Hermann Staudinger, the founder of polymer chemistry, would have been 100 years old this year. One of the key materials with which he elucidated the structure of high polymers was polystyrene.-Polystyrene, one of the most important thermoplastics, has now been manufactured industrially for some 50 years. Not only has it simplified our daily lives in a variety of ways, it has also been a model substance for the development and expansion of polymer chemistry and polymer physics, and it was the pioneering material for handling polymer solutions and melts. This article surveys the development and present state of knowledge of the polymerization of styrene and of the relationships between structure and properties.
Hermann Staudinger, der Begründer der Polymerchemie, wäre 1981 hundert Jahre alt geworden. Eine der Schlüsselsubstanzen, an denen er den Aufbau der Hochpolymere aufklärte, war Polystyrol. – Polystyrol, einer der bedeutendsten thermoplastischen Kunststoffe, wird seit fünfzig Jahren industriell erzeugt. Es hat nicht nur unser tägliches Leben erleichtert, es war auch Modellsubstanz für den Auf‐ und Ausbau der Polymerchemie und ‐physik, es war Pioniermaterial für den verfahrenstechnischen Umgang mit Polymerlösungen und ‐schmelzen. Dieser Beitrag gibt eine Übersicht über die Entwicklung und den gegenwärtigen Stand der Kenntnisse über die Polymerisation des Styrols und über die Zusammenhänge zwischen Struktur und Eigenschaften.
The phase diagram of a binary polymer blend can be derived from the glass temperatures Tg of the demixed phases under the following conditions:1. The Tg's of the pure components are sufficiently different from one another. 2. The Tg's of the one-phase homogeneous mixtures can be determined and vary monotonically with composition.3. The equilibrium state of the mixture is attained after sufficient long annealing at temperature T.4. The equilibrium state at the temperature T can be frozen by quenching. These conditions are examined for mixtures of polystyrene (PS) and tetra methyl-bisphenol A-polycarbonate (TMPC). The phase separation kinetics is investigated with respect to size and composition of the co-existing phases. The co-existance curves (binodal with lower critical point) are determined for mixtures with various molar masses of the PS component. The problems concerning the cloud point curves are shortly discussed.Between Ts and the binodal the one-phase mixtures exist in a hindered thermodynamic state, because the crystallization of the TMPC component is a very slow process which requires very long annealing. With increasing amounts of PS in the mixture the crystallization half time of TMPC is lowered.
Eingegangen a m 12. Juni 1974 3,4-Diphenyl-1,2-cyclobutendion 1) (1) zeigt mit Grignard-Reagenzien ein unterschiedliches Reaktionsverhalten : Ried und Lanfzsch erhielten aus 1 und Arylmagnesiumbromiden cis-
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