Study On Synthesis, Relation Between Properties And Structure And Application Of Novel Bismaleimide Triazine Resins

With the development of science and technology, materials with high properties were desired for the need of aerospace structural composites, high-speed printed circuit boards, et al. Therefore, the advanced composite materials are manufactured for this aim, such as bismaleimide resins, dicyanate ester resins and bismaleimide triazine resins. Bismaleimide resins and dicyanate ester resins are thought as advanced composite materials instead of epoxy resin, but the brittleness and their poor processability of bismaleimide resins and poor hydrolytic decomposition resistance of dicyanate ester resin limit their application to advanced composite materials. For avoiding to thermal property loss during the modification for enhancing toughness, the molecule design method is used to introducing naphthalene and ether into structure to ameliorating potential flame retardancy, toughness and processability and no losing thermal properties in this paper. Introduction of naphthalene also decrease the dielectric constant and moisture absorption of resins.The novel dicyanate ester monomers and bismaleimide monomers including of naphthalene and ether linkage were synthesized in this paper. Cure kinetics and properties of different structures were analyzed for dicyanate ester resins, bismaleimide resins and their blends. Laminate composites of their resins were made, and tested the properties, such as bending rigidity, dielectric constants, moisture absorption, et al. The relation of properties with structures was discussed on the basis of the application of novel monomers.Firstly the novel monomers of dicyanate ester and bismaleimide were synthesized. The best conditions of synthesizing monomers were found. Their monomers were characterized by FTIR, NMR, polarizing microscope, et al.The cure kinetics of different dicyanate ester resins were analyzed by DSC, FTIR methods. The effects of structure on cure kinetics of dicyanate ester resins were obvious because of short distance between different structure of R and nitrile group. The activation energy of cure reaction was increased due to introduction of naphthalene in structure of dicyanate ester resin, but the order of cure reaction was not changed. The introduction of naphthalene also influenced on the rigidity of molecule chains, and make a gel decreased, but the addition of catalysts did charged a gei of dicyanate ester resins.The effects of catalysts on the cure kinetics of dicyanate ester resin were studiedIVby DSC, FTIR methods. The composite catalysts of acetylacetonate and nonylphenol have good catalysis for dicyanate ester systems. The catalytic action of Fe(AcAc)3 was best, but the its effect on thermal properties was also most severe. The catalytic action of Co(AcAc)2 was only inferior to that of Fe(AcAc)3, and the its effect on thermal properties was minimal. The dosage of nonlyphenol was not exceeded 2%, or else its effect on thermal properties was obvious.The cure kinetics of different bismaleimide resins were analyzed by DSC and FTIR methods. The activation energy of cure reaction for BMPN resin was close to one of cure reaction for BMPB resin, but the activation energy of cure reaction for BMPA resin was comparatively lower. The action of cure reaction didn't be influenced because of far distance between different structure of R and double bond of maleimide ring. The different structure of R influenced on the rigidity of molecule chains, thus effected on a gel and charged activation energy of cure reaction for bismaleimide resins.The cure kinetics of blends of BMPN and DNCY were analyzed by DSC, FTIR and SEM methods. The cure kinetics were different under different conditions of cure reaction. BMPN and DNCY happened co-curing under conditions of high cure temperature and no catalysts in blend systems of BMPN and DNCY. But small BMPN monomers were homopolymerized under this condition due of their difference of cure rate. Each of BMPN and DNCY happened homopolymerized to form IPN structure in blend system including of O.llmmol/mol of Fe(AcAc)3 and 2phr of...