Polymer schematic

Fig. 1.15 Intrinsic viscosity of dendrimers - compared with that of polymers (schematic) [10,30]...

Figure 2. Temperature dependence of damping and modulus for a typical polymer (schematic). (Reproduced with permission from Ref. 8. Copyright 1978 Adam Hilger Ltd.)...

Figure 4. Generalized sorption isotherm for plasticizing penetrants in glassy polymers. (Schematic.)...

Fig. 7.2 Autoxidation of polymers. Schematic representation of the oxygen uptake as a function of time. Adapted from Schnabel [24] with permission from Carl Hanser.

C, Local Penetrant Concentration in Polymer Schematic representation of typical forms for concentration-dqtendeirt diffusion coeffi-... 

Electropolymerization is typically a method used in the preparation of CPs. Electroinitiated polymerization has been used for special purposes with common vinyl monomers. Electropolymerization is, however, a stoichiometric method in which 2.1-2.7 equivalents of electricity are consumed per monomer unit. Usually electrochemical oxidation is used and the polymer is deposited on the anode. If the end monomers are not taken into account, two equivalents are needed per monomer for the bond formation. The rest is consumed for the oxidation, i.e., doping of the polymer. Schematically, the coupling reaction can be shown as in Fig. 7a. 

Keeping in mind the classification of carbohydrate polymers schematized in the Tables 1 and 2, we may now inquire where such biopolymers are found and what their functions are. 

For the multibranched polymers, an additional mechanism not considered for the linear/star-branched polymers needs to be introduced. For the simplest multibranched polymer, the pom-pom polymer schematically illustrated in Figure 16, McLdsh and Larson combined the equilibrium mechanisms (arm retraction/trunk reptation in the dynamically dilated tube) and the nonequilibrium mechanisms (arm/trunk stretch, CCR, and the arm withdrawal) to formulate a constitutive equation. The arm withdrawal mechanism, leading to partial contraction of the trunk up to a point of tension balance with the arms, is the mechanism not considered for the linear/ star-branched chains. The resulting constitutive equation for the pom-pom chains cannot be cast in a Bemstein-Zapas-Kearsley (BKZ)-type convolution form. This pom-pom con-stimtive equation reproduces the hierarchical relaxation (from... 

Fig. XI-4. Schematic diagram of the structure of an adsorbed polymer chain. Segments are distributed into trains directly attached to the surface and loops and tails extending into solution.

Figure C 1.5.13. Schematic diagram of an experimental set-up for imaging 3D single-molecule orientations. The excitation laser with either s- or p-polarization is reflected from the polymer/water boundary. Molecular fluorescence is imaged through an aberrating thin water layer, collected with an inverted microscope and imaged onto a CCD array. Aberrated and unaberrated emission patterns are observed for z- and xr-orientated molecules, respectively. Reprinted with pennission from Bartko and Dickson [148]. Copyright 1999 American Chemical Society.

Figure C2.1.3. Schematic dependence of tire molecular weight of a polymer as a function of tire degree of monomer conversion for different polymerization reactions.

Figure C2.1.13. (a) Schematic representation of an entangled polymer melt, (b) Restriction of tire lateral motion of a particular chain by tire otlier chains. The entanglement points tliat restrict tire motion of a chain define a temporary tube along which tire chain reptates.

Figure C2.1.18. Schematic representation of tire time dependence of tire concentration profile of a low-molecular-weight compound sorbed into a polymer for case I and case II diffusion. In botli diagrams, tire concentration profiles are calculated using a constant time increment starting from zero. The solvent concentration at tire surface of tire polymer, x = 0, is constant.

Figure 4.1 Schematic illustration of possible changes in the specific volume of a polymer with temperature. See text for a description of the various lettered phenomena.

Several other chemical reactions are also widely used for the synthesis of these polymers. This list enumerates some of the possibilities and Table 5.3 illustrates these reactions by schematic chemical equations ... 

Table 5.6 Schematic Illustration Showing the Formation of a Linear Polymer by the Reaction of One of the f- 1 Reactive Groups at the End of a Portion of Polymer...

Lastly, we consider a class of compounds called ladder polymers, which are made up of a double-stranded backbone that is linked at regular intervals into rings so that the schematic structure is... 

Figure 8.2 Schematic illustrations of AGm versus X2 showing how jUj -may be determined by the tangent drawn at any point, (a) The polymer-solvent system forms a single solution at all compositions, (b) Compositions between the two minima separate into equilibrium phases P and Q.

Figure 8.11 The coil domains of two polymer molecules. The schematic shows by shading how the region of overlap increases as the distance between centers decreases.

To use GPC for molecular weight determination, we must measure the volume of solvent that passes through the column before a polymer of particular molecular weight is eluted. This quantity is called the retention volume Vj. Figure 9.14 shows schematically the relationship between M and Vj it is an... 

Figure 9.15 Schematic illustration of size exclusion in a cylindrical pore (a) for spherical particles of radius R and (b) for a flexible chain, showing allowed (solid) and forbidden (broken) conformations of polymer.

In addition, the intercept obtained by extrapolating this asymptote back to sin (0/2) = 0 equals (2M )". Note that both Mand are number averages when this asymptotic limit is used. This is illustrated schematically in Fig. 10.15 and indicates that even more information pertaining to polymer characterization can be extracted from an analysis of the curvature in Zimm plots. 

Fig. 25. Schematic representation of imprinting (a) cross-linking polymerization ia the presence of a template (T) to obtain cavities of specific shape and a defined spatial arrangement of functional groups (binding sites. A—C) (b) cross-linked polymer prepared from the template monomer and ethylene...

The solution process consists of four steps preparation of cellulose for acetylation, acetylation, hydrolysis, and recovery of cellulose acetate polymer and solvents. A schematic of the total acetate process is shown in Figure 9. 

Fig. 6. Schematic of dry-jet wet spinning employing tube-in-orifice spinneret A, bore injection medium (liquid, gas, or suspended soHds) B, pump C, spinneret D, polymer spinning solution E, micrometer ( -lm) "dope" filter F, coagulation or cooling bath G, quench bath and H, collection spool.

Fig. 17. Schematic stmcture of an LC side-chain polymer with embedded dyes (134).

Eig. 1. Schematic bioactive polyphosphazenes. (a) General stmcture, where X = hydrophilic /hydrophobic group that hydrolyzes with concurrent polymer breakdown, Y = difunctional group for attaching bioactive agent to polymer, and T = bioactive agent, (b) Actual example where X = —OC H, Y = and... 

Functionalized conducting monomers can be deposited on electrode surfaces aiming for covalent attachment or entrapment of sensor components. Electrically conductive polymers (qv), eg, polypyrrole, polyaniline [25233-30-17, and polythiophene/23 2JJ-J4-j5y, can be formed at the anode by electrochemical polymerization. For integration of bioselective compounds or redox polymers into conductive polymers, functionalization of conductive polymer films, whether before or after polymerization, is essential. In Figure 7, a schematic representation of an amperomethc biosensor where the enzyme is covalendy bound to a functionalized conductive polymer, eg, P-amino (polypyrrole) or poly[A/-(4-aminophenyl)-2,2 -dithienyl]pyrrole, is shown. Entrapment of ferrocene-modified GOD within polypyrrole is shown in Figure 7. 

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