SynopsisDielectric relaxation spectra of a series of polyhydroxyether copolymers have been obtained. It has been shown that the systems exhibit very similar relaxation spectra with the (~(2'~) process a function of molecular weight. All systems exhibit two secondary relaxations: p (ca. 240 K) and y (ca. 180 K). These have been assigned as hydroxyl motion and main-chain motion, respectively.The peak positions are not functions of composition in the ranges studied. The effect of sorbed water on the relaxation spectra is discussed.

Alternating copolymers containing 4,4‐isopropylidene‐bisphenol (BPA) and comonomers with various degrees of polarity have been evaluated to find comonomer structures which provide low melt viscosity and good thermal stability. The materials were prepared by pyridine‐catalyzed nucleophilic displacement reactions similar to that for the preparation of BPA polycarbonate. The molecular weights of the polycarbonates depend on the concentration and nucleophilicity of the attacking diol and the concentration and stability of a colored pyridine‐chloroformate adduct formed during polymerization. The greatest thermal stability occurs for BPA–DMS and BPA–DEG. Thermomechanical flow measurements and Tg measurements were used to evaluate melt viscosity. The shapes and magnitudes of the Tg vs. Tf curves are sensitive to the copolymer chemical structure.

0. KRATKY mit herzlichen Gliickwiinschen zum 70. Geburtstag gewidmet (Eingegangen am 9. Dezember 1971)*) ZUSAMMENFASSUNG:Aus der Winkelabhangigkeit der Lichtstreuung von salzhaltigen DNA-Losungen kaun auf das Vorliegen von Fernordnungen in der Losung geschlossen werden. Diese Ordnung bildet sich in den ruhenden Losungen im Verlauf mehrerer Stunden bis Tage aus. Sie kann durch Riihren gestort werden und verschwindet in der Nahe der Schmelztemperatur der DNA.Aus den gemessenen Extremwerten der Streufunktion laBt sich formal ein BmwscherWert von 6000 A errechnen, aber auch Periodizitaten von 2000 A bzw. 3300 A sind moglich.Zwischen 1 .lOW bis 3 .lo-* g/ml laBt sich keine eindeutige Abhangigkeit von der Konzentration feststellen, wodurch man hier ein einfaches Parallelstranggitter ausschlieBen kann. Unmittelbar nach der Filtration durch Flachedlter der Porenweite 0,s pm zeigen die DNA-Molekiile stark gestorte, knauelartige Struktur. SUMMARY:The light-scattering-function of salty DNA-solutions indicate a wide-range order in the solution. This order is developing gradually in the solution at rest within a time of several hours to several days. Stirring causes distortion of the lattice. By heating near to the melting point it disappears. From the measured extremes in the scattering function, a BRAGGvalue of 6000 A can be calculated, but periodic distances of 2000 A and 3300 A respectively are also possible. I n the concentration range from 1 .lO-4 to 3 .lO-4 g/ml no clear dependence on the concentration can be detected, so a model of equidistant parallel rods can be excluded. Immediately after filtration through a planar filter having pores of 0.5 p n in diameter, the DNA-molecules appear to be strongly distorted and are rather coillike.