王艷麗 吳玲娜 金萬慧 胡國樑



摘?要:為提高芳綸濾料的耐高溫性并降低濾料的生產成本,以芳綸1313纖維為主要原料,通過混入不同質量分數的PAN預氧化纖維,制備了芳綸1313/PANOF復合針刺氈,并對其進行PTFE涂層整理。通過對所得復合針刺氈結構、力學性能、過濾性能以及耐高溫性能等進行表征和分析,結果表明:添加PAN預氧化纖維,提高了芳綸1313/PANOF復合濾料的纏結性能,減小了濾料的孔徑尺寸,濾料透氣量降低,過濾阻力增大;對于粒徑0.3 μm的微粒,PANOF質量分數低于35%時,濾料過濾效率隨PANOF含量的增加而明顯提高;隨著PANOF含量的增加,濾料橫向斷裂強度逐漸降低,橫向和縱向斷裂伸長率均逐漸增大;5組試樣均具有優良的耐高溫性,200 ℃高溫下,濾料的纖維結構沒有發生明顯變化,該濾料適用于200 ℃的高溫條件。
關鍵詞:芳綸1313;PAN預氧化纖維;過濾;耐高溫
中圖分類號:TS174
文獻標志碼:A
文章編號:1009-265X(2019)06-0026-05
Abstract:In order to improve the resistance to high temperature of aramid filter material and reduce its production cost, aramid 1313/PANOF composite needled felt was prepared by mixing pre-oxidation PAN fiber of different mass fractions into aramid 1313 fiber, and was coating finished with PTFE. The structure, mechanical performance, filtration performance and high temperature resistant performance of the composite needled felt were characterized and analyzed. The result show that the addition of pre-oxidation PAN fiber can improve the entanglement of aramid 1313/PANOF composite filter material, and decrease the pore size, so that the air permeability of filter material decreases, and the filtration resistance increases. For particles with diameters at 0.3μm, the filtration efficiency of the filter material is significantly increased with the increase of content of pre-oxidation PAN fiber in the case that the mass fraction of pre-oxidation PAN fiber is lower than 35%. The transverse breaking strength of filter decreases gradually, and the breaking elongation of transverse and longitudinal increases gradually with the increase of pre-oxidation PAN fiber. All samples of the five groups have good high temperature resistance. The fiber structure of the filter material has no obvious change at 200 ℃, so the filter material is suitable for the high temperature of 200 ℃.
Key words:aramid 1313 fiber; pre-oxidized PAN fiber; filtration; high temperature resistance
芳綸1313纖維(MPIA),全稱“間苯二甲酰間苯二胺”,是由間苯二胺和間苯二甲酰氯縮聚后經溶液紡絲而成,具有低剛度、高伸長、耐高溫、耐酸堿等優良特性,是制備耐高溫濾料的較理想材料[1]。由于間位芳綸纖維大分子結構中苯環與酰胺鍵之間存在空間位阻,在強堿或強酸的高溫環境中酰胺鍵會水解斷裂[2-3],這使得芳綸1313在電廠煙氣除塵領域的應用受到一定限制。
PAN預氧化纖維(PANOF)極限氧指數大于40%,熱穩定性優良,在火焰中燃燒不軟化收縮、無熔滴,具有優異的耐酸堿腐蝕性[4-6]。PAN預氧化纖維作為碳纖維的前驅體,價格低廉且性能優異,添加PAN預氧化纖維可以降低芳綸濾料的生產成本,彌補芳綸纖維高溫強酸堿環境下水解這一缺點,從而提高芳綸濾料在高溫煙氣過濾領域的綜合應用價值。本文以芳綸1313纖維為主要材料,通過與不同質量比的PAN預氧化纖維混合,制備過濾基材,將基材進行軋光和PTFE涂層整理得到芳綸1313/PANOF復合濾料。通過測試濾料的表觀形貌、拉伸性能、過濾性能和耐高溫性能來分析PAN預氧化纖維質量分數對芳綸1313/PANOF針刺濾料性能的影響。
1?實?驗