Microstructural Analysis of Paste and Interfacial Transition Zone in Cement Mortars Modified with Water-Soluble Polymers

2011 ◽  
Vol 466 ◽  
pp. 21-28 ◽  
Author(s):  
Elke Knapen ◽  
Dionys Van Gemert
Keyword(s):  
Transition Zone ◽  
Cement Mortar ◽  
Microstructural Analysis ◽  
Interfacial Transition Zone ◽  
Water Soluble ◽  
Water Soluble Polymers ◽  
Soluble Polymers ◽  
Cement Mortars ◽  
The Matrix ◽  
Mixing Water

The presence of water-soluble polymers affects the microstructure of polymermodified cement mortar. Such effects are studied by means of SEM investigation. Polyvinyl alcohol-acetate (PVAA), Methylcellulose (MC) and Hydroxyethylcellulose (HEC) are applied in a 1 % polymer-cement ratio. The polymers provide an improved dispersion of the cement particles in the mixing water. The tendency of certain water-soluble polymers to retard the flocculation of the cement particles minimizes the formation of a water-rich layer around the aggregate surfaces. They also provide a more uniform distribution of unhydrated cement particles in the matrix, without significant depletion near aggregate surfaces. Both effects enable to reduce the interfacial transition zone (ITZ). The polymers also provide a more cohesive microstructure, with a reduced amount of microcracks.

TYPES OF CHITOZAN MODIFICATION BY USING VARIOUS DERIVATIVE AGENTS

2021 ◽  
pp. 23-30
Author(s):  
Pyatigorskaya N.V. ◽  
Kargin V.S. ◽  
Brkich G.E.
Keyword(s):  
Biological Properties ◽  
Water Soluble ◽  
Patent Data ◽  
Water Soluble Polymers ◽  
Soluble Polymers ◽  
Modified Chitosan ◽  
The Matrix ◽  
Low Toxicity ◽  
Dissolved Form ◽  
Salt Forms

The prevalence of the study of chitosan is associated with favorable biological properties of the polymer: low toxicity, biodegradability, and biocompatibility with cells of the human body. Chitosan is a complex aminopolysaccharide consisting of two types of monosaccharaides: 2-acetamide-D-glucose and 2-amino-D-glucose connected by a 1,4-β-glycosidic bond, obtained by chitosan by chitin deacetylation. Chitosan has hemostatic, hypolipedymic and antimicrobial activity against gram-positive and gram-negative microorganisms. However, the preparation of various drugs based on it is accompanied by difficulties in the development of biodegradable compositions that are related to the field of application. For the immobilization of various compounds used as drugs for the treatment of complications associated with damage to the skin, it is possible to use chitosan in dissolved form, converted into a salt form. However, salt forms of chitosan are water-soluble polymers, which leads to the rapid degradation of the matrix and the release of the drug from it, due to hydrophilicity. Additional lipophilization is required to obtain insoluble chitosan structures. Therefore, various modified chitosan structures are used that have suitable properties for the manufacture of a medicament. In addition, lipophilization of the chitosan structure allows the immobilization of more lipophilic structures. The purpose of this work was to study the literature and patent data sources for conducting information-analytical search of the approach. That led to the choice of a modified chitosan structure for its use in the pharmaceutical development of finished dosage forms. The article considers various types of derivatizing agents and the properties of modified chitosan structures.

Influence of Polyelectrolytes on the Processes of Structure Formation of Copper Powders

2020 ◽  
Vol 299 ◽  
pp. 1069-1074
Author(s):  
Yu.M. Berezhnoi ◽  
D.I. Monastyrsky ◽  
O.N. Romanova
Keyword(s):  
Particle Growth ◽  
Water Soluble ◽  
Growth Inhibitors ◽  
Water Soluble Polymers ◽  
Soluble Polymers ◽  
Copper Powders ◽  
The Matrix ◽  
Mechanisms Of Formation ◽  
Kinetics Of ◽  
Ultrafine Copper

The results of the studies on the synthesis of ultrafine copper powders are described in the article. The mechanisms of formation of ultrafine powders, using water-soluble polyacrylamide and polyvinyl-pyrrolidone polymers, as particle growth inhibitors, are presented. The processes occurring in the presence of water-soluble polymers and their influence on the structure of the obtained ultrafine copper powders are described. The interaction of the matrix of polymer composite materials with filler particles is analyzed. The kinetics of crystallization and transformation of crystalline phases of the powder, due to the process in the presence of water-soluble polymers, as stabilizers of particle growth, are investigated.

New quenching media based on water-soluble polymers

1981 ◽  
Vol 23 (2) ◽  
pp. 104-106 ◽  
Author(s):  
A. V. Tolstousov ◽  
O. A. Bannykh
Keyword(s):  
Water Soluble ◽  
Water Soluble Polymers ◽  
Soluble Polymers ◽  
Quenching Media

scholarly journals SANS quantification of bound water in water-soluble polymers across multiple concentration regimes

Soft Matter ◽  
2021 ◽  
Author(s):  
Helen Yao ◽  
Bradley D. Olsen
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Bound Water ◽  
Water Soluble ◽  
Wide Concentration Range ◽  
Water Molecules ◽  
Water Soluble Polymers ◽  
Soluble Polymers

Small-angle neutron scattering is used to measure the number of bound water molecules associating with three polymers over a wide concentration range. Different fitting workflows are evaluated and recommended depending on the concentration regime.

scholarly journals Flow Enhancement of Water-Soluble Polymers through Porous Media by Preshearing

2021 ◽  
Author(s):  
Mohsen Mirzaie Yegane ◽  
Julia Schmidt ◽  
Fatima Dugonjic-Bilic ◽  
Benjamin Gerlach ◽  
Pouyan E. Boukany ◽  
...  
Keyword(s):  
Porous Media ◽  
Water Soluble ◽  
Water Soluble Polymers ◽  
Soluble Polymers ◽  
Flow Enhancement
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