超支化聚氨酯/聚氨酯共混膜的制备及其性能研究

Study on the preparation and properties of HBPU/PU blend films

采用物理复配的方法,将含活性氨基的超支化聚氨酯(HBPU)与合成革用面层PU树脂进行共混,在一定条件下制成干法膜.研究了不同超支化聚氨酯的用量对干法膜吸水率、透湿率、透水汽性、及力学性能的影响,并用原子力显微镜观察了薄膜表面形貌变化,扫描电镜观察了膜结构的变化.结果表明:当HBPU用量为10%时,薄膜的吸水率由0.79%增至2.07%,透湿量由94.314g/(m2·d)增大至471.570 2g/(m2·d),透水汽性值由51.3mg·10cm-2·24h-1增大至184.7mg·10cm-2·24h-1;薄膜的拉伸强度减小,断裂伸长率增大.当HBPU用量大于10%时,二者变化幅度不大;AFM图显示:共混膜的表面粗糙度有所增加.共混膜断面SEM图显示:共混膜内部形成了较多的孔隙,有利于水分子的通过.

The synthetic leather PU resin and the hyperbranched polyurethane containing reactive amino（HBPU）were blended in the form of physical distribution.And the blend films were prepared successfully under certain conditions.The effect of hyperbranched polyurethane content on the properties of the films was studied.The results showed that the water absorption rate,water vapor transmission rate and water vapor permeability siginifically improved after adding 10% HBPU,which increased from 0.79% to 2.07%,from 94.314g/（m2·d）to 471.570 2g/（m2·d）and from 51.3mg·10cm-2·24h-1 to 184.7 mg·10cm-2·24h-1,respectively.The tensile strength of membrane decreased,and then the elongation at break increased.While the HBPU content greater than 10%,the changes were not much;AFM showed that the surface roughness of the mixed membranes increased;SEM showed that the blend films formed inside more pore,in favour of water molecules through.