本文選題：聚丙烯　切入點(diǎn)：熱致相分離　出處：《上海大學(xué)》2016年博士論文

【摘要】：聚丙烯(PP)中空纖維膜因其具有良好的化學(xué)穩(wěn)定性和熱穩(wěn)定性,且價(jià)格低廉,處理效率高,已經(jīng)被廣泛應(yīng)用于膜蒸餾、工業(yè)廢水及市政污水處理、飲用水凈化等領(lǐng)域。由于PP為非極性結(jié)晶聚合物,常溫下無合適溶劑,因此只能采用熔紡-拉伸法(MSCS)和熱致相分離法(TIPS)制備中空纖維膜,其中TIPS法制備PP中空纖維微濾膜易實(shí)現(xiàn)對(duì)膜孔結(jié)構(gòu)調(diào)控。PP中空纖維膜結(jié)構(gòu)調(diào)控的關(guān)鍵因素是稀釋劑和PP之間的相互作用力,由于單一稀釋劑和PP作用力強(qiáng),制備的膜一般為球狀粒子結(jié)構(gòu),強(qiáng)度低,皮層厚,通量小,不適合用于水處理。本論文采用組合稀釋劑通過TIPS法制備PP中空纖維膜,成功的實(shí)現(xiàn)了對(duì)PP中空纖維膜孔結(jié)構(gòu)的調(diào)控,并對(duì)PP進(jìn)行了多種親水改性,制備了具有親水性的PP中空纖維膜。研究TIPS法制備PP中空纖維膜聚合物濃度、組合稀釋劑與PP的相互作用力、制膜工藝參數(shù)等因素與中空纖維膜結(jié)構(gòu)和性能之間的關(guān)系。膜絲強(qiáng)度結(jié)果表明在組合稀釋劑DS/GA體系下PP含量為20%較為合適。等溫冷卻過程為L(zhǎng)-L(液-液)分相的噴絲液在TIPS法制備PP中空纖維膜過程中由于冷卻速率快,體系易直接進(jìn)入結(jié)晶區(qū)域而出現(xiàn)S-L(固-液)分相,所得的結(jié)構(gòu)為球狀粒子結(jié)構(gòu)。通過提高氣隙長(zhǎng)度來降低冷卻速率,出現(xiàn)了L-L相分離的網(wǎng)狀孔結(jié)構(gòu),說明非等溫冷卻動(dòng)力學(xué)過程對(duì)噴絲液體系分相過程的影響較大。在常溫水浴冷卻下,聚合物濃度為20%,組合稀釋DS/GA質(zhì)量比為10:5~10:6之間的噴絲液體系發(fā)生了相分離形式的轉(zhuǎn)變,由S-L相分離到L-L相分離的轉(zhuǎn)變,膜孔結(jié)構(gòu)也出現(xiàn)明顯的球狀粒子-網(wǎng)狀孔-蜂窩空結(jié)構(gòu)的轉(zhuǎn)變。同時(shí)發(fā)現(xiàn)芯液與噴絲液的傳質(zhì)會(huì)影響內(nèi)皮層的開孔性;噴絲液中水溶性溶劑的加入也會(huì)改善噴絲液與凝固浴的傳質(zhì),從而改善外皮層的開孔性。通過TIPS法制備了PP親水改性中空纖維膜。試結(jié)果表明,含5份聚醚醇類親水改性劑HL560的PP的水接觸角降低到20°左右,但浸泡后會(huì)提高到60°以上。為解決水處理過程中親水改性劑流失問題,采用駐留劑EAA鈉鹽和親水改性劑復(fù)配改性PP,親水改性PP的親水性能明顯提高并能長(zhǎng)時(shí)間保持。膜的純水通量由原來的122 l/m2h提高到200 l/m2h。此外,EAA鈉鹽的加入會(huì)輕微影響PP的結(jié)晶性能,改性膜的結(jié)構(gòu)稍微有所改變,但影響不大。通過DSC、XRD等方法研究了PP/PA6合金的非等溫結(jié)晶動(dòng)力學(xué),從而研究了PA6的加入對(duì)PP結(jié)晶性能的影響,為TIPS法制膜提了供理論依據(jù)。實(shí)驗(yàn)結(jié)果表明無定型PA6和PP共混,PA6含量25wt%,以10%wt的PP-g-MAH作為相容劑制備的PP/PA6合金,相容性優(yōu)良,幾乎沒有改變PP的結(jié)晶性能,還促進(jìn)了PP的β晶形成。制備的PP/PA6合金中空纖維膜在PA6含量為25wt%以下時(shí),結(jié)構(gòu)幾乎和PP膜相同,親水性能明顯改善,膜絲強(qiáng)度也有所提高。
[Abstract]:Polypropylene (PP) hollow fiber membrane due to its good thermal and chemical stability, and low price, high processing efficiency, has been widely used in membrane distillation, industrial wastewater and municipal wastewater treatment, drinking water purification and other fields. Since PP is a non polar crystalline polymer, no suitable solvent at room temperature, it can only be by melt spinning stretching (MSCS) and thermally induced phase separation (TIPS) preparation of hollow fiber membrane, the preparation of TIPS PP hollow fiber microfiltration membrane is easy to realize the key factors on the membrane pore structure control of.PP hollow fiber membrane structure regulation is the interaction between the dilution agent and PP, due to the single diluent and PP the force is strong, the membrane prepared is generally spherical particle structure, low intensity, cortical thickness, small flux, not suitable for water treatment. The preparation of PP hollow fiber membrane by TIPS method using a combination of diluent, the successful implementation of the PP hollow fiber The regulation of fiber membrane pore structure, and the PP in a variety of hydrophilic modification of PP hollow fiber membrane with a hydrophilic preparation. Study on Preparation of TIPS PP hollow fiber membrane polymer concentration, diluent and PP combination of interaction, the