反应诱导相分离法制备多孔聚合物材料

发布时间：2018-06-28 09:38

本文选题：反应诱导相分离 + 多孔材料　；参考：《北京化工大学》2010年博士论文

【摘要】： 反应诱导相分离法(Chemically induced phase separation)制备多孔聚合物材料,是在固化反应开始之前,溶剂或热塑性塑料与热固性树脂混合均匀后,体系处于均相状态。随着固化反应的进行,热固性树脂的分子量逐渐增加,与溶剂或热塑性塑料之间的相容性逐渐变差,体系在热力学上不再相容,相分离开始发生,相结构逐步演化并粗大化。固化产物经洗涤干燥将溶剂去除后或使热塑性塑料高温降解即可得到多孔结构的聚合物材料。与其它制备多孔材料方法相比,工艺简单易操作,可以控制孔径大小及分布。本文主要工作如下： 1.利用反应诱导相分离法,以环氧大豆油为溶剂,双酚A环氧树脂为单体,4,4-二氨基二苯甲烷为固化剂制备多孔环氧树脂。研究了环氧树脂最终相态取决于环氧基体与环氧大豆油的组成,并通过光学显微镜对其相分离过程进行跟踪。在相态由分散孔向相反转结构转变时,体系均遵循旋节线降解机理；当环氧大豆油浓度较低时,得到了环氧树脂的闭孔结构。研究了溶剂浓度、固化剂用量,固化温度对多孔结构的影响,环氧大豆油浓度增加,孔径增大,分布变宽,密度降低,孔隙率增大。增加固化剂用量,提高固化温度,加快固化反应速率,得到较大孔径的环氧结构。 2.采用热塑性塑料通过反应诱导相分离法制备了多孔环氧树脂。脂肪族聚碳酸酯作为热塑性塑料,与环氧树脂制得复合材料,使脂肪族聚碳酸酯高温降解即得到环氧树脂多孔结构。利用固化时间-脂肪族聚碳酸酯质量浓度的准相图描述了环氧树脂／热塑性塑料体系的相分离机理,并利用光学显微镜对相分离演化过程进行了跟踪。相分离机理受控于环氧树脂与脂肪族聚碳酸酯的组成,在脂肪族聚碳酸酯浓度较低时,遵循成核生长,反之,旋节线降解机理。随脂肪族聚碳酸酯浓度增加,环氧树脂／脂肪族聚碳酸酯体系经历了分散相-双连续相-相反转结构的转变。增加热塑性塑料浓度、提高固化温度,环氧树脂孔径增大。 3.对热塑性塑料的端羟基进行了环氧化反应,合成了环氧化脂肪族聚碳酸酯,并利用傅立叶红外光谱进行表征,其环氧值为6.8%。 4.将环氧化脂肪族聚碳酸酯作为热塑性塑料,通过反应诱导相分离法制备了多孔聚合物材料,得到孔隙率较大的多孔结构。在环氧树脂／环氧化脂肪族聚碳酸酯体系中,当环氧化脂肪族聚碳酸酯浓度较低时,制得分散较为均匀的多孔结构；随其浓度增加,孔径增大,分布变宽；在环氧化脂肪族聚碳酸酯浓度较高时,得到环氧微球,当环氧化脂肪族聚碳酸酯浓度介于两个临界浓度之间时,体系出现分层,上层和底层为分散孔结构,中间层为环氧微球。 5.通过光学显微镜研究了环氧树脂／环氧化脂肪族聚碳酸酯在不同固化温度下的相分离过程。当环氧化脂肪族聚碳酸酯浓度为35wt%时,环氧树脂／环氧化脂肪族聚碳酸酯体系在不同固化温度下均遵循旋节线降解机理,且环氧化脂肪族聚碳酸酯以分散相分布在环氧基体中。随固化温度升高,体系中环氧化脂肪族聚碳酸酯的粒径增大。
[Abstract]:A porous polymer material is prepared by reaction - induced phase separation , which is characterized by that the molecular weight of the thermosetting resin is gradually increased after the curing reaction is started , the compatibility between the solvent or the thermoplastic plastic is gradually deteriorated , the compatibility between the thermosetting resin and the solvent or the thermoplastic plastic is gradually deteriorated , and the system is not compatible with the solvent or the thermoplastic plastic gradually , and the polymer material with the porous structure is obtained after the solvent is removed or the thermoplastic plastic is high - temperature degradation .

1 . A porous epoxy resin was prepared by using epoxy soybean oil as solvent and bisphenol A epoxy resin as monomer , 4,4 - diamino diphenyl methane as curing agent . The final phase state of epoxy resin was determined by the composition of epoxy matrix and epoxidized soybean oil .
When the concentration of epoxy soybean oil is low , the closed pore structure of epoxy resin is obtained . The influence of solvent concentration , dosage of curing agent and curing temperature on porous structure is studied , the concentration of epoxy soybean oil is increased , the pore size is increased , the distribution becomes wider , the density is decreased , the porosity is increased , the curing temperature is increased , the curing reaction rate is increased , and the epoxy structure with larger pore size is obtained .

2 . A porous epoxy resin is prepared by reaction - induced phase separation by using thermoplastic plastics . The aliphatic polycarbonate is used as a thermoplastic material to prepare the composite material with epoxy resin . The phase separation mechanism of the epoxy resin / thermoplastic system is described by the quasi - phase diagram of the mass concentration of the aliphatic polycarbonate .

3 . The cyclic oxidation reaction was carried out on the hydroxyl groups of thermoplastic plastics . The epoxidized aliphatic polycarbonate was synthesized and characterized by FT - IR , and its epoxy value was 6.8 % .

4 . The porous polymer material was prepared by the reaction - induced phase separation method , and the porous structure with larger porosity was obtained .
As the concentration increases , the pore diameter increases and the distribution becomes wider ;
when the concentration of the epoxidized aliphatic polycarbonate is higher , the epoxy microspheres are obtained ; when the concentration of the epoxidized aliphatic polycarbonate is between two critical concentrations , the system is layered , the upper layer and the bottom layer are distributed pore structures , and the middle layer is epoxy microspheres .

5 . The phase separation process of epoxy resin / epoxidized aliphatic polycarbonate at different curing temperatures was studied by optical microscope . When the concentration of epoxidized aliphatic polycarbonate was 35 wt % , the epoxy resin / epoxidized aliphatic polycarbonate system followed the mechanism of spin - on - line degradation at different curing temperatures , and the epoxidized aliphatic polycarbonate was distributed in the epoxy matrix with dispersed phase .
【学位授予单位】：北京化工大学
【学位级别】：博士
【学位授予年份】：2010
【分类号】：O631.3

【参考文献】