Polymer drawn

The good hydrolytic stability of PCT-based polymers leads to applications for monofilament in paper machine belts. Monofilament is extruded from high-molecular-weight polymer, drawn and crystallized, and then woven into a screen. Such belts are found in the drying sections of paper machines, where there is a combination of high moisture and high temperature. Because of their hydrolytic stability, PCT-based polymers provide much longer service life in this application than PET-based materials. 

T. Kamisawa and M. Kimura, Poly (lactic acid)-type polymer drawn films with increased stiffness at high temperatures and good transparency, comprising poly (lactic acid) compositions containing (meth) acrylate polymers, Japanese Patent 2005036054 A2, assigned to Toray Industries, Inc., Japan, February 10, 2005. 

Figure 4.2. Repeat units of four polymers, drawn such as to facilitate immediate identification, by simple inspection, of those bond rotations which change the coordinates of some of the atoms, and therefore contribute to the count of the number of rotational degrees of freedom.

The ferromagnetic models proposed by Sarma4 and Hilhorst5 correspond to self-avoiding polymers drawn on a lattice. 

Fig. 112. A semi-infinite lattice (here n = 6) and a polymer drawn on this lattice from column 1 to column 9. The possible configurations of such polymers define a random system.

Let us now examine how the method applies when the critical system consists of a polymer drawn on the lattice (see Fig. 12.2). Of course, we must define n(x) for this system and we must show how this function can be calculated. 

Figure 5.7 Schematic representation of a portion of trifunctionally branched network polymer. (Drawn following Flory, 1941, 1946.)...

The values of A[ 7]ab and Aq for several pairs of vinyl polymers drawn from polystyrene, poly( methyl methacrylate), poly(vinyl chloride) and poly(vinyl acetate) are given in Table 4.35. It is seen that when the dipole moment of polymer A is very close to the dipole moment of polymer B, the incompatibility of the mixture, polymer A—polymer B, is very low. In the contrary, a mixture of polymer A and polymer B presents a high incompatibility when the dipole moment of polymer A is too different from that of polymer B. 

The behaviour of polymers drawn to low and intermediate draw ratios is similar in many ways to that of isotropic polymers, especially under... 

Polymer Drawn ratio Tensile strength (MPa) Elongation at break (% Young s modulus (GPa)... 

Figure 3.6 Plot of Eq. (3.48) for various values of the interaction parameter, x> as indicated in the diagram. A value of 1000 has been assumed for tr, the number of segments in the polymer. (Drawn following the method of Flory, 1942.)...

Schematic of microsyneresis uniform network of polymers in solvent (A) and phase-separated network with polymers drawn together (B).

A further interesting application of WAXD concerns the orientation of macromolecules in natural fibers, and in fibers of synthetic polymers drawn under the influence of an outer mechanical force. Fibers produce patterns that resemble those of single crystals of inorganic salts. Figure 6.11a and b illustrate, schematically, WAXD by a specimen with axial orientation, where the fiber axis is normal to the incident X-ray beam. Spot locations at the detector screen can be denoted by a radial distance from the primary beam, and by an azimuth /3 with respect to the meridian. 

Fig. 5.50 Schematic stress-strain curves of different types of polymers, drawn approximately to scale.

Figures VII.3 and VII.4 show the experimental values of the Young s modulus and the tensile strength, respectively, for thick films of undoped trans-polyacetylene as a function of draw ratio (all samples were derived from the same polymerization batch). Although there is some scatter in the data, the modulus and tenacity increase approximately linearly with the draw ratio, as is commonly observed for most polymers drawn to moderate draw ratios. The modulus and tensile strength of trans-polyacetylene films stretched up to 15 times are 50 GPa and 0.9 GPa, respectively. These values are essentially equivalent to those observed for ultra-high molecular weight polyethylene [83] drawn to the same draw ratio. Recently, Akagi et al.[78] reported remarkable mechanical properties for drawn polyacetylene films prepared by non-solvent polymerization (100 GPa and 0.9 GPa for the modulus and tensile strength, respectively). The origin of difference in the modulus (in the two studies) is unknown.

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