; microsphere ; chloromethylgroup ; polyamine ; cationicgroup ; dispersionpolymerization ; seededpolymerization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Micron-size monodisperse crosslinked polymer microspheres having chloromethyl groups were prepared by seeded copolymerization of styrene, divinylbenzene, and chloromethylstyrene in the presence of 2.1-μ monodisperse polystyrene seed particles produced by dispersion polymerization. The modification reaction of chloromethyl groups on the surfaces with polyamines such as triethylenetetramine and ethylenediamine was carried out. From the measurements of ξ potential and the amount of chloride ion released, the introduction of a large number of cationic groups at the surfaces was confirmed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 28 (1983), S. 3671-3679 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The novel reactive antioxidants based on tetrazoles that are stable at room temperature and convertible into the highly reactive nitrileimines by pyrolysis were prepared and the reactivity for carbon-carbon double bonds was evaluated. Antioxidants, i.e., 2-substituted phenyl-5-(3′,5′-di-tert-butyl-4′-hydroxyphenyl)tetrazoles (PHPT) were prepared with the reaction of p-toluenesulfonylhydrazone of 3,5-di-tert-butyl-4-hydroxybenzaldehyde and substituted phenyl diazonium chloride in a mixed solvent of pyridine, ethanol, and water at -10°C to -20°C in 31-61% yields. To evaluate the reactivities of PHPT for carbon-carbon double bonds, m-chloro-substituted PHPT was pyrolyzed in an excess of styrene at 160-170°C for 0.5 h to give the 1-(3′-chlorophenyl)-3-(3″,5″-di-tert-butyl-4″-hydroxyphenyl)-5-phenyl-2-pyridazoline in a 44.1% yield by 1,3-dipolar addition reaction of the nitrileimine formed from the m-chloro-substituted PHPT. The thermogravimetric analysis of a mixture of proton isomer of PHPT and liquid polybutadiene showed that PHPT attached to liquid polybutadiene with an accompanying evolution of nitrogen.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 29 (1984), S. 89-98 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The chemical reactivities of novel reactive antioxidants based on tetrazoles for carbon-carbon double bonds of liquid polybutadiene and their antioxidation activities toward isoprene rubber were evaluated. These antioxidants, i.e., 2-substituted phenyl-5-(3′,5′ -di-tert-butyl-4′-hydroxyphenyl)tetrazoles (PHPT), were pyrolyzed in liquid polybutadiene at 160-170°C for 30 min to attach to rubber in extents of 61-85% of the nitrileimines formed from PHPT by 1,3-dipolar addition reaction. The reactivities of PHPT followed the order p-Cl 〉 m-Cl 〉 H 〉 p-CH3 〉 m-CH3, p-OC2H5, suggesting that PHPT reacts with diene rubber in electrophilic reaction and p-derivatives exhibit higher contents of binding than m-derivatives due to steric hindrance. From oxygen absorption data, the antioxidation activities of PHPT for isoprene rubber vulcanizates followed the order m-Cl, m-CH3 〉 H, p-Cl, p-Cl, p-CH3 〉 p-OC2H5. Isoprene rubber vulcanizates, obtained after pretreatment with PHPT by heating, were extracted with acetone, followed by aging to show that there was good retention and appreciable antioxidation activities of PHPT, especially, p-CH3 and p-Cl substituted PHPT.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 30 (1985), S. 4201-4201 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 29 (1991), S. 1197-1202 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Monodisperse microspheres of poly(diethylene glycol dimethacrylate) with diameters in the size range 0.4-4.8 μm were prepared by the radiation-induced polymerization. Effects of solvent viscosity and monomer solubility were investigated for various kinds of solvents. The number of the nuclei, produced in the early stage of the polymerization, was found to be constant during the remainder of the polymerization. The nuclei grow to be monodisperse polymer particles without aggregation. This is attributed to the low mobility of the growing polymer particles.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 61 (1996), S. 351-358 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The amine functionalization of an acrylamide copolymer was achieved via Hofmann degradation. The starting material, poly(acrylamide-co-methyl methacrylate), was synthesized by radical precipitation polymerization. Using this copolymer, Hofmann degradation at 0°C in a water-dioxane mixture was done using sodium hypochlorite and NaOH. The resulting hydrogel could be dissolved in water-tetrahydrofuran mixtures, and the cast film had a water content of 73%. It was found that the conversion to primary amine was lower, and the extent of a side reaction was higher, compared to those of an acrylamide homopolymer. This was presumed to be due to the lack of the neighboring group effect among acrylamide units since it was a random copolymer. Further modification of this polymer by reacting the amine group is considered to obtain the desired properties for biomedical applications. © 1996 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 13 (1985), S. 191-202 
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Recently there has been a growth of interest in the use of diaryliodonium salts (Ar2I+X-), triarylsulfonium salts (Ar3S+X-) and triarylselenonium salts (Ar3Se+X-) as photochemical initiator for cationic polymerizations. It is suggested by Ledwith that electron transfer to these cations results in fragmentation with the formation of aryl radicals and if the reducing species is a suitable free radical, a chain reaction for formation of cation will occur.We carried out radiation-induced polymerization of α-methyl-styrene in dichloromethane and bulk cyclohexene oxide in the presence of triphenyliodonium salt (C6H5)2 (I+PF-). Polymerization of these monomers was observed in the presence of these salts (G(-M)⋍ 1300), while no polymer was obtained in the absence of salts. Postpolymerization was negligibly small. This polymerization is considered to be initiated by the reaction of free radicals produced by radiation with cation salts and to proceed by cationic mechanism, since α-methylstyrene polymerized by ionic mechanism but hardly polymerizes by radical mechanism and this polymerization was suppressed in the presence of a small amount of water. The initiation mechanism of this polymerization was investigated by the use of pulse radiolysis technique.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...