Preparation And Characterization Of Benzoxazine And Isonitrile Compounds

Benzoxazine is a type of six-membered heterocyclic compound synthesized by phenols,amines and formaldehyde under mild reaction conditions.In this paper,crude phenol was used instead of phenol to obtain crude phenol-based benzoxazine prepolymer,and its heat curing properties had been studied.As the isomer of nitrile compounds,isocyanide compounds have been widely used in organic chemical reaction.A series of isonitrile compounds had been synthesized by formamide method,and their properties had been studied.In the preliminary work,it was found that there might be some specific functional group reaction between benzoxazine and isonitrile.On the basis of successfully preparing a series of benzoxazine and isonitrile reaction substrates,the reaction between them was initially studied.The results are as follows:1.Benzoxazine compounds M1~P2 were successfully prepared by common phenols,amines and formaldehyde in laboratory with solvent method.The crude phenol-based benzoxazine resin prepolymer was successfully prepared by using crude phenol instead of phenol,polyether amine and paraformaldehyde as raw materials.The synthesized prepolymer was heat cured and the benzoxazine resin spline of different size was obtained according to the national standard.Its physical and chemical properties were also tested.The results showed that the cured resin had nearly 0 volume shrinkage,good anti-dissolution,low water absorption,bending and tensile strength reached 92.71 MPa and 25.79 MPa respectively.In addition,the crude phenol-based benzoxazine resin was loaded on absorbent cotton,and a new type of hydrophobic oil-absorbing material was successfully prepared.The material had good adsorption effect on several kinds of oil,and its repeated usewas more than 20 times.2.The isonitrile compounds M5~M9 were successfully prepared by N-substituted formamide dehydration method.Based on the study of the optical properties of the isonitrile compound M9 with aggregation induced emission effect,it was found that M9 displayed the specificresponse to the toxic metal ion Ag~+ in the THF/H2O(V/V=3:7)mixed system.The detection illustratedgood anti-interference and high sensitivity,and the detection limit was 1.97×10-7mol · L-1.By studying the fluorescence response mechanism,it was found that M9 and Ag~+were combined witheach other with 1:1 ratio,which caused aggregation of the M9 molecule,resulting in a fluorescence enhancement effect.3.The compounds M10~P6 were prepared by using the synthesized benzoxazine and isonitrile compounds as raw materials and chloroform as the reaction solvent.The compounds were characterized by FT-IR,1H NMR,and TOF-MSinvestigation.The possible interaction mechanism of benzoxazine and isonitrile was proposed.In addition,it was found that glacial acetic acid as a mild catalyst can catalyze the reaction of benzoxazine and isonitrile,and the possible interaction mechanism was also proposed.