ChemInform Abstract: ALKALINE POLYMERIZATION OF 6-CAPROLACTAM PART 48, FRACTION OF ACYL GROUPS OF THE ACTIVATOR INCORPORATED IN A HIGH-MOLECULAR WEIGHT POLYMER PART 49, EFFECT OF THE ACTIVATOR/INITIATOR RATIO ON THE MOLECULAR WEIGHT DISTRIBUTION

1973 ◽  
Vol 4 (46) ◽  
pp. no-no
Author(s):  
J. STEHLICEK ◽  
J. EXNER ◽  
P. CEFELIN ◽  
J. SEBENDA ◽  
M. KAPUSCINSKA ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer ◽  
Polymer Part

scholarly journals Effects of Illuminance and Heat Rays on Photo-Controlled/Living Radical Polymerization Mediated by 4-Methoxy-2,2,6,6-Tetramethylpiperidine-1-Oxyl

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Eri Yoshida
Keyword(s):  
Molecular Weight ◽  
Radical Polymerization ◽  
Light Source ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Bulk Polymerization ◽  
Living Radical Polymerization ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer ◽  
Controlled Living Radical Polymerization

The effects of illuminance and heat rays released from the light source on the photo-controlled/living radical polymerization of methyl methacrylate were investigated with the aim of strict control of molecular weight. The bulk polymerization was performed at room temperature using 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl as the mediator and (2RS,RS)-azobis(4-methoxy-2,4-dimethylvaleronitrile) as the initiator in the presence of (4-tert-butylphenyl)diphenylsulfonium triflate as the accelerator by irradiation with a high-pressure mercury lamp. The polymerization by the direct irradiation from the light source yielded polymers containing an uncontrolled high-molecular-weight polymer and having the molecular weight distribution over 3. On the other hand, the polymerization by the indirect irradiation with reflective light using a mirror produced polymers with controlled molecular weights with comparatively narrow molecular weight distribution at ca. 1.4. Too high an illuminance caused an increase in the molecular weight distribution. During the polymerization, the monomer conversion increased as the illuminance increased. It was found that the elimination of heat rays from the illuminating light was indispensable for the molecular weight control by the photo-controlled/living radical polymerization.

Intrinsic viscoelasticity in thin high-molecular-weight polymer films

2014 ◽  
Vol 89 (6) ◽  
Author(s):  
Xiaoyuan Sheng ◽  
Frédéric Wintzenrieth ◽  
Katherine R. Thomas ◽  
Ullrich Steiner
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Polymer Films ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer

Structural studies of the capsular polysaccharide from Haemophilus pleuropneumoniae serotype 2

1987 ◽  
Vol 65 (5) ◽  
pp. 414-422 ◽  
Author(s):  
Eleonora Altman ◽  
Jean-Robert Brisson ◽  
Malcolm B. Perry
Keyword(s):  
Molecular Weight ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
High Molecular Weight ◽  
Capsular Polysaccharide ◽  
Structural Studies ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer ◽  
Structure Formula ◽  
Nuclear Magnetic

The capsular polysaccharide of Haemophilus pleuropneumoniae serotype 2 (ATCC 27089) is composed of D-glucose (two parts), D-galactose (one part), glycerol (one part), and phosphate (one part). Hydrolysis, dephosphorylation, methylation, enzymic studies, and 1H and 13C nuclear magnetic resonance experiments showed that the polysaccharide is a high molecular weight polymer of a tetrasaccharide repeating units, linked by monophosphate diester and having the following structure:[Formula: see text]

scholarly journals Antigen valence determines the binding of nominal antigen to cytolytic T cell clones.

1985 ◽  
Vol 162 (2) ◽  
pp. 768-773 ◽  
Author(s):  
R F Siliciano ◽  
R M Colello ◽  
A D Keegan ◽  
R Z Dintzis ◽  
H M Dintzis ◽  
...  
Keyword(s):  
Molecular Weight ◽  
T Cell ◽  
High Molecular Weight ◽  
Cytotoxic T Cell ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer ◽  
T Cell Clones ◽  
Cell Clones ◽  
Nominal Antigen ◽  
Epitope Density

We have shown that cytotoxic T cell clones specific for the nominal antigen FL will bind high molecular weight (600,000 to 2,000,000) polyacrylamide and Ficoll polymers conjugated with 200-600 FL groups per molecule. Low molecular weight polymers (40,000) with the same epitope density did not give stable binding. A high molecular weight polymer with a lower epitope density also failed to bind. Taken together, these results suggest that a substantial degree of multivalence is a necessary factor in the stable binding of nominal antigen to T cell clones.

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