Study On Phosphorus-containing Reactive Monomers And High-performance Polymers

Introducing phosphorus into polymers is an effective way to obtain polymer materials with excellent properties.Toxic compounds such as white phosphorus and phosphorus trichloride don’t have safe environmental conditions,while tetrakis（hydroxymethyl）phosphonium sulfate（THPS）,a secondary phosphorus chemical product,contains the reaction group hydroxymethyl.With high efficiency and fast sterilization,relatively low molecular weight and easy biodegradation,green,non-toxic and environmentally friendly characteristics,it is one of the preferred materials for the synthesis of phosphorous polymers.In this paper,several phosphorus-containing reactive monomers and two high-performance polymers were prepared from THPS,and the properties of the polymers were studied.The main contents include:（1）Synthesis of phosphorus-containing isocyanates by Catalytic thermal cracking.Tris（N-carbomethoxylaminomethyl）phosphine oxide and bis（N-carbomethoxyl-aminomethyl）benzyl phosphine oxide were synthesized from THPS,and their structures were characterized by IR,~1H-NMR,¹³C-NMR,³¹P-NMR.Thermogravimetric analysis（TG）was used to screen out the optimal catalysts from zinc powder,zinc oxide,gold wire,montmorillonite,and the mixture of zinc powder and zinc oxide.The results show that zinc oxide can reduce the catalytic thermal cracking temperature to the greatest extent,Therefore,two polyphosphorus-containing isocyanates were prepared by catalytic thermal cracking of Tris（N-carbomethoxylaminomethyl）phosphine oxide and bis（N-carbomethoxylaminomethyl）benzyl phosphine oxide using zinc oxide as catalyst.The structures of thermal cracking products were characterized by IR,TG-MS and VTIR.（2）Synthesis and properties of A2B3 phosphorus-containing hyperbranched polyamide.Tris（aminomethyl）phosphine oxide was synthesized with THPS,and its structure was characterized by IR,~1H-NMR,¹³C-NMR and ³¹P-NMR.A phosphorus-containing hyperbranched polyamide was prepared by polycondensation reaction with 4,4’-biphenyl dicarboxylic acid as A2 mononmer and tris（aminomethyl）phosphine oxide as B3 mononmer;The structure of the hyperbranched polyamide was characterized by IR,~1H-NMR,¹³C-NMR,³¹P-NMR,and the properties were studied by TG,DMA and MCC,etc.The results showed that the DB of the polymer is 0.69.The results of TG showed that the initial decomposition temperature T5（5%weight loss temperature）and T₁₀（10%weight loss temperature）were 225℃and 326℃,respectively,and the maximum decomposition temperature Tm（maximum weight loss rate temperature）was348°C,indicating that the phosphorus-containing hyperbranched polymer had excellent thermal stability.And the LOI value reaches 33.49%,which calculated from the char yeilds at 850°C,indicating that the material had excellent flame retardancy.DMA results show that the material has a glass transition temperature at 103℃and a high storage modulus of 60-80 GPa at 30-90℃,indicating that the material had good thermomechanical properties.The THR and PHRR were 12.4KJ/g and 286W/g,and the temperature was 342.8℃by the MCC,the limiting oxygen index calculated was38.3%from this data.（3）Modified preparation and properties of phosphorus-containing polyamide-66.Bis（aminomethyl）phenylphosphine oxide was synthesized from THPS,and its structure was characterized by IR,~1H-NMR,¹³C-NMR and ³¹P-NMR.The phosphorus polyamide-66 prepolymer was synthesized by adding 2.5%,4.5%,10%,15%（substance fraction）of bis（aminomethyl）phenylphosphine oxide to 1,6-hexanediamine,and reacting with dimethyl adipate respectively.Its structure was characterized by IR and NMR.The properties of the materials were investigated by TG,DMA,SEM,tensile test and XRD.The TG results showed that the T5 and T10 were around 300℃,and the Tm is around 400℃,indicating that phosphorus-containing polyamide-66 had good thermal stability;With the increase of P content,the char yields at 850℃increases,indicating that the introduction of a small amount of P can significantly improve the flame retardant performance of the material.DMA results show that the introduction of phosphorus does not reduce the mechanical properties of the polymer.The SEM analysis of the material combustion section shows that the introduction of a small amount of P makes the material easier to produce carbon deposits during the combustion process,and the flame retardant performance of the material increases.The tensile test results show that the introduction of a small amount of phosphorus has little effect on the toughness and tensile properties of the material.XRD results showed that the introduction of phosphorus did not change the crystal form of the polymer...