聚醚型阳离子聚氨酯乳液流变性能及结构表征

Rheological Property and Structure Characterization of Polyether Cationic Polyurethane Emulsion

以聚四氢呋喃醚(PTMG1000)为软段,N-甲基二乙醇胺(MDEA)为阳离子扩链剂,三羟甲基丙烷(TMP)为内交联剂合成了阳离子聚氨酯(CPU)乳液;结合平均粒径分析,系统研究了R(nNCO/nOH)值、MDEA用量、TMP用量等因素对该乳液流变性能的影响;采用IR,TEM,TG等分析测试技术,对CPU结构进行了表征.结果表明:在1.30～1.50之间,随着R值增大,CPU乳液平均粒径增大,黏度降低;在质量分数6.45%～10.60%之间,随着MDEA用量的增加,CPU乳液平均粒径减小,黏度增大;在质量分数0～3.20%之间,随着TMP用量的增加,CPU乳液粒径先减小后增大,黏度先升高后降低.在不同合成条件下,CPU乳液的幂律指数n为0.972～0.998,基本上属于牛顿流体.CPU为软、硬段微相分离结构,且TMP的加入使该微相分离程度加大.

A series of polyether cationic polyurethane（CPU） emulsions were prepared by using polytetrahydrofuran glycol（PTMG1000） as soft segment,N-methyl diethanol amine（MDEA） as cationic chain-extender and trimethylolpropane（TMP） as crosslinker.The influences of R（nNCO/nOH）,the content of MDEA and TMP on the rheology of the CPU emulsion were studied.The structure of the CPU was characterized by IR,TEM and TG.The results show that the particle size of the CPU emulsion increases,and its apparent viscosity decreases with R increasing between 1.30-1.50 and the content of MDEA decreasing between 10.60%-6.45%.The particle size and the apparent viscosity of the CPU emulsion take on complex change with the content of TMP increasing between 0-3.20%.The study indicates that the flow-behavior index（n） of the CPU emulsions ranges from 0.972 to 0.998,and they exhibit the behavior of Newtonian fluids approximately.The characteristic infrared groups of CPU are characterized by IR.TEM micrograph shows that the morphology of CPU particle is spherical.TGA data indicates that there is microphase separation in the CPU,and the microphase separation degree of CPU increases with increasing content of TMP.