Abstract: A process for producing large-size formed articles consisting of a modified polyamide, by polymerization of a mixture containing, besides the omega-lactam corresponding to the polyamide, the following reagents:a) a polymerization catalyst selected from the sodium salt and the potassium salt of said omega-lactam;b) a polyoxyalkylene polyamine having a molecular weight ranging from 400 to 5,000 and an amine functionality ranging from 1.9 to 2.5;c) an activator consisting of a polyisocyanate having all the isocyanic groups blocked with a lactam;said reagents being fed, at a temperature of from 105.degree. to 125.degree. C., to a mold heated to 130.degree.-170.degree. C.

Abstract: A process for producing modified, impact-resistant polyamides showing an increased polymerization rate, which consists in polymerizing an .omega.-lactam in the presence of:(a) a mixture of an organic di-isocyanate and an organic mono-isocyanate, the isocyanate groups of both of which are blocked with an .omega.-lactam;(b) a poly-oxy-alkylene-amine having an aminic functionality lower than 3, and(c) an alkaline catalyst.

Abstract: A process for preparing trichloromelamine starting from chlorine and melamine, with intermediate formation of an aqueous suspension of hexachloromelamine, characterized in that hexachloromelamine is solubilized by addition of a water-immiscible solvent, the aqueous phase is separated and the hexachloromelamine solution is brought into contact, in the presence of an activator, with a number of melamine moles which is equal to or lower than the number of moles of the remaining hexachloromelamine.