Synthesis And Characterization Of Hexa[p-(carbonyl Glycino Methyl Ester) Phenoxy]Cyclotriphosphazene

As novel polymers with a backbone of alternating phosphorus and nitrogen atoms, polyphosphazenes have gained some properties through transforming two substituted groups on the phosphorus atom.This kind of materials presents both stability and activity.On the one hand,it exhibits useful properties such as water/oil repellence,radiation stability,high temperature endurance and nonflammability because of the inorganic P-N backbone.On the other hand,the chlorine atoms can be replaced easily by the organic groups to provide useful polymers.It can be used as flame retardant materials,special elastomer.Nowadays, phosphazenes show further development on photoelectric polymers,liquid crystalline,catalyst, dye and membrane.Recently,researches on the application of these compounds into medicine controlled release and biomaterials are very reactive.In this work,Hexa[p-(carbonyl glycino methyl ester)phenoxy]cyclotriphosphazene and intermediates are synthesized and their thermal properties and hydrolytic degradation behaviours in simulated body fluid are characterized respectively.In this work,hexa[p-(aldehyde)phenoxy]cyclotriphosphazene(HAPCP),hexa[p-(carboxyl) phenoxy]cyclotriphosphazene(HCPCP),hexa[p-(formyl chloride) phenoxy]cyclotriphosphazene(HFPCP),hexa[p-(carbonyl glycino methyl ester) phenoxyjcyclotriphosphazene(HGPCP)and the crosslinked polymer of polyethylene glycol ester and hexa[p-(carboxyl)phenoxyjcyclotriphosphazene were synthesized from respectively. These synthetic reactions took place under dry nitrogen protection.By using hexachlorocyclotriphosphazene(HCCP),4-hydroxybenzaldehyde,glycine methyl ester and polyethylene glycol ester as raw materials,sodium hydride and pyridine as catalysts,thionyl chloride as an acylation reagent,potassium permanganate as an oxidant,tetrahydrofuran as a solvent.The products were filtrated two times,washed by distilled water,crystallized and desiccated in the vacuum.Their structures were characterized and proved by ¹H NMR,¹³C NMR,³¹P NMR,FTIR and elemental analysis.Their thermal stability and crossing-linked structures were researched by thermogravimetric analysis(TGA),differential scanning calorimentry(DSC)and FTIR.The TGA data showed that the thermal stability of HAPCP,HCPCP and HGPCP were so high that their char residues were 75%,47%and 47%at 800℃respectively,which were probably due to cross-linked structures of benzoin(HAPCP)and anhydride(HCPCP and HGPCP)among molecules.While hydrolytic degradation behaviour of HGPCP was studied with UV-vis spectrophotometer and measuring the weight loss,the phosphorus content of residue. According to the results,the samples were mainly at the dissolved stage before 216 hours. After 504 hours,the sample hydrolytic process was still in the side chain break stage.It was easy to hydrolyze in hydrochloric acid(pH 1.0)than in phosphate buffer(pH 7.4)at 37°C.