Phasenumwandlungen in Polymeren

Abstract

Da die Geschwindigkeit des Zerfalls (C) mit der kinetischen Methin-Aciditat zusammenhangt, kann die Halbwertszeit t ,,z als Ma8 fur diese dienen (Tabelle 2)., H e

Some thermodynamic quantities of n-alkanes as a function of chain length

“…[ RT,~ 1-___77o] 1 -n(AHO + 6t-F) In 1 [25] This equation is plotted in figure 8 together with the experimental data points available. The uppermost of the curves (eq.…”

Kink Block Structures in Clay Organic Complexes

“…The transition of a block of all-trans chains into gauche blocks is connected with a large decrease of the spacings in directions normal to the layers and seems to be unlikely in structures with low chain mobilities. It has been postulated for melts of polymers by Pechhold (Pechhold and Blasenbrey, 1970;Pechhold, et al, 1972). In our system the decrease of the basal spacing by transition into gauche blocks would exceed the observed step heights of 1.1 1.3 ~ very much and should increase with the chain length from about 5 A for decylammonium-decanol-beidellite to about 12 for octadecylammonium-octadecanol -beidellite.…”

“…Kink and gauche block arrangements have been proposed for the structure in melts of polyethylene and long chain paraffins (Pechhold and Blasenbrey, 1967;Blasenbrey and Pechhold, 1970). Using statistical thermodynamics and experimental data about melting enthalpies, specific volume changes, pressure dependency of the melting points, expansion coefficients and compressibilities, Pechhold assumed melting of these long chain alkyl compounds to be connected with a sudden increase in kink concentration from a lower limit of about 0-02 kinks/-CH2-to a value of about 0.25 kinks/-CH2-.…”