本文關(guān)鍵詞： PTFE中空纖維膜 潤滑劑 擠出工藝 拉伸工藝 燒結(jié)工藝　出處：《浙江理工大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：中空纖維膜由于其占地面積小、填裝密度大、利用率高、易放大、清洗簡便等特點,被廣泛應(yīng)用于超濾、微濾、反滲透、氣體分離器等傳統(tǒng)和新型的膜分離組件形式[1,2]。此外,由于聚四氟乙烯中空纖維膜力學(xué)強度高、耐酸堿、耐高低溫、表面摩擦系數(shù)低等特點,在特種過濾、氣體吸收、臭氧溶解過濾、膜蒸餾等領(lǐng)域應(yīng)用潛力大[3]。本文采用聚四氟乙烯分散樹脂為原料,加入�？松梨诋悩�(gòu)烷烴類Isopar系列潤滑劑,通過糊料擠出和拉伸成型的方法,制備PTFE中空纖維膜。采用擠出平均壓力、孔徑和泡點壓強、孔隙率、水通量、接觸角、SEM和DSC等測試來表征PTFE中空纖維膜的結(jié)構(gòu)與性能。實驗主要探討潤滑劑(種類和配比)、擠出工藝(壓縮比、長徑比和錐角)和拉伸燒結(jié)工藝對PTFE結(jié)構(gòu)和性能的影響,優(yōu)化各工藝參數(shù),為PTFE中空纖維膜的生產(chǎn)提供指導(dǎo)。具體研究內(nèi)容如下:(a)實驗改變潤滑劑參數(shù)(包括潤滑劑種類、配比),通過“混合→預(yù)成型→擠出→拉伸→燒結(jié)→自然冷卻”的工藝路線制備PTFE中空纖維膜。實驗通過探究潤滑劑的種類和配比對PTFE中空纖維膜的結(jié)構(gòu)和性能的影響,得到潤滑劑種類和配比的最佳組合,優(yōu)化潤滑劑。(b)通過改變擠出工藝模具的參數(shù),探究壓縮比RR、長徑比L/D、椎角α對擠出壓力、膜斷裂強力、平均孔徑、泡點壓強、孔隙率和水通量的影響規(guī)律,得到最佳的擠出參數(shù)。(c)通過調(diào)節(jié)拉伸工藝參數(shù)(拉伸倍數(shù)和拉伸溫度)和燒結(jié)工藝參數(shù)(燒結(jié)溫度和燒結(jié)時間),探究拉伸燒結(jié)工藝對PTFE中空纖維膜平均孔徑、泡點壓強、孔隙率和水通量的影響規(guī)律,得到最佳拉伸燒結(jié)工藝參數(shù),優(yōu)化拉伸燒結(jié)工藝。實驗結(jié)果表明:(1)潤滑劑種類為IsoparG、配比為20%所得到PTFE中空纖維膜平均孔徑小、泡點壓強和孔隙率高、水通量大斷裂強度和接觸角大且擠出過程中擠出壓力低。潤滑劑含量過高或過低時,對PTFE中空纖維膜的結(jié)構(gòu)和性能均有一定程度的不利影響。(2)當(dāng)壓縮比RR=185、長徑比L/D=20、椎角α=40°時,擠出過程中擠出壓力低、斷裂強力大、平均孔徑小、泡點壓強高,孔隙率大、水通量高,可作為優(yōu)良的PTFE中空纖維膜的擠出工藝參數(shù)。(3)拉伸和燒結(jié)工藝對PTFE中空纖維膜微孔結(jié)構(gòu)性能的影響規(guī)律如下:隨著拉伸倍數(shù)的增加,PTFE中空纖維膜的平均孔徑、孔隙率大,泡點壓強小,水通量大;隨著拉伸溫度的增加,PTFE中空纖維膜的平均孔徑、水通量增大,孔隙率增加,泡點壓強降低;隨著燒結(jié)溫度的增加,PTFE中空纖維膜的孔徑,泡點壓強、水通量降低,孔隙率無明顯變化規(guī)律;隨著燒結(jié)時間的增加,PTFE中空纖維膜平均孔徑、孔隙率、水通量增加,泡點壓強降低。拉伸工藝使PTFE制品的結(jié)晶度明顯降低,燒結(jié)工藝使PTFE制品的結(jié)晶度進(jìn)一步降低。在拉伸倍數(shù)100%、拉伸溫度300℃、燒結(jié)溫度320℃和燒結(jié)時間5min時,得到的中空纖維膜平均孔徑小,泡點壓強、孔隙率、水通量大。
[Abstract]:Hollow fiber membrane is widely used in ultrafiltration, microfiltration, reverse osmosis, gas separator and other traditional and new membrane separation module forms because of its small area, high filling density, high utilization ratio, easy amplification, easy cleaning and other characteristics. In addition, the hollow fiber membrane membrane is widely used in ultrafiltration, microfiltration, reverse osmosis, gas separator and other traditional and new forms of membrane separation components. Due to its high mechanical strength, acid and alkali resistance, high and low temperature resistance and low surface friction coefficient, PTFE hollow fiber membrane is used in special filtration, gas absorption, ozone dissolution filtration, etc. The application potential of membrane distillation is great [3]. In this paper, the polytetrafluoroethylene dispersion resin is used as raw material and ExxonMobil iso-alkane series Isopar lubricant is added. PTFE hollow fiber membrane was prepared. Extrusion average pressure, pore size and bubble point pressure, porosity, water flux were used. The structure and properties of PTFE hollow fiber membrane were characterized by contact angle scanning electron microscopy (SEM) and DSC. The effects of lubricant (type and proportion), extrusion process (compression ratio, aspect ratio and cone angle) and tensile sintering process on the structure and properties of PTFE were investigated. The process parameters are optimized to provide guidance for the production of PTFE hollow fiber membrane. The specific research contents are as follows: 1. The experiment changes the lubricant parameters (including lubricant type, ratio of lubricant), through "mixing" 鈫扨reforming. 