Eniricerche S.p.a.

Agip Petroli

Snam S.p.a.

Anic S.p.a.

Claudio Valentini

Raffaello Sisto

Arnaldo Roggero

Alberto Gandini

Alessandro Stopponi

Ugo Pedretti

Amalia Assogna

Francesco Bartoli

Giulio Alberti

Otello Farias

Raffaella Monga

Mario Fiorini

Francesco Di Gregorio

Claudio Demofonti

Umberto Constantino

A hollow fiber of amorphous, hydroxy-ethylated poly-(2,6-dimethyl-p-oxyphenylene) (PPO-OH) with a glass transition temperature (Tg) of from 180.degree. to 200.degree. C. is disclosed, which is formed by a high-density, microporous layer on a macroporous backing, and having an outer diameter comprised within the range of from 450 to 550 .mu.m and an inner diameter comprised within the range of from 250 to 400 .mu.m. The process for preparing the hollow fibre and the use of said fibre in the processes of separation of gas mixtures are disclosed as well.

Hollow fibres of modified poly-(2,6-dimethyl-p-oxy-phenylene)

An amorphous modified poly(2,6-dimethyl-p-oxyphenylene) (PPO) is described with a glass transition temperature (Tg) within the range of 170.degree.-220.degree. C., of which the macromolecules contain units having trialkylsilyl groups bonded to the nucleus and/or to the methyl: ##STR1## together with units having hydroxyethyl groups bonded to the nucleus and/or to the methyl: ##STR2## This modified PPO is prepared by metalating PPO with a metalating agent and reacting the formed metalated PPO with a trialkylsilyl halide and with ehtylene oxide in succession. The use of the thus modified PPO for the preparation of flat, including asymmetric, membranes useful in gas mixture separation processes is described.

Modified poly(2,6-dimethyl-p-oxyphenylene), a process for its

A process for preparing a modified, amorphous poly-(2,6-dimethyl-p-oxyphenylene) (PPO) comprises:

Process for preparing modified poly-(2,6-dimethyl-p-oxyphenylene)

A modified poly(2,6-dimethyl-p-oxyphenylene) with a glass transition temperature in the range of 180.degree.-220.degree. C. is described in which on the average between 10 and 60% of the macromolecules carry:

Alkylene oxide modified poly(2,6-dimethyl-p-oxyphenylene)

The invention relates to a zirconium phosphate in particles having sizes comprised within the range of from 1 to 100 .mu.m, a lamellar structure with interlayer distance, in the anhydrous state, comprised within the range of from 7.9 to 8.2 .ANG. and a surface area comprised within the range of from 9 to 20 m.sup.2 /g. The method consists in altering the lamellar structure of a zirconium phosphate with layer structure of alpha type by intercalating into it an organic substance containing a proton-acceptor group and water and by a treatment with ultrasounds, in regenerating the hydrogen form of said zirconium phosphate by an acid and in washing the same with diluted acids and/or water.

Zirconium phosphate and method for its preparation

L-carnitine is prepared by a synthesizing process starting from D-mannitol. The synthesis is started with the formation of a D-mannitol ketonide (more specifically D-mannitol acetonide from D-mannitol and acetone, whereafter the D-mannitol is split by oxidation to give glyceraldehyde acetonide, which is further reduced to glycerol acetonide. Then the free hydroxyl group is exchanged with a halogen atom (chlorine) with the formation of chlorodihydroxy propane, the primary alcoholic group of which is functionalized with the acid chloride of a sulfonic acid (tosylchloride). The reaction of the tosyl derivative with the salt of hydrogen cyanide leads to the formation of the corresponding nitrile which, when reacted with trimethylamine gives carnitinonitrile. The nitrile group is now hydrolyzed to give L-carnitine chloride. The formation of L-carnitine can then be obtained by exchanging the chloride ion with a hydroxyl ion.

Method for preparing L-carnitine

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Rome, Italy

Claudio Valentini