Draw ratio value growth

From the Eq. (4.38) V increase follows and from the Eq. (1 9) - the increase at drawing ratio X growth. In its turn, the value X is connected with the strain e by a simple relationship (in the case of affine deformation) [80] ... 

The limiting draw ratio at fracture increase at extrusion draw ratio X growth is one from the most interesting features of the amorphous polymers extrudates [26,61]. Such effect was observed and in the case of DF-10 extrudates [2], Let us consider the value theoretical estimation... 

As oriented polymers studies showed [20], for them the value v at drawing ratio growth reached the magnitude -0.425 very fast and further remains practically constant. Therefore, calculation with the Eq. (13.14) using gives the value y = 7.03. Thus, the theoretical estimation of film samples fracture stress o can be fulfilled as follows [21] ... 

The total componors fracture probability p in mechanical tests is obviously equal to one. Further this value is divided at the conditionp =p +P2 follows. In Fig. 14.10, the dependence of fracture stress a on extrusion draw ratio X for componor UHMPE-Al is shown. As one can see, the growth is ceased and changes to drop(compare with the plot of Fig. 14.6). Such the dependence Oj( l) type is due to interfacial boundaries pol5mier-filler fracture at > 5 [44]. Hence, at < 5 the fracture of pol5mier matrix and interfacial boundary is equally probable (p =p = 0.5) and at A, > 5 the second fracture probability is higher (p >P2)- In addition it is assumed, that at A 5 is... 

The Eqs. (14.21) and (14.22) together with estimated by considered above method parameters A nd allow to calculate the dimensions and [55]. In Fig. 14.11 the dependences of Renyi characteristic dimensions and on extrusion draw ratio for componors UHMPE-Al and UHMPE-bauxite. As one can see, at the definite values X XJ the componors structure transition from multifiractal (canonical spectrum, grows at q increase [59]) to regular fractal D- = occurs and then at X>X - again to multifiractal (pseudospectrum, D decreases at q growth). 

For oriented polymers it is shown that the value of n depends also on the drawing ratio [18,27]. Reduction in n with growth in A, is a general tendency. A considerable number of factors influencing the value of n makes its description within the frameworks of structnral and molecular models difficult. Therefore the authors of papers [34-36] generalised the influence of the indicated factors on the value of n with the application of fractal analysis methods in the example of uniaxially stretched PCP. Molecular characteristics of PCP crosslinked networks are adduced in Table 4.2. 

One other mode of PCP crystallisation kinetics within the frameworks of the thermodynamic approach [39] was considered in paper [40]. It has been shown by the indicated approach that crystallisation kinetics is defined to a considerable extent by the drawing ratio X of polymers. At a certain value of X (XJ a crystalline phase morphology change from lamellar to fibrillar occurs that defines the transition to linear growth of the one-dimensional volume of crystallites. In paper [39] theoretical dependences of the parameter (1 -x/K ) on the crystallisation duration were obtained, corresponding to the equation ... 

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