鈫扙xtrusion. 鈫扴tretch. 鈫扴intering. 鈫扵he PTFE hollow fiber membrane was prepared by natural cooling process. The effects of lubricant type and ratio on the structure and properties of PTFE hollow fiber membrane were investigated in the experiment. The optimum combination of lubricant type and ratio was obtained. By changing the die parameters of extrusion process, the influences of compression ratio (RR), ratio of length to diameter (L / D), angle 偽 on extrusion pressure, film breaking strength, average pore size, bubble point pressure, porosity and water flux were investigated. The optimum extrusion parameters were obtained by adjusting the drawing process parameters (drawing ratio and drawing temperature) and sintering process parameters (sintering temperature and sintering time) to investigate the average pore size and bubble point pressure of PTFE hollow fiber membrane by drawing sintering process. The effects of porosity and water flux on the properties of PTFE hollow fiber membrane were studied. The optimum drawing sintering process parameters were obtained. The experimental results showed that the average pore size of PTFE hollow fiber membrane was small when the type of lubricant was Isoparg and the ratio of 20% was 20%. When the foam point pressure and porosity are high, the water flux is large, the contact angle is high and the extrusion pressure is low, the lubricant content is too high or too low. The structure and properties of PTFE hollow fiber membrane were affected to some extent. 2) when the compression ratio RRN 1855, the aspect ratio L / D 20, and the angle 偽 40 擄, the extrusion pressure was low, the fracture strength was large, the average pore size was small, the bubble point pressure was high, and the porosity was large. The effect of high water flux on the micropore structure and properties of PTFE hollow fiber membrane is as follows: with the increase of drawing ratio, the average pore size of PTFE hollow fiber membrane is increased. With the increase of tensile temperature, the average pore size of PTFE hollow fiber membrane increases, the water flux increases, the porosity increases and the bubble point pressure decreases, and with the increase of sintering temperature, the pore size of PTFE hollow fiber membrane increases. With the increase of sintering time, the average pore size, porosity and water flux of PTFE hollow fiber membrane increased, and the pressure of foam point decreased. The crystallinity of PTFE products was further reduced by sintering process. When drawing ratio 100, drawing temperature 300 鈩，

本文編號：1501931