不同聚乙二醇相对分子质量的聚碳酸酯聚氨酯的防水透湿性

Effect of Polyethylene Glycol Molecular Weight on the Structure and Waterproof Properties of Polycarbonate Based Polyurethane

采用不同相对分子质量的聚乙二醇(PEG)分别与聚碳酸酯二元醇(PCDL)、二苯基甲烷二异氰酸酯(MDI)反应,合成了一系列聚碳酸酯聚氨酯(PU)。通过差示扫描量热分析、红外光谱分析、原子力显微镜分析等研究了不同相对分子质量的PEG对聚碳酸酯聚氨酯的形态结构和防水透湿性的影响。研究结果表明,分子链中引入PEG后,PU软段的Tg逐渐下降,且PU软硬段均不结晶。随着PEG相对分子质量的提高,PU微相分离程度先减小后增大,PU的亲水性提高,透气性先减小后增大。

A series of polycarbonate based polyurethane（ PU） were synthesized with different molecular weight polyethylene glycol（ PEG）,polycarbonate diol（ PCDL） and diphenyl methane diisocyanate（ MDI）. The effect of different PEG molecular weight on the structure,morphology,water vapor permeability and mechanical properties of polyurethane based on polycarbonate were studied by differential scanning calorimeter（ DSC）,FT-IR,atomic force microscope（ AFM） etc. The results show that,when PEG is introduced into the PU,the crystalline structure of soft segment and hard segment in the PU are damaged,and Tgof soft segments in the PU decreases. With the increase of the molecular weight of PEG in the PU,the degree of micro-phase separation in the PU initially decreases and then increases. The hydrophilicity of PU is improved,while the water vapor permeability of PU reduces firstly and then improves.