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以二羟甲基丙酸(DMPA)作为亲水单体,采用甲苯二异氰酸酯(TDI)、聚酯二元醇(PCDL)为原料,于水性介质中在偶联剂水杨醛的作用下,制备了聚氨酯/明胶共聚物,用傅里叶变换红外光谱(FTIR)分析及凝胶渗透色谱分析(GPC)证实了该共聚反应的发生;研究结果表明,DMPA质量分数为5%时,可得到稳定的聚氨酯乳液,此时胶膜的吸水率为8.52%;热重分析(TGA)显示,共聚物胶膜在240℃开始分解;示差扫描量热分析(DSC)显示,经改性后共聚物的玻璃化温度(Tg)为66℃;X射线衍射分析(XRD)表明,聚氨酯的加入使共聚物胶膜的结晶度大大降低,在聚氨酯质量分数为50%时,共聚物的结晶度降为2%;力学性能分析及耐水性测试表明,当聚氨酯质量分数从0%到50%变化时,胶膜的抗张强度由83 MPa下降到37.3 MPa,断裂伸长率从25.5%增大到325.6%,当聚氨酯质量分数从10%到50%变化时,胶膜的吸水率从251%下降到65%。
Using dimethylol propionic acid (DMPA) as hydrophilic monomer, using toluene diisocyanate (TDI) and polyester diol (PCDL) as raw materials in the aqueous medium under the action of coupling agent salicylaldehyde, The polyurethane / gelatin copolymer was prepared and the copolymerization reaction was confirmed by Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC). The results showed that when the mass fraction of DMPA was 5% Stable polyurethane emulsion, the moisture absorption rate of the film was 8.52%; TGA showed that the copolymer film began to decompose at 240 ℃; Differential Scanning Calorimetry (DSC) showed that the modified copolymer (Tg) of 66 ℃; X-ray diffraction analysis (XRD) shows that the addition of polyurethane makes the copolymer film significantly reduce the crystallinity of the polyurethane mass fraction of 50%, the copolymer crystallinity reduced to 2%. The mechanical properties and water resistance test show that when the mass fraction of polyurethane increases from 0% to 50%, the tensile strength of the film decreases from 83 MPa to 37.3 MPa and the elongation at break increases from 25.5% to 325.6% %, When the polyurethane mass fraction changes from 10% to 50%, the water absorption of the film drops from 251% to 65%.