摘要利用热致相分离原理制备PVDF微孔膜。通过选择合适的稀释剂、合理调节混合稀释剂组成比以及选择适宜的聚合物初始浓度等来研究PVDF/邻苯二甲酸二丁酯(DBP)/邻苯二甲酸二己酯(DEHP)三元体系,观察体系结晶温度、熔融温度、相分离形态等热力学行为。在单一稀释剂DBP下,体系结晶温度与熔融温度随着聚合物初始浓度提高而上升;在冷却降温过程中发生固液分离,产生球晶结构。在混合稀释剂DBP/DEHP下,体系结晶温度和熔融温度随着DEHP的加入而上升;在冷却降温过程中,DBP/DEHP=0.5体系发生液液相分离而出现密集小液滴,DBP/DEHP>0.5体系发生固液分离。选择一定条件下制备的PVDF微孔膜,有一定水通量,机械强度有待提高。5739
关键词 热致相分离 PVDF微孔膜 混合稀释剂 结晶温度 熔融温度
毕业设计说明书(论文)外文摘要
Title Preparation of PVDF porous membrane via thermally induced phase separation ---- DBP/DEHP system
Abstract
The PVDF porous membranes were prepared via thermally induced phase separation. The phase behavior of a ternary system of poly(vinylidene fluoride)(PVDF), dibutyl phthalate(DBP) and di(2-ehylhexyl) phthalate(DEHP) was determined by observing the melting temperature, crystallization temperature and phase separated structure. In the system of single diluent DBP, the melting temperature and crystallization temperature increased as the polymer initial concentrations rose and the solid-liquid separation occurred in the process of cooling, resulting in the formation of spherulites structure. In the system of mixture diluent of DBP/DEHP, the melting temperature and crystallization temperature increased with the addition of DEHP, and liquid-liquid separation occurred and resulted in the structure of intensive small droplets at the ratio of 0.5 during cooling. When the ratio is over 0.5, the solid-liquid separation occurred instead of liquid-liquid separation. Under certain circumstances, the PVDF flat membranes were prepared with reasonable polymer initial concentration and mixture diluents ratio. It is found that the mechanical strength and water flux needed to be improved.
Keywords Poly(vinylidene fluoride)(PVDF) porous membranes Thermally induced phase separation Dibutyl phthalate(DBP) Di(2-ehylhexyl) phthalate(DEHP) Phase behavior
目次
1 绪论 1
1.1 PVDF微孔膜 1
1.1.1 PVDF微孔膜性质简介 1
1.1.2 PVDF微孔膜制备方法 1
1.2 热致相分离法 2
1.2.1 热致相分离法简介 2
1.2.2 热致相分离法制膜方法 2
1.2.3 热致相分离法优缺点 2
1.3 热致相分离制备微孔膜的热力学基础 3
1.4 热致相分离制备PVDF微孔膜的应用及研究进展 4
1.5 论文研究思路及研究内容 6
2 实验部分 7
2.1 实验原料与仪器 7
2.1.1 实验原料与试剂 7
2.1.2 实验仪器 7
2.2 实验方法 8
2.2.1 PVDF/稀释剂体系热力学相分离研究 8
2.2.1.1 聚合物/稀释剂混合物样品制备 8
2.2.1.2 结晶温度和熔融温度测定 8
2.2.1.3 相分离形态观察 9
2.2.2 PVDF微孔平板膜的制备 9
2.2.3 PVDF微孔膜性能表征 10
2.2.3.1 水通量测定 10 热致相分离法制备PVDF微孔膜的研究DBP/DEHP体系:http://www.youerw.com/huaxue/lunwen_2906.html