聚醚型热塑性聚氨酯薄膜的真空干燥特性研究  

Study on the Vacuum Drying Characteristics of Polyether Thermoplastic Polyurethane Film

作　　者：胡恩源 阎格 蔡利海 朱孟府 邵伟光 HU Enyuan;YAN Ge;CAI Lihai;ZHU Mengfu;SHAO Weiguang(Institute of Systems Engineering,Academy of Military Sciences,Beijing 100071,China)

机构地区：[1]军事科学院系统工程研究院,北京100071

出　　处：《真空科学与技术学报》2023年第2期104-111,共8页Chinese Journal of Vacuum Science and Technology

摘　　要：采用模压成型工艺将聚醚型热塑性聚氨酯粒料压制成膜,研究了温度对TPU薄膜真空干燥特性的影响,计算了干燥过程中的有效扩散系数和扩散活化能,选取了5种干燥动力学模型进行拟合分析,并考察了不同温度干燥前后TPU薄膜力学性能的变化。结果表明:真空干燥温度越高,干燥速率越快,干燥时间越短,同时,TPU薄膜的干燥过程主要发生在降速阶段。两相扩散方程能够很好的反映TPU薄膜真空干燥过程中的水分比变化规律,计算得出其有效水分扩散系数为2.26×10^(-10)-7.28×10^(-10)m^(2)/s,扩散活化能为37.49 kJ/mol。此外,聚醚型TPU薄膜的断裂伸长率几乎不因吸水和干燥过程发生变化,而60℃以下的真空干燥可使其因吸水而降低的拉伸强度得到明显恢复。The polyether thermoplastic polyurethane pellets were pressed into films by a compression molding process.The effect of temperature on the vacuum drying characteristics of TPU films was studied,and the effective diffusion coefficient and diffusion activation energy during the drying process were calculated.Five drying kinetic models were selected to fit and analyze the vacuum drying process of TPU films,and the mechanical properties of TPU films before and after drying at different temperatures were investigated.The results showed that in the vacuum drying process of TPU films,increasing the drying temperature would speed up the drying rate and shorten the drying time,and the drying process of the TPU films mainly occurred in the deceleration stage.The two-phase diffusion