Imperial Chemical Industries

About: Imperial Chemical Industries is a based out in . It is known for research contribution in the topics: Alkyl & Catalysis. The organization has 8189 authors who have published 7809 publications receiving 190252 citations. The organization is also known as: Imperial Chemical Industries Ltd.

Polymer constitution and fiber properties

Abstract: The chemical structure of a large number of linear condensation polymers is correlated with their ability to assume a polycrystalline form possessing the right degree of thermal stability, and with the possession of fiber-forming properties. Certain structures lead to the absence of crystallinity and of fiber-forming properties, while, under certain conditions, a low degree of crystallinity or its complete absence leads to polymers possessing rubberlike properties, which may form highly elastic threads. Some properties of fibers such as solubility, sensitivity to mositure, and certain dyeing characteristics, can be correlated to some extent with chemical structure. These effects are considered on the basis of the introduction of various polar links and ring structures, according to regular patterns, into the polymethylene chain (polythee). The ehter (RO) and ester (CO·O) links lower the crystallite melting point to such an extent that some polymers containing them are completely noncrystalline at normal room temperatures. Urethan (O·CONH), amide (CO·NH) and urea (NH·CO·NH) links raise the crystallite melting point to an extent which increases in the order named. Most other polar links raise the melting point. The introduction into the aliphatic chain of ring structures, particularly aromatic rings directly attached to polar groups, raises the crystallite melting point, but in this case symmetry exerts an over-ruling effect. A low degree of symmetry may lower the melting point and even eliminate crystallinity entirely to the detriment of fiber-forming properties. Inert side chains lower the melting point considerably, and in some cases render the polymer completely noncrystalline at normal room temperatures.

Porous fluoropolymeric fibrous sheet and method of manufacture

Abstract: A method of preparing a porous sheet product which comprises the step of introducing a spinning liquid comprising an organic fibre forming polymeric material into an electric field whereby fibres are drawn from the liquid to an electrode and collecting the fibres so produced upon the electrode. PTFE and other fluorinated polymer mats produced by the electrostatic process are useful as electrolytic cell diaphragms, battery separators etc.

Thin Layer Chromatography of the Gibberellins

Abstract: PAPER chromatography of the gibberellins has been investigated by many investigators but no comprehensive study of all the known gibberellins has been reported. MacMillan, Seaton and Suter1 described four solvent systems which separate gibberellins A5, A6, A8 and A9 but not the pairs gibberellin A1 and gibberellic acid (A3) or gibberellins A4 and A7. The solvent systems used by Takahashi et al.2 and Phinney et al.3 do not separate gibberellins A1, A2 and A3. Gibberellins A1 and A3 can be separated on paper which is developed by overflow elution with benzene/acetic acid/water (4 : 1 : 2); this method is lengthy when conducted under gravity as described by Bird and Pugh4 and resolution is poor when development is hastened by centrifugal force5.