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以聚乙二醇(PEG)、异佛尔酮二异氰酸酯(IPDI)和十六醇(CA)为原料,采用逐步聚合法,合成了一系列不同相对分子质量和组成的两亲性脂肪族聚氨酯。提出了一种利用核磁共振氢谱(~1H NMR)测定时不需要定量加入标准物质即能得到两亲性聚氨酯的相对分子质量和组成的方法。该实验方法简单,对样品没有破坏。利用该方法定量测定了系列聚氨酯的相对分子质量和组成,同时得到聚氨酯预聚体两端的NCO基团与十六醇中的OH基团的反应程度,即疏水链段的封端率。测得的聚氨酯系列样品数均相对分子质量与理论相对分子质量比较接近,得到了准确的定量结果,且样品的封端率比较高(≥72%)。
Polyethylene glycol (PEG), isophorone diisocyanate (IPDI) and cetyl alcohol (CA) were used as raw materials to synthesize a series of amphiphilic aliphatic polyurethanes with different relative molecular mass and composition . A method for obtaining the molecular weight and composition of amphipathic polyurethanes without the need of quantitative addition of a standard substance was proposed by using 1H nuclear magnetic resonance spectroscopy (~ 1H NMR). The experimental method is simple, the sample is not damaged. The relative molecular mass and composition of the series of polyurethanes were quantitatively determined by this method. The degree of reaction between the NCO groups at both ends of the polyurethane prepolymer and the OH groups in cetyl alcohol, that is, the blocking rate of the hydrophobic segments, was also obtained. The number-average molecular weight of the polyurethane samples measured was close to the theoretical relative molecular mass, accurate quantitative results were obtained, and the blocking ratio of the samples was relatively high (≥72%).