Polymers natural or synthetic

Synthetics are made up of polymers—natural or synthetic compounds of high molecular weight. Different polymeric materials may be used in the construction of FMLs26,27 ... 

Polymers, natural or synthetic, are characterized by an extended chain structure. Giant molecules called macromolecules are formed by joining the chain elements in different ways. Each unit or building block of the chain is called a monomer and a polymer results when we join many monomers to form a chain. We describe below some important classes of polymers, their structure, and some of their important attributes. 

Microparticles are defined as particles with a size ranging from 1 pm to 1 mm, and whose main component is a polymer, natural or synthetic. 

Self-organization of macromolecules is one of the most popular way to achieve nanostructured features because it can be in principle applied to every kind of polymer, natural or synthetic [8], The recent advances in design criteria for the attainment of well-defined polymers and nanostructures allow to produce macromolecules with specific functionalities which are tailored for potentials in development of capsules, drug delivery systems and nanoscale electro-optical devices [9], Upon this premise, the methods that are able to induce the self-assembly of macromolecules are related to the chemico-physical properties of the selected polymer, of the substrate on which the nanostructure grows and on their combination. Obviously, this premise envisages the variety of different morphologies, nanostructures and related applications that can be obtained by the versatility of self-assembly. 

These are high molecular weight polymers, natural or synthetic such as xanthan gum, hydroxyethyl cellulose, alginates, carrageenans, etc. To understand the role of these thickeners , let us consider the gravitational stresses exerted during creaming or sedimentation,... 

Polymer— natural or synthetic compoimds of high molecirlar weight and made of repeated lirrked units. 

To date, many biochemical and molecular biological studies have been performed on the degradation of polymers, natural or synthetic. Our work, however, is unique in that we aim to clarify not only the enzymes and genes involved in degradation, but also the regulation of genes by macromolecules (non-penetrable into cells). We also aim to clarify how and where macromolecules are degraded to enter the central metabolic pathway. 

Fibers for commercial and domestic use are broadly classified as natural or synthetic. The natural fibers are vegetable, animal, or mineral ia origin. Vegetable fibers, as the name implies, are derived from plants. The principal chemical component ia plants is cellulose, and therefore they are also referred to as ceUulosic fibers. The fibers are usually bound by a natural phenoHc polymer, lignin, which also is frequentiy present ia the cell wall of the fiber thus vegetable fibers are also often referred to as lignocellulosic fibers, except for cotton which does not contain lignin. 

Organic Flocculants. The organic flocculants are all water-soluble natural or synthetic polymers. 

Pretreatment Chemicals Even though the suspended solids concentration of the slurry to be tested may be correct, it is frequently necessary to modify the sluriy in order to provide an acceptable filtration rate, washing rate, or final cake moisture content. The most common treatment, and one which may provide improvement in all three of these categories, is the addition of flocculating agents, either inorganic chemicals or natural or synthetic polymers. The main task at this point is to determine which is the most effective chemical and the quantity of chemical which should be used. 

It may also be mentioned that a number of commercial polymers are produced by chemical modification of other polymers, either natural or synthetic. Examples are cellulose acetate from the naturally occurring polymer cellulose, poly(vinyl alcohol) from polyfvinyl acetate) and chlorosulphonated polyethylene (Hypalon) from polyethylene. 

The polymers used for completion and workover fluids may be either natural or synthetic polymers. Guar gum is a natural polymer that swells on contact with water and thus provides viscosity and filtration control it is used in concentrations of 1 to 3 Ib/bbl. Guar gum forms a filter cake that may create... 

The term s plastic, polymer, resin, elastomer, and reinforced plastic (RP) are some-what synonymous. However, polymer and resin usually denote the basic material. Whereas plastic pertains to polymers or resins containing additives, fillers, and/or reinforcements. Recognize that practically all materials worldwide contain some type of additive or ingredient. An elastomer is a rubberlike material (natural or synthetic). Reinforced plastics (also called composites although to be more accurate called plastic composites) are plastics with reinforcing additives, such as fibers and whiskers, added principally to increase the product s mechanical properties. 

Depending on their origin, it is possible to group polymers as natural or synthetic. 

Dry strength additives are usually water soluble, hydrophilic natural or synthetic polymers, the commercially most important of which are starch, natural vegetable gums and polyacrylamides. These polymers are often made in cationic form by the introduction of tertiary or quaternary amino groups into the polymer, and are therefore polyelectrolytes. They are thus also able to function to some extent as drainage and retention aids. 

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