Average chain length characteristics

Using results of these kinds of studies, the characteristic structure of amylose can be differentiated from that of amylopectin. Amylose has a small number of branches and crystallizes and precipitates when complexed with 1 -butanol. The iodine affinity of amylose is much greater (i.a. 18.5 to 21.1) than that of amylopectin (i.a. 0.0 to 6.6),79,152-158,163,169-174 and the iodine affinity of amylose (3-limit dextrin is similar to that of the parent amylose. The average chain length of amylose (3-limit dextrins is much larger than that of the amylopectin (3-limit dextrin.160... 

The description of a network structure is based on such parameters as chemical crosslink density and functionality, average chain length between crosslinks and length distribution of these chains, concentration of elastically active chains and structural defects like unreacted ends and elastically inactive cycles. However, many properties of a network depend not only on the above-mentioned characteristics but also on the order of the chemical crosslink connection — the network topology. So, the complete description of a network structure should include all these parameters. It is difficult to measure many of these characteristics experimentally and we must have an appropriate theory which could describe all these structural parameters on the basis of a physical model of network formation. At present, there are only two types of theoretical approaches which can describe the growth of network structures up to late post-gel stages of cure. One is based on tree-like models as developed by Dusek7 I0-26,1 The other uses computer-simulation of network structure on a lattice this model was developed by Topolkaraev, Berlin, Oshmyan 9,3l) (a review of the theoretical models may be found in Ref.7) and in this volume by Dusek). Both approaches are statistical and correlate well with experiments 6,7 9 10 13,26,31). They differ mainly mathematically. However, each of them emphasizes some different details of a network structure. 

To clarify the unique characteristics of the MWD of emulsion polymers, one of the simplest and most common cases [264], where neither chain transfer (Cf=0) nor radical desorption ((5=0) occurs, is considered here. The magnitude of bimolecular termination ( ) is changed with a constant radical entry frequency (c=2xl0 ). Figure 10 shows the calculated number- and weight-average chain lengths and the polydispersity index (PDI= as a func-... 

Fig. 5 Ideal chain length characteristics for end-to-end self-assembled telechelic chains for different values of K. (a) Average dynamic chain length, X , plotted against the total concentration of telechelic chains, c. (b) Distribution of chain lengths at a fixed concentration (c = 0.002 mol L ) of telechelic chains determined by simultaneously solving a set of n = 200 equations for c ...

Many commercial polymers, including polystyrene, PMMA and LDPE, are synthesized via homogeneous FRP of a single monomer. Homopolymer properties are controlled by average chain length and chain-length distribution as well as, in some cases, structural characteristics such as branching level. 

Because of its superior solubility characteristics, a high 2-phenyl LAS (with an alkyl chain length average of 11.4) was the preferred type. The detergency performance of one LAS/AE type of formulation was discussed previously (see Figs. 12 and 13). Early commercial heavy-duty liquid (HDL) formulations were built with phosphate, but since 1979 almost all U.S. HDLs have been formulated without phosphate. 

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