Synthesis And Structure Characterization Of Iron Modified Phenolic Resin And Preparation Of Nano-Carbon By Pyrolysis

In order to further improve the heat resistance of phenolic resin?PF?and its pyrolytic carbon properties,Fe³⁺were introduced into PF structure through coordination reaction,and iron modified PF was synthesized in this thesis.The modified PF can be used as solid pyrolysis carbon source for graphene or carbon nanotubes?CNTs?preparation.It's noteworthy for the controllability of the pyrolysis product of the phenolic resin.And it can be treated as a new preparation route for the industrial production of graphene and CNTs.Compared with ordinary PF,the heat resistance of iron-modified PF is obviously improved.The optimum synthesis process of iron-modified PF is:the ratio of the amounts of phenol,formaldehyde,NaOH,iminodiacetic acid,and FeCl₃ is 1:1.5:0.1:0.03:0.005,and the polycondensation reaction temperature and time is 90°C and 1.5 h,respectively.The structure of iron modified PF was characterized by FTIR and XPS,and its coordination number was determined by conductivity method.It was concluded that Fe³⁺forms a six-coordinate structure with phenolic resin and chelating agent,of which the 2 oxygen atoms come from phenolic hydroxyl groups and the 4 oxygen atoms come from the two carboxyl groups in the iminodiacetic acid structure.The pyrolytic carbon was characterized by XRD,SEM,Raman and TEM.The results show that graphene or CNTs are generated during pyrolysis.When the ratio of formaldehyde to phenol is 1.1,it is pyrolyzed to generate graphene,and when the ratio is 1.5,CNTs are generated.The resulting graphene has a lateral dimension of several tens of micrometers and a longitudinal layer of approximately five.The resulting carbon nanotubes have complete structure with the diameter of 80 to 100 nm and the length of several tens of micrometers,and the thickness of the tube wall is approximately 20 layers.