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以不同分子量聚乙二醇(PEG)、4,4’-二苯基甲烷二异氰酸酯(MDI)、1,4-丁二醇(BDO)为原料,采用两步法合成了一系列聚氨酯类材料。通过热重分析(TG)、傅立叶红外光谱仪(FT-IR)确定其化学组成,通过偏光显微镜(POM)、X射线衍射(XRD)进行了材料形态结构分析。同时,改变聚乙二醇在材料中所占质量分数得到一系列材料,利用差示扫描量热分析(DSC)发现随聚乙二醇分子量增大,材料相变焓增大,相变温度升高。考察其相变行为发现当聚乙二醇所占质量分数低于91%时,材料呈固-固相变,相变过程为晶态-无定型态的一级相变,且随聚乙二醇质量分数增加,相变焓增加,硬度降低,拉伸强度增加。
A series of polyurethane materials were synthesized by two-step method using polyethylene glycol (PEG), 4,4’-diphenylmethane diisocyanate (MDI) and 1,4-butanediol (BDO) . The chemical composition was determined by thermogravimetric analysis (TG) and Fourier transform infrared (FT-IR) spectroscopy. The morphological structure of the material was analyzed by POM and XRD. At the same time, changing the mass fraction of polyethylene glycol in the material to obtain a series of materials, using differential scanning calorimetry (DSC) found that with increasing molecular weight of polyethylene glycol, the material enthalpy increases, the phase transition temperature rise high. The phase transition behavior was investigated. The results showed that when the mass fraction of polyethylene glycol is less than 91%, the material is in the solid-solid phase, the phase transition is the first-order phase transition in the crystalline-amorphous state, The diol mass fraction increased, the enthalpy of phase change increased, the hardness decreased, and the tensile strength increased.