含羧基高分子共混聚醚砜超滤膜亲水化改性研究

论文总字数：33346字

摘 要

工业的快速发展，产生了大量的含油废水。传统分离技术处理含油废水时存在着或多或少的缺点，膜分离技术以其高效、绿色、环保的特点，被认为是处理含油废水最有效的方法。

聚醚砜（PES）膜具有良好的热稳定性、良好的化学稳定性的特点，并具有高强度，是理想的超滤膜材料，但是PES膜具有较强的疏水性，导致其容易受到膜污染，会引起膜性能的下降。所以本课题选择对聚醚砜超滤膜进行亲水化研究。

利用可逆加成-断裂链转移聚合（RAFT）方法以丙烯酸（AA）和F127（F127，PEO-B-PPO-B-PEO）设计并合成了改性嵌段聚合物PAA-F127-PAA，通过红外光谱、核磁共振氢谱对嵌段共聚物进行表征。并考察了物料比、温度、和反应时间对嵌段聚合物亲水性的影响，结果表明：合成温度越高，高聚物分子量越大，亲水性越强,70℃为最佳温度；大分子链转移剂含量越多，高聚物分子量越小，亲水性越弱，最佳物料比AA:CPADB-F127-CPADB:AIBN为160:0.5:0.2；反应时间越长，亲水性越强，最佳反应时间为8h。PAA-F127-PAA与PES共混成膜，达到增强亲水性进而提高抗污染性能的目的。并在共混成膜过程中考察了温度、物料比对膜性能和结构的影响，相比于未改性PES膜：改性膜的孔隙率和表面孔径更大，孔隙率由45.23%变化到60.8%；改性膜的水通量、油通量更大，水通量从64.10L/m²h变化到了178.93L/m²h，油通量从11.09L/m²h变化到了76.45L/m2h，随温度的增大，水通量从64.10L/m²h变化到203.56L/m²h，油通量从11.09L/m²h变化到87.89L/m²h；改性膜的水接触角更小，水接触角随着改性物含量的增加从84.5°减小到67.7°；改性膜的截留率正常温度下保持不变，随着温度升高截留率从100%降低到85%；改性膜的恢复率更大，且随着改性物含量的增加从46%变化到84%。

关键词：含油废水处理，RAFT，物理共混，亲水性，抗污染性能。

A STUDY ON HYDROPHILIC MODIFICATION OF PES ULTRAFILTRATION MEMBRANE CONTAINING CARBOXYL GROUP

Abstract

The rapid development of industry has produced a lots of oily wastewater. The traditional separation technologies have more or less drawbacks while membrane separation technology is environmental friendly,green and with high efficiency,so membrane separation technology is considered as the most effective way to deal with oily wastewater.

Poly (ether ether ketone) (PES) membrane is considered to be an ideal ultrafiltration membrane material with high thermal stability, good chemical stability and high strength.,but PES membrane is prone to membrane fouling because of its strong hydrophobicity which will lead to a deciline in the performance of membrane So we choose the PES UF membrane to have a hydrophilic modification.

We use RAFT method to design and synthetize the modified block polymer PAA-F127-PAA withAA and F127,and we will characterize it with IR and 1HNMR.We study the effect of material ratio,temperature, and reaction time on the hydrophilicity of block polymer. Result shows: The higher the synthesis temperature, the higher the molecular weight, the stronger the hydrophilicity and the optimum temperature is 70℃. The more macro-chain transfer agents, the lower the molecular, the weaker the hydrophilicity and the optimum material ratio of AA:CPADB-F127-CPADB is 160:0.5:0.2. The longer the reactiong time,the higher the molecular weight and the optimal reaction time is 8h. We blend PAA-F127-PAA and PES to obtain membrane to achieve the goal of the increase of hydrophily to enhance the capacity of anti-fouling.And we discuss the effect of temperature, material ratio on membrane property and structure during the blending process.Result shows compared with unmodified PES membrane: The modified membranes have biger porosity and surface pore size, the porosity changes from 45.23% to 60.8%. The modified membranes have larger water flux and oil flux, water flux changes from 64.10L/m²h to 178.93L/m²h, and oil flux changed from 11.09L/m²h to 76.45L/m²h. And the water flux changes from 64.10L/m²h to 203.56L/m²h, the oil flux changes from 11.09L/m²h to 87.89L/m²h when the temperature increases. The modified membranes have smaller water contact angle, Water contact angle decreases from 84.5°to 67.7° with the increase of the content of the modified substance. The rejection rate of the modified membranes remains the same ,and it decreases from 100% to 85%with the increase of temperature. The recovery rate of the modified membrane is larger, and it will increase 46% to 84% with the increase of the content of the modified substance.

Key words: The treatment of oily wastewater, RAFT, physical blending, hydrophilicity, anti fouling property.

目录

摘 要 3

Abstract 4

第一章 绪论 8

1.1引言 8

1.2 膜分离技术 8

1.2.1 膜分离的概念 8

1.2.2 膜分离的基本原理 8

1.2.3 膜的性能表征 9

1.2.4 分离膜的材料 9

1.2.5 分离膜的制备和改性 9

1.2.5.1 聚合物分离膜的制备 10

1.2.5.2 无机膜的制备 10

1.2.5.3 常见的膜改性方法 10

1.2.6 常见的膜分离过程 11

1.2.6.1 微滤 11

1.2.6.2 超滤 11

1.2.6.3 纳滤 11

1.2.6.4 反渗透 12

1.2.7 膜分离过程的应用 12

1.2.7.1 在化工方面的应用 12

1.2.7.2 在生物医学方面的应用 12

1.2.7.3 在食品方面的应用 13

1.2.7.4 在水处理方面的应用 13

1.3 含油废水处理 13

1.4 本课题的选题背景和研究内容 15

第二章 嵌段共聚物的合成 17

2.1实验药剂 17

2.2 嵌段共聚物PAA-F127-PAA的合成 17

2.2.1 合成小分子链转移剂4-氰基戊酸二硫代苯甲酸（CPADB） 17

2.2.1.1 合成二硫代苯甲酸钠 17

2.2.1.2 合成双二硫代苯甲酰 17

2.2.1.3 合成4-氰基戊酸二硫代苯甲酸 17

2.2.2 合成大分子链转移剂CPADB-F127-CPADB 18

2.2.3 合成嵌段共聚物PAA-F127-PAA 18

2.2.4 对添加剂PAA-F127-PAA的表征 19

2.2.4.1 傅里叶变换红外光谱（FT-IR）分析 19

2.2.4.2 核磁共振氢谱（¹H-NMR）分析 19

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