relationship between the structure and the performance of the membrane preparation process parameters and hollow fiber membrane the membrane strength. The results show that the combination of thinner DS/GA system 20% PP content is more appropriate. The isothermal cooling process for L-L (liquid) liquid phase in TIPS spinning preparation of PP hollow fiber membrane process due to the rapid cooling rate, easy system directly into the crystal region and S-L (solid and liquid) the phase structure of spherical particle structure. To reduce the cooling rate by increasing the length of air gap, the mesh pore structure of L-L phase separation, that influence the kinetics of non isothermal cooling spray fluid system greatly. The process of phase separation in water at room temperature The cooling bath, the polymer concentration is 20%, combination of dilution DS/GA mass ratio of spinneret fluid system between 10:5~10:6 phase separation occurred in the form of change, the phase separation of S-L into L-L phase separation, membrane pore structure also appears spherical particles - obvious netted hole honeycomb hollow structure change. At the same time that mass transfer the core liquid and the spinning liquid will affect the endothelial layer hole of spinneret; join the water soluble solvent will improve the mass transfer of spinneret and coagulation bath liquid, thereby improving the outer layer hole. TIPS PP was prepared by hydrophilic hollow fiber membrane. The test results show that containing 5 copies of polyether alcohols hydrophilic modifier HL560 PP water contact angle decreased to about 20 degrees, but after immersion will increase to more than 60 degrees. In order to solve the water treatment process of hydrophilic agent loss, the resident agent EAA sodium and hydrophilic agent modified PP hydrophilic hydrophilic modification PP The performance improved significantly and can keep a long time. The pure water flux increased from 122 l/m2h to 200 l/m2h. in addition, adding EAA sodium will slightly affect the crystallization of PP, the structure of the modified membrane slightly changed, but the effect is not obvious. By DSC, the non isothermal crystallization kinetics of XRD PP/PA6 alloy have been studied. Thus, the effect of PA6 on the crystallization of PP, provide a theoretical basis for the TIPS technique. The experimental results show that the amorphous PA6 and PP blend, the content of PA6 25wt%, 10%wt PP-g-MAH PP/PA6 alloy as compatibilizing agent preparation, excellent compatibility, almost no change in the crystallinity of PP also. Promote the beta crystal formation of PP alloy. PP/PA6 hollow fiber membrane prepared in the PA6 content of 25wt%, PP and almost the same membrane structure, hydrophilic properties improved significantly, the membrane strength is also improved.

【學(xué)位授予單位】：上海大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類號(hào)】：TQ051.893

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 于曉強(qiáng),王靜媛,李峰,秦東奇,徐冰,湯心頤;馬來酸酐接枝聚丙烯的等溫結(jié)晶動(dòng)力學(xué)研究[J];高分子學(xué)報(bào);1998年01期

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本文編號(hào)：1688400