Consequences of the Excited Volume Effect on the Rate of Reactions Involving Two Randomly Coiled Polymer Chains. II. Hydrolysis of Phenyl Ester Groups in Side Chains of Acrylamide Copolymers in the Presence of Acrylamide Copolymers Carrying Pyridine Residues

1973 ◽  
Vol 6 (4) ◽  
pp. 628-631 ◽  
Author(s):  
June-Ru Cho ◽  
Herbert Morawetz
Keyword(s):  
Volume Effect ◽  
Polymer Chains ◽  
Side Chains ◽  
Phenyl Ester ◽  
Hydrolysis Of ◽  
Acrylamide Copolymers

Model of a folded polypeptide chain

1950 ◽  
Vol 137 (886) ◽  
pp. 79-79
Keyword(s):  
Amino Acid ◽  
Polypeptide Chain ◽  
Molecular Model ◽  
Polymer Chains ◽  
Side Chains ◽  
Amino Acid Residues ◽  
Infra Red ◽  
New Type ◽  
Folded Proteins ◽  
Red Radiation

The models on view in the ante-room show a way of folding a polypeptide chain which is consistent with some observations we have recently made with polarized infra-red radiation (Ambrose & Hanby 1949; Ambrose, Elliott & Temple 1949). The α -folded proteins, keratin, myosin and tropomyosin, have been found when oriented to show greater absorption of the N-H frequency when the electric vector of the absorbed radiation is in the direction of the fibre axis, hence the N-H bond must be preferentially oriented in this direction. A study of models has suggested that the only likely folding of the polypeptide chain consistent with this fact involves a seven-membered ring containing two amino-acid residues; the ring is completed by hydrogen bonds: A new type of atomic model which has been developed in our laboratories has been used. The scale is 0·8 in. to the Angstrom unit. The valency links, while allowing free rotation about single co-valent bonds, also allow some distortion of the bond angles when strains occur but are strong enough to allow long polymer chains to be built. The molecular model exhibited shows twenty-four amino-acid residues, with side chains on one side of the back-bone, representative of those occurring in myosin; the side chains on the other side have been removed for clearness and their positions indicated by single carbon atoms.

The effect of excluded volume on polymer dispersant action

1975 ◽  
Vol 343 (1635) ◽  
pp. 427-442 ◽  
Keyword(s):  
Free Energy ◽  
High Surface ◽  
Volume Effect ◽  
Polymer Chains ◽  
Excluded Volume ◽  
Density Distributions ◽  
Excluded Volume Effects ◽  
Adsorbed Polymer ◽  
Polymer Distribution ◽  
Dimensional Equation

Polymer-stabilized colloid particles are modelled theoretically by plane surfaces on to which polymer chains are adsorbed by one end only. Interactions between segments of the polymer are treated as an excluded volume effect. It is shown that for high surface densities the polymer distribution function exactly satisfies a one dimensional equation which is solved numerically for two values of excluded volume to give the polymer segment density distributions and the free energy of interaction for various separations of the plane surfaces. It is found that a positive value of excluded volume greatly increases the repulsive free energy compared with that for chains with zero excluded volume, particularly at large separation distances of the surfaces. Excluded volume effects must therefore play an important part in the stabilization of colloids by adsorbed polymer.

Polymer Effects under Pressure. 2. Enzymelike Catalysis in the Hydrolysis of Phenyl Ester by Copolymer Containing Imidazole

1978 ◽  
Vol 11 (4) ◽  
pp. 829-832 ◽  
Author(s):  
Yoshihiro Taniguchi ◽  
Kiyokazu Shimokawa ◽  
Hideo Hisatome ◽  
Shyoichi Tanamachi ◽  
Keizo Suzuki
Keyword(s):  
Phenyl Ester ◽  
Hydrolysis Of

Hydrolysis of polyacrylamide and acrylic acid-acrylamide copolymers at neutral pH and high temperature

Polymer ◽  
1988 ◽  
Vol 29 (5) ◽  
pp. 860-870 ◽  
Author(s):  
Houchang Kheradmand ◽  
Jeanne François ◽  
Véronique Plazanet
Keyword(s):  
High Temperature ◽  
Acrylic Acid ◽  
Neutral Ph ◽  
Hydrolysis Of ◽  
Acrylamide Copolymers

scholarly journals Excluded-Volume Effect on Dipole Moments of Polymer Chains

1971 ◽  
Vol 2 (3) ◽  
pp. 416-421 ◽  
Author(s):  
Kazuo Nagai ◽  
Toshihide Ishikawa
Keyword(s):  
Dipole Moments ◽  
Volume Effect ◽  
Polymer Chains ◽  
Excluded Volume ◽  
Excluded Volume Effect

scholarly journals Novel insight in carbohydrate degradation during alkaline treatment

Holzforschung ◽  
2015 ◽  
Vol 69 (6) ◽  
pp. 667-675 ◽  
Author(s):  
Kaarlo Nieminen ◽  
Lidia Testova ◽  
Markus Paananen ◽  
Herbert Sixta
Keyword(s):  
Chain Length ◽  
Alkaline Hydrolysis ◽  
Alkaline Treatment ◽  
Polymer Chains ◽  
Alkaline Media ◽  
Parameter Estimates ◽  
Reaction Rate Constants ◽  
Carbohydrate Degradation ◽  
The Impact ◽  
Hydrolysis Of

Abstract A mathematical model is presented, in which the yield loss (YL) and the decline in polymerization of carbohydrates is comprehended. The model is applicable to the treatment of cellulose and hemicelluloses in alkaline media, and it features the actions of peeling, stopping, and alkaline hydrolysis of the polymer chains. The peeling reaction is further subdivided into primary and secondary peeling depending on whether it originates from an initial reducing end-group (REG) or from an REG created by alkaline hydrolysis. Fitting the model to experimental data provides estimates of the various reaction rate constants. When available, simultaneous observations of the YL and the decrease in chain length contribute to the evaluation of the parameters. Alternatively, if the data are limited to the YL, the obtained parameter estimates allow for a projection of the time development of chain length. The model has been applied on data from two types of experiments: soda-anthraquinone treatment of cotton linters and kraft treatment of Scots pine. It was possible to evaluate the impact of the different processes on degradation as well as the portions of polymer chains possessing active or stabilized REGs.

STUDIES ON REACTIONS RELATING TO CARBOHYDRATES AND POLYSACCHARIDES: LIII. STRUCTURE OF THE DEXTRAN SYNTHESIZED BY THE ACTION OF LEUCONOSTOC MESENTERIOIDES ON SUCROSE

1937 ◽  
Vol 15b (11) ◽  
pp. 486-497 ◽  
Author(s):  
Frances L. Fowler ◽  
Irene K. Buckland ◽  
Fritz Brauns ◽  
Harold Hibbert
Keyword(s):  
Hydrochloric Acid ◽  
Linear Chain ◽  
Chemical Investigation ◽  
Side Chain ◽  
Side Chains ◽  
Methyl Glucoside ◽  
Antigenic Properties ◽  
Hydrolysis Of

The dextran synthesized from sucrose by the action of one strain of Leuconostoc mesenterioides has been subjected to chemical investigation. The polysaccharide has been hydrolyzed to glucose. The triacetate, tribenzoate, and trimethyl derivative (all calculated on a glucose anhydride unit) have been prepared. Hydrolysis of trimethyl dextran by the action of methanol-hydrochloric acid yielded dimethyl, trimethyl, and tetramethyl methyl glucosides in the ratio of 1: 3: 1. The products of hydrolysis have been identified as 2,3-dimethyl methyl glucoside, 2,3,4-trimethyl methyl glucoside, and 2,3,4,6-tetramethyl methyl glucoside.The results indicate that dextran is a polymer of a pentaglucopyranose anhydride. One of the glucopyranose units is attached as a side chain, the remaining four being most probably connected in linear chain union. Three of the linkages between building units are of the 1,6 type, while the remaining two are either 1,4 or 1,6.The antigenic properties shown by dextran are probably a result of the presence of the glucose side chains.

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