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六氯环三聚磷腈经二次重结晶一次减压升华纯化后,通过真空热开环聚合和亲核取代反应,用不同摩尔比的2-(2-氯乙氧基)乙醇钠和三氟乙醇纳(1∶3;1∶5;1∶6.5)作为亲核取代试剂混取代聚二氯磷腈,再经多次非溶剂沉淀纯化得到目标聚合物聚[(2-(2-氯乙氧基)乙氧基)x(三氟乙氧基)2-x]磷腈.利用31P-NMR监测,以确保得到纯化的聚合物.采用1H-NMR、FT-IR、GPC、DSC、XRD等测试手段对所得到的聚合物进行了结构表征和性能测试,并利用自制的压力法透气性能测定仪测定了这些聚合物的气体渗透系数.结果表明,三氟乙氧基和2-(2-氯乙氧基)乙氧基两种基团已接枝在聚磷腈侧链上,分别得到x值为0.19,0.18和0.08的3种聚[(2-(2-氯乙氧基)乙氧基)x(三氟乙氧基)2-x]磷腈,其玻璃化温度分别为-6.37℃,-12.85℃和-25.68℃,重均分子量为5.4×105,6.8×105和1.5×105,在同样的反应条件下,三氟乙氧基较2-(2-氯乙氧基)乙氧基有更强的竞争取代率.这种混取代聚磷腈较单一取代基的聚三氟乙氧基磷腈结晶度小,在本实验中两种取代基比例适中的聚[(2-(2-氯乙氧基)乙氧基)0.18(三氟乙氧基)1.82]磷腈的结晶度降至10.1%,这种聚合物显示出较高的气体渗透系数,CO2和He的气体渗透系数达到88.9和60.6 barrer,CO2/CH4和He/CH4的选择系数达到24.1和16.4,在天然气行业显露出良好的应用潜力.此外这类聚合物表现出特殊的H2/N2选择性,选择系数在0.2左右,N2的渗透系数为8.5 barrer,因而在合成氨行业显示出特殊的应用潜力.
Hexachlorocyclotriphosphazene after secondary recrystallization by a vacuum distillation sublimation purified by vacuum thermal ring-opening polymerization and nucleophilic substitution reaction with different molar ratio of sodium 2- (2-chloroethoxy) ethanol and trifluoro Ethanol (1: 3; 1: 5; 1: 6.5) as a nucleophilic substitution reagent, and then purified by multiple non-solvent precipitation to obtain the target polymer poly [2- Oxy) ethoxy) x (trifluoroethoxy) 2-x] phosphazene using 31 P-NMR to ensure that the purified polymer was obtained.H NMR, FT-IR, GPC, DSC, XRD The structure and properties of the obtained polymers were tested and the gas permeability coefficients of these polymers were measured by a self-made pressure-type gas permeability tester.The results showed that trifluoroethoxy and 2- (2 - chloroethoxy) ethoxy groups have been grafted onto the side chain of polyphosphazene to give three poly [(2- (2-chloroethoxy) ethoxy] x groups of 0.19, 0.18 and 0.08, Ethoxy) x (trifluoroethoxy) 2-x] phosphazenes having glass transition temperatures of -6.37 ° C, -12.85 ° C and -25.68 ° C respectively, weight average molecular weights of 5.4x10 5, 6.8x10 5 and 1.5 × 105, under the same reaction conditions, trifluoroethoxy than 2- (2-chloroethoxy Based ethoxy group has a stronger competitive substitution rate.The poly-substituted polyphosphazene has a smaller degree of crystallinity than the single-substituted polytrifluoroethoxyphosphazene, and in this experiment, the proportion of two kinds of substituents is moderate [ (2- (2-chloroethoxy) ethoxy) 0.18 (trifluoroethoxy) 1.82] phosphazenes is reduced to 10.1%. This polymer shows a higher gas permeation coefficient, CO2 and He gas permeability coefficient of 88.9 and 60.6 barrer, CO2 / CH4 and He / CH4 selectivity coefficient of 24.1 and 16.4, the natural gas industry has revealed good potential applications.In addition, this type of polymer showed a special H2 / N2 selectivity With a selection factor of about 0.2 and a permeability coefficient of N2 of 8.5 barrer, thus showing a special potential for use in the ammonia industry.