Abstract: A process for preparing halogen-free, reactive polyisobutene having a terminal double bond content of more than 50 mol % and an average molecular weight Mn of 280-10000 dalton by the cationic polymerization in the liquid phase of isobutene or hydrocarbon mixtures comprising isobutene comprises polymerizing at from −30° C. to +40° C. in the presence of a heterogeneous polymerisation catalyst comprising one or more oxides of the elements of transition groups V and VI of the Periodic Table of the Elements or in the presence of a heterogeneous polymerization catalyst comprising one or more oxidic compounds of one or more elements of transition groups V and VI of the Periodic Table of the Elements supported on a non-zeolitic oxidic support material which is not an oxygen-containing zirconium compound, the catalyst not containing a technically effective amount of halogen.

Abstract: A process for the preparation of salts of dicarboxylic acids and diamines of the formulaH.sub.2 N-(R.sup.1 -O).sub.n -R.sup.2 -NH.sub.2 Iwhere R.sup.1 and R.sup.2 may be identical or different and are each alkylene of 2 to 4 carbon atoms and n is an integer from 1 to 3, which contain hydrazine in the form of hydrazine hydrate.

Abstract: Salts of oxaalkylenediamines of the formula IH.sub.2 N--(R.sup.1 --O).sub.n --R.sup.2 --NH.sub.2 Iwhere R.sup.1 and R.sup.2 may be identical or different and are each alkylene of 2 to 4 carbon atoms and n is an integer from 1 to 3, and alkanedicarboxylic acids of 4 to 12 carbon atoms, terephthalic acid or isophthalic acid, which contain hydrazine, their preparation, and nylons prepared from them.

Abstract: A process for making a polyurethane which comprises reacting an organic polyisocyanate with a higher molecular weight organic polyhydroxyl compound in the presence of a catalyst having the following formula: ##STR1## wherein X is sulfur or NH and n is a whole number from 2 to 6. Also used is a catalyst which is a combination of the above-mentioned catalyst and an organic tin compound.

Abstract: 4-substituted benzaldehyde-dialkylacetals of the formula ##STR1## where R.sup.1 is one of the radicals CH.sub.2 .dbd.CH--CH.sub.2 --, ##STR2## R.sup.2 is alkyl and R.sup.3 and R.sup.4 are hydrogen or alkyl, and a process for the electrochemical preparation of these compounds.