Abstract: The invention relates to a novel pyrimidine derivative. This derivative is 4,6-di-2-(5-nitro-1,2,4-triazole)-5-nitropyrimidine of formula: ##STR1## in the form of the pure isomer or mixtures of isomers. It can be prepared by reacting a dihalogeno nitropyrimidine with 5-nitro-1,2,4-triazole.It can be used as a secondary explosive.

Abstract: The invention relates to a novel pyrimidine derivative, which is 4,6-di-(3-amino-5-nitro-1,2,4-triazole)-5-nitropyrimidine of formula: ##STR1## It can be prepared by reacting a dihalogeno nitropyrimidine with an alkali metal salt of 3-amino-5-nitro-1,2,4-triazole. It can be used as a secondary explosive.

Abstract: The invention relates to 5-nitro-2(3,5-diamino-2,4,6-trinitrophenyl)-1,2,4-triazole of formula: ##STR1## It is prepared by reacting a 1-halogeno-3,5-diamino-2,4,6-trinitrobenzene with 3-nitro-1,2,4-triazole or one of its alkali metal salts.This triazole derivative can be used as a secondary explosive. It has a lower shock sensitivity than octogen, while still being able to supply a high energy.

Abstract: The present invention relates to a process for the preparation of polyphenol derivatives, new derivatives obtained by this process and their use in the preparation of polymers and copolymers.This process consists of reacting a polyphenol with 1-allyloxy-2,3-epoxypropane of formula: ##STR1## in the presence of a catalyst constituted by a tertiary amine or an alkali hydroxide to obtain a polyphenol derivative having two reactive functions, i.e. allyl and hydroxyl at each end.Preferably, the phenols used are bisphenol A, bisphenol A derivatives, such as polysulphones or polycarbonates and phenol-formaldehyde resins.The derivatives obtained in this way having two reactive functions of different types at each end of their chain (hydroxyl and allyl) can participate in polymerization, copolymerization and/or crosslinking reactions.