β-Glycosylamide Glycopolymers: Synthesis, Physical Properties, Chemical and Enzymatic Stability

1995 ◽  
Vol 394 ◽  
Author(s):  
Wayne Spevak ◽  
Frangois D. Tropper
Keyword(s):  
Molecular Weight ◽  
Physical Properties ◽  
Water Soluble ◽  
Glycosidic Linkage ◽  
Water Soluble Polymers ◽  
Soluble Polymers ◽  
Enzymatic Stability ◽  
Reducing Carbohydrates

AbstractA method is described for the preparation β-glycosylamide monomers from reducing carbohydrates. The glycosylamide monomers were copolymerized with acrylamide to formhigh molecular weight, water soluble polymers. The chemical and enzymatic stability of the β-N-glycosidic linkage was investigated. In addition, the glycopolymers were characterized by their interactions with lectins.

Chemical Characterization Problems of Water-Soluble Polymers

1981 ◽  
Vol 21 (06) ◽  
pp. 721-730 ◽  
Author(s):  
D.A. Tyssee ◽  
O.J. Vetter
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Water Soluble ◽  
Polymer Chemistry ◽  
Petroleum Reservoir ◽  
Polymer Backbone ◽  
Water Soluble Polymers ◽  
Soluble Polymers ◽  
The Past ◽  
Analytical Procedures

Abstract Water-soluble polymers are being used increasingly in oil, gas, and geothermal production. Applications include drilling, stimulation, workover and completion, and reservoir flooding fluids. The development of polymers and their application has been mostly empirical. Such a course of development was suitable in the past. However, empirical techniques do not satisfy present and future needs which include (1) the cost/performance relationship and (2) environmental effects associated with expanding polymer application. Therefore, a more thorough understanding of the polymer chemistry is required.The first step in doing this is to develop laboratory methods to characterize these complex materials and their degradation products. The problems are (1) understanding polymer chemistry under field conditions and (2) developing analytical procedures. These problems emerged dramatically during analysis of recent fracture stimulation of some geothermal wells. An involved study of the potential analytical methods was conducted. Polysaccharides were used for the actual field fracture jobs as well as for the analytical procedures. Correlations were made between the total organic content and carbohydrate content of the return waters as a function of residence time under simulated reservoir conditions. Preliminary indications are that more sophisticated information can be obtained by the use of emerging analytical techniques such as high pressure liquid chromatography (HPLC).Advantages gained from use of these methods and others are discussed. Introduction A variety of polymers are used in the petroleum industry for drilling, workover, and completion fluids. Many of these polymers can be used in the geothermal industry for similar applications. However, because the environment of a geothermal reservoir may be drastically different from that of a petroleum reservoir, it is critical that these polymers be investigated under conditions that simulate geothermal environments. In the past, physical property measurements of aqueous solutions of these polymers have been emphasized - particularly fluid rheology both for petroleum and, to a lesser extent, geothermal applications. These physical properties, which are valuable in selecting polymers or polymer blends for use, can be related to the chemical properties of the polymers. Properties such as molecular weight distribution and macrostructure, molecular conformation, side-chain structure, composition of the monomer units comprising the polymer backbone, chemical interactions in the make-up water, chemical and thermal stability, etc., play an important role in determining the ultimate physical properties of the polymer in solutions.Many of these chemical features have been overlooked, and the development of polymers for field applications has followed a strictly empirical course. This empiricism has led to a great deal of confusion when polymers must be selected for field use. A more serious drawback has been the lack of new polymer types - largely because little is known about how the physical properties desired can be related to polymer chemistry. This can be traced for the most part to the lack of chemical methods available in the past to characterize the polymers chemically in sufficient detail. The high-temperature requirements of geothermal applications impose severe limitation on the fracture polymers, particularly their performance and chemical stability under high-temperature conditions. SPEJ P. 721^

scholarly journals Macromolecular Systems for Vaccine Delivery

2016 ◽  
pp. S203-S216 ◽  
Author(s):  
G. MUŽÍKOVÁ ◽  
R. LAGA
Keyword(s):  
Molecular Weight ◽  
Infectious Diseases ◽  
Human Medicine ◽  
Water Soluble ◽  
Water Soluble Polymers ◽  
Soluble Polymers ◽  
Cell Responses ◽  
Macromolecular Systems ◽  
Protective Antibodies ◽  
Life Threatening

Vaccines have helped considerably in eliminating some life-threatening infectious diseases in past two hundred years. Recently, human medicine has focused on vaccination against some of the world’s most common infectious diseases (AIDS, malaria, tuberculosis, etc.), and vaccination is also gaining popularity in the treatment of cancer or autoimmune diseases. The major limitation of current vaccines lies in their poor ability to generate a sufficient level of protective antibodies and T cell responses against diseases such as HIV, malaria, tuberculosis and cancers. Among the promising vaccination systems that could improve the potency of weakly immunogenic vaccines belong macromolecular carriers (water soluble polymers, polymer particels, micelles, gels etc.) conjugated with antigens and immunistumulatory molecules. The size, architecture, and the composition of the high molecular-weight carrier can significantly improve the vaccine efficiency. This review includes the most recently developed (bio)polymer-based vaccines reported in the literature.

Novel Drag-Reducing Agents for Fracturing Treatments Based on Polyacrylamide Containing Weak Labile Links in the Polymer Backbone

SPE Journal ◽  
2012 ◽  
Vol 17 (03) ◽  
pp. 924-930 ◽  
Author(s):  
E.. Kot ◽  
R.K.. K. Saini ◽  
L.R.. R. Norman ◽  
A.. Bismarck
Keyword(s):  
Molecular Weight ◽  
Oil And Gas ◽  
Elevated Temperatures ◽  
Reducing Agents ◽  
Reducing Agent ◽  
Water Soluble ◽  
Weak Links ◽  
Polymer Backbone ◽  
Water Soluble Polymers ◽  
Soluble Polymers

Summary Water-soluble polymers have found extensive use in the oil and gas industry. For instance, high-molecular-weight polymers are very efficient drag-/friction-reducing agents and viscosifiers. Unfortunately, the adsorption of the polymer on the reservoir formation reduces the effectiveness of the recovery of oil and gas from low-permeability formations, such as shale. The availability of water-soluble polymers containing weak links in the backbone of the polymer that can be degraded upon experiencing a certain trigger, such as temperature, pH, or reducing agent, would be very advantageous. Because of the ability of weak links to degrade under certain conditions, such polymers can be used for their intended application and can afterward be degraded in a controlled and predetermined way. The resulting lower-molecular-weight fractions of that polymer lead to a reduced viscosity and quick partitioning into the water phase, and they are also less likely to adsorb onto formation surfaces. Additionally, no oxidizers need to be pumped to break or clean the deposited polymer, thus saving treatment time. It has been proved that using a bifunctional reducing agent containing degradable groups and oxidizing metal ions as a redox couple is an effective method to initiate free-radical polymerization and build degradable groups into the backbone of vinyl polymers. Temperature-degradable but hydrolytically stable azo groups showed the most-desirable results. The presence of azo groups in the backbone of the synthesized polyacrylamide (PAM) was confirmed by H1-NMR spectra and differential scanning calorimetry (DSC). The degradation behavior of the PAM with temperature-sensitive azo groups was characterized using gel permeation chromatography (GPC) and proved that multiple labile links were built into the polymer backbone. It was also found that PAM with azo links in the polymer backbone is as good a drag-reducing agent as pure PAM. However, PAM with azo links in the backbone loses its drag-reduction properties once subjected to elevated temperatures, which for some applications is viewed as an advantage.

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