Macromolecules total length

Macromolecules total length L per polymer volume unit is estimated as follows [56] ... 

In the considered case the statistical segment—macromolecular stiffness section with mutually dependent orientation of position in space, is accepted as such particle [49], The statistical segment length is determined according to the Eq. (71). The total length of macromolecules L per polymer volume imit can be determined as follows [107] ... 

In a living cell, chains of biopolymers (DNA, RNA, proteins, polysaccharides) are built by special systems in an enzyme-mediated process called biosynthesis. This is a very robust process. Suffices it to say that if we fully stretch all DNA macromolecules synthesized in the human body during the life period the total length tm-ns out to be of astronomical scale two light-years And all the macromolecules forming this way are practically identical. 

Eor amorphons glassy polymers the equivalent of the degree of crystallinity, K, is the relative fraction

polymer volume unit under their dense packing [20] ... 

For intermediate drift rates (4 < BN < 8), when chain conformations are already distorted, deviates from linear behavior and goes through a maximum at some critical value Bf. of the field, confirming earlier findings by Pandey et al. [103,104]. This critical bias B at which the velocity starts to decrease depends rather weakly on the density Cobs, turns out to be reciprocal to chain length A, implying that only when the total force, /c = B,N 9, acting upon the whole driven molecule, exceeds a certain threshold, which does not depend on the size of the macromolecule, the chains start to get stuck in the medium. 

In transfer reactions the growth of a chain is ended, for example, by transfer of a hydrogen atom from the molecule ZH, but at the same time a new polymer chain is started by the radical Z that is formed simultaneously. Thus, several macromolecules result from one primary radical therefore, the kinetic chain length, i.e., the total number of monomer molecules induced to be polymerized by one primary radical, is much larger than the degree of polymerization of the macromolecules formed. A general scheme is as follows ... 

Let us now consider the behaviour of cyclic macromolecules at critical conditions. The macrocycle at critical conditions be transferred from the liquid phase into the pore in the following way (a) transform a cycle of length N into a linear molecule (AF = —3/2 In N) (b) transfer the linear molecule into the pore since this occurs at critical conditions, AF = 0 (c) form again a cycle in a slit-like (two-dimensional) pore (AF = In N). In going from (a) to (c), it is seen that the total free energy change for the transfer of the macrocycle into the pore at critical conditions is not equal to zero but depends on the size of the ring... 

Silberberg47) used a quasi-crystalline lattice model for the adsorption of flexible macromolecules. If it is assumed that an adsorbed polymer chain with P segments consists of ma trains of length i and mBi loops of length i, the total number of configurations of the chains is given by... 

The following substances for limiting polymer chain length in the manufacture of PC can be used phenol (< 2%), tertiary butylphenol (< 3%) or 4-(l,l,3,3-tetra-methyl-butyl)-phenol (< 5%). These substances are incorporated into the polymer macromolecule. PC can be mixed with copolymers of styrene, butadiene and acrylonitrile where the PC forms the bulk of the total mixture. 

Let us assume that the solution of semiflexible macromolecules occupies the volume V. Let i be the polymer volume fraction in the solution. Then, the average concentration of segments is c = 4 fibrpd3, the total number of segments N = Vc, and, finally, the average concentration of macromolecules is c//L, where L denotes the contour length of one macromolecule. 

Attempts to resolve this contradiction have been undertaken [68]. Maritan and Stella [69] calculated the fractal dimensions for 50 proteins using two methods. In one method, fractal dimension is a scaling index for the contour length of a macromolecule with respect to the distance between its ends (it is equal to 1.19-1.82), while in the other method, the fractal dimension is a scaling index for the total mass with respect to the length, which is equal to 1.62-2.24. The calculations were performed using X-ray diffraction crystallographic parameters of proteins. 

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