Sdudy On Application And Catalytic Synthesis Of POB With Solid Superacid

SO₄^2-/ZrO₂ and SO₄^2-/Al₂O₃ zeolite solid superacid are prepared and applied tocatalytic synthesis of POB. Synthesis process conditions of catalyst and POB arediscussed. The results show that.Using SO₄^2-/ZrO₂ zeolite solid superacid as catalyst, the optimal conditionis:H₂SO₄ soaked concentrationl mol/L, calcinations temperature 550℃, soak time is6h, catalyst amount is 0.5g, esterification time is 2.5h, condense polymerization time is1.5h, condense polymerization temperature is 330℃～340℃. The yield of POB is 92%under this optimal condition.Using SO₄^2-/Al₂O₃ zeolite solid superacid as catalyst, the optimal conditionis:H₂SO₄ soaked concentration is 1mol/L, calcinations temperature is 600℃, soaktime is 6h, catalyst amount is 0.5g, esterification time is 2.5h, condense polymerizationtime is 1.5h, condense polymerization temperature is 330℃～340℃. The yield of POBis 88% under this optimal condition.XRD and SEM studies on the surface of SO₄^2-/ZrO₂ and SO₄^2-/Al₂O₃ zeolitesolid superacid catalyst show that: Zr and A1 is adsorbed at the surface of zeolite.SO₄^2-/ZrO₂ and SO₄^2-/Al₂O₃ also is adsorbed as crystal form. Zeolite solid superacidcatalysis mechanism is discussed. The results show that zeolite has a lot of holeystructures, big specific surface area; strong adsorption capacity. and has acidity.SO₄^2-/ZrO₂ and SO₄^2-/Al₂O₃ are adsorbed at the surface of zeolite makes the numberof active acid centers increased a lot. Catalysis is strengthened greatly as zeolitebecomes superacid. Zeolite solid superacid shows good catalysis performance at thestudy of synthesis of POB which has high yield. That zeolite solid superacid can beseparated from intermediate products after esterification reaction, won't influencecondense polymerization reaction. Moreover, it has long use life and uses repeatedly.So it is of great use value.Result of DSC Characterization of POB shows that: Melt temperature of POB is443℃. This shows high melt temperature and good heat stability of POB. IRCharacterization of POB also is studied.Tearing bend performance and hardness of PTFE composites are obviously improved when POB is applied in PTFE. Composites show best general performancewhen POB amount is 20wt%. As the content of POB increases, friction coefficient ofcomposites augments on linear relationships. Wearing volume of samples decreasefrom 115.7mm³(pure PTFE) to 1.74mm³ (containing 5wt% Ekonol). The performanceof wearing resistance is enhanced 66.5 times.