聚氨酯乳液的制备与稳定性分析

按照丙酮路线,以异弗尔酮二异氰酸酯（IPDI）、聚丙二醇-1000（PPG-1000）和二羟甲基丙酸（DMPA）等为原料设计和制备了以异氰酸酯（—NCO）封端,二羟甲基丙酸的质量分数分别为2.1%、4.2%、6.4%和8.6%不同分子量的聚氨酯。傅里叶红外变换光谱（FT-IR）的吸收峰与聚氨酯分子中的官能团特征吸收峰一致;聚合物的凝胶渗透色谱仪（GPC）分析表明：聚合物的分子量分别为3 450、6 700、8 600与13 500 g/mol,分子量（MW）对应密度函数（dw/dlgMW）曲线呈正态单峰窄分布。分析了不同含量的二羟甲基丙酸（DMPA）聚合物乳液的稳定性,结果表明：在重力场和离心力场下,二羟甲基丙酸含量越高,乳胶粒的亲水基团含量越高,聚合物的乳胶粒径和分布宽度越小,乳胶粒ζ电位的绝对值越大,乳液越稳定。

Analysis on Preparation and Stability of Polyurethane Emulsion

A series of polyurethane was prepared via acetone process from 3 -isocyanatomethyl -3,5,5 -trimethylcyclohexyl isocyanate（IPDI）,polypropylene glycol- 1000 （PPG- 1000） and dimethylol propionic acid（ DM- PA）. In the polyurethane chains,DMPA mass content were 2.1,4.2,6.4 and 8.6% with isocyanate（ - NCO） as capping agent. According to fourier transform infrared spectroscopy （ FT - IR）, the characteristic absorb peaks in the spectrum was agreed with the functional group in polyurethane chains. The number average molecular weight of those based on gel permeation chromatography （GPC）analysis were 3 450,6 700,8 600 and 13 500 g/mol,respec- tively. In the GPC curves, the function of molecular weight to the molecular weight density was narrow single peak with a normal distribution. Polyurethane emulsions stability was studied by comparing with DMPA content in the gravitational field and the centrifugal force field. The results indicated that particles size and its distribution decreased with increasing DMPA content, while the content of hydrophilic group and the absolute value of the latex particles potential became greater.