热诱导相分离法制备亲水性乙烯-丙烯酸共聚物微孔膜

FORMATION OF HYDROPHILIC ETHYLENE-ACRYLIC ACID COPOLYMER MICROPOROUS MEMBRANES VIA THERMALLY INDUCED PHASE SEPARATION

选择 3种不同丙烯酸含量的乙烯 丙烯酸共聚物 (EAA)为原材料 ,二苯醚 (DPE)为稀释剂 ,采用热诱导相分离法 (TIPS)制备了亲水性高分子微孔膜 .接触角实验证明 ,EAA为亲水性高分子材料 .利用熔点仪根据浊度的变化测绘出 3种不同EAA/DPE体系的双结点线以及通过DSC得出相应 3体系的结晶温度曲线 .实验结果还表明 ,随着乙烯 丙烯酸共聚物中丙烯酸含量的增加 ,结晶温度曲线向低温方向移动 ,相对应的膜孔直径也增加 .此外 ,随着EAA DPE体系中EAA初始浓度的逐渐增加 ,膜孔直径逐渐变小 ,当体系中EAA初始浓度高于 5 0 %时 。

Hydrophilic microporous membranes were prepared via the TIPS process using three hydrophilic ethylene-acrylic acid co-polymers with different co-unit contents and diphenyl ether. These co-polymer were confirmed to the hydrophilic by contact angle measurements. Cloud points were determined visually by noting the appearance of turbidity under the microscope. The relevant crystallization temperatures for the thermodynamic phase diagram were determined by differential scanning calorimetry (DSC). The crystallization temperature curves shifted to lower temperatures as the amorphous acrylic acid content of the co-polymer increased. The membrane structures were investigated by scanning electron microscope and related to the initial polymer concentration and acrylic acid content. As the polymer concentration increased or the acrylic acid content decreased, the pore size decreased. However, at the concentration above 50 wt%, the films had no microporosity.