The two-phase structure of segmented block copoly(ether ester)

Abstract

Abstract:The annealing induced morphological changes in isotropic block copoly(ether ester)s are investigated by small angle X-ray scattering methods. The observed results are consistent with a lamellar model which is comprised of a crystalline core of thickness 35 to 45 ~-, a diffuse boundary zone of width 9 ]l, and an amorphous layer which is varying strongly in thickness. The enhanced crystallinity of the samples annealed at higher temperatures is mainly due the lateral growth of the lamellae ; the long period increases by not more than 20%. The scattering power of the samples is explained by means of an equivalent two-phase model in which the crystalline phase has the same structure as the ceform of poly(butylene terephthalate), whereas the amorphous phase is a mixture of the uncrystallized ester segments and the ether segments. The crystallinity determined from the scattering power is very much higher than that determined from thermoanalytical investigations.

Microphase separation and rheology of a semicrystalline poly(ether-ester) multiblock copolymer

“…It is generally accepted that the crystalline hard domains of these multiblock copolymers are relatively pure in polyester segments, and that the soft domains are formed by a mixture of the polyester and polyether segments. A number of different morphologies have been found, including structures, 9,10,12,13 lamellae, 14,15 dendrites, 12,13 and even shish-kebabs 12 if the melt is sheared during crystallization. Although the multiblock characstorage modulus upon heating or a sharp rise ter of these polymers is the basis for their thermoupon cooling.…”

Solid state extrusion of thermoplastic elastomers 4

“…In the case of a pure two phase system, the mean square electron-density fluctuation, (/72), can be applied for the quantitative characterization of the degree of phase separation, as we pointed out previously [6]. The interpretation of the (//2) values for the oriented system is similar to that of the isotropic case and no additional restrictions are required.…”

“…It is easy to understand that 0a is a function of the composition of amorphous phase, which in turn is directly related to the glass transition temperature of the system. The values of r as calculated according to equation (6) are listed in table 2. That is because (//2) here depends both on Qa and ~.…”

“…The parameter (/72) was evaluated for some extruded samples using slit-smeared equatorial scattering intensity data, under the assumption of axial symmetry for the system. [6], which were employed for the extrapolation in the case of isotropic samples, are not suitable for this purpose. 9 Before performing the integration, the liquid scattering component was separated.…”

“…lit [11] N742 The two-phase structure of block copoly(ether ester) has been the subject of several investigations [5,6]. Geburtstag gewidmet.…”