水性聚氨酯机械发泡涂层的响应面法优化制备

为制备高透湿率和高强度的水性聚氨酯发泡涂层，采用响应面分析法对机械发泡工艺中成膜温度、发泡剂含量和发泡倍率3个参数进行优化。结果表明，回归得到的二次多项式模型显著且失拟项不显著，模型拟合性良好。各因素对透湿率影响顺序为：成膜温度>发泡倍率>发泡剂质量分数；对断裂强度影响顺序为：发泡倍率>成膜温度>发泡剂质量分数。以透湿率和断裂强度最大为原则，得到最优制备工艺条件：成膜温度120°C，发泡剂质量分数为 5.56 %，发泡倍率为 319.17%；在此条件下制备的水性聚氨酯涂层的实际透湿率为6088.71 g/(m2?24h)，断裂强度为1.51 MPa，与模型理论预测值基本相符，表明优化模型有效可靠；以此作为超纤维合成革的发泡层制备水性超细纤维合成革，其透湿率达到 2070.24 g/(m2?24h)，纵向、横向断裂强力分别为161.50、112.38 N。

Preparation of waterborne polyurethane coating by mechanical foaming based onresponse surface methodology

In order to prepare waterborne polyurethane coating with high water vapor transmission rate and tensile strength by mechanical foaming, the factors of coating-forming temperature, foaming agent concentration and foaming ratio in mechanical foaming were optimized by the response surface methodology. The results showed that the regression of the quadratic polynomial model is significant while the lack of fit is not significant,demonstrating thegood fitness of the model. The order of their effects on water vapor transmission rate is coating-forming temperature, foaming ratioandfoaming agent concentration in sequence, while the order of their effects on tensile strength is foaming ratio, coating-forming temperature, andfoaming agent concentration in seqyebce. Based on the maximum value of water vapor transmission rate and the tensile strength the optimum conditions are coating-forming temperature of 120°C, foaming agent concentration of 5.56 % and foaming ratio of 319.17%. Under these conditions, the experimental yields of water vapor transmission rate is 6088.71 g/(m2?24h) andthe tensile strength is1.51 MPa, which are substantially consistent withthe predicted values. Thus,the regression equation is valid and reliable. By taking the waterborne polyurethane coating as the foam layer of microfiber synthetic leather, the water vapor transmission rate is 2070.24 g/(m2?24h) and the perpendicular and lateral tensile forces of the obtained microfiber synthetic leather are 161.50/112.38 N.