Identificador: TDX:771
Autores: Ribera Llonc, Gemma
Resumen:
The organophosphorus compounds have demonstrated to be good flame retardants for materials with a high content in oxygen, since it is the case of the epoxy resins, beside less toxic gases and smoke generated that the halogen compounds. This way, it has been described as the introduction of phosphine oxides, so much in the chain of epoxy resin as in the curing agent, awards good properties of flame retardant since they act across a mechanism of lump, forming an insulating cap that constitutes a physical and thermal barrier to the combustion. The aims of this work are the synthesis and the crosslinking of new epoxy resins containing phosphorus, and the study of his thermal, mechanical and flame retardant properties.A route of obtaining epoxy resin containing phosphorus is the synthesis of phosphorus containing prepolymers derivatives of IHPO i DGEBA as well as of a new aliphatic diglycidyl, the HEDGE, nevertheless in this case as the HEDGE was reacting with the IHPO forming the prepolymer, at the same time his homopolymerization was taking place. In the same way as in case of the IHPO, the chain of the Fyrol 6 tried to lengthen by means of his reaction with DGEBA or with EPC, but the awaited reaction did not produce to itself what did that there was discarded this route of synthesis of phosphorus containing epoxy resins.An alternative route is the synthesis of phosphorus containing diglycidyl for what the IHPO made be reacted by EPC in basic way. This new diglycidyl experiences reactions of isomerization and decomposition to high temperatures, together with the reaction of thermal homopolymerization, which makes the use of a catalyst necessary in the reaction of treated, already is cationic or anionic.Another way of introducing phosphorus in the epoxy resin is treating diglycidyl compounds with curing agents that contain the group P=O. For this reason two phosphine oxide containing amino groups were synthesized, the BAMPO, a diamina that incorporates the group P=O joined directly two aromatic rings, and the 2DOPO-A, one diamina that incorporates two DOPO's molecules in his structure. Also the DAPPO was synthesized, a diamida where the nitrogen has a direct union with the atom of phosphorus, which was decided to include in the study of the reactions of treated by the synthesized diglycidyl, because was producing low degrees of crosslinking.Once obtained the phosphorus compounds was studied of the curing reaction of the DGEBA by five curing agents (HMDA, DAT, DDM, BAMPO and 2DOPO-A) and was compared with the results obtained of curing of the IHPO-Gly and the HEDGE with these five aminas. Of this study it is clear that the three diglycidyl present similar temperatures of reaction, without it could establish no relation with the chemical structure of the diglycidyl, to different of the obtained Tg, which meet affected so much for the structure of the diglycidyl as of the curing agent. Also IHPO-Gly's mixtures realized with HEDGE or DGEBA, in proportions that contain the 1, 3, 5 and 7 % of P to be able to see the influence of the quantity of present phosphorus in the final resins, which they react with DAT and with DDM. In the systems IHPO-Gly/HEDGE an increase of the Tg was observed by the presence of the unit P=O, whereas in the systems IHPO-Gly/DGEBA the variation of the Tg is associated with the presence of the aromatic structure.By means of the technology of the DMTA could be observed the Tg of the obtained materials, as well as an easing towards-50 provoked by the segments of the oxyranic rings opened, in all the cases. By means of the technology of the TGA it was possible to determine that the presence of phosphorus disables the oxidative degradation of the carbonated rest in air atmosphere, producing the formation of a intumescent residue that protects the material of the fire. Finally, by means of the application of the Test UL-94 of vertical burned, all the materials were classified like V-0.
Repositori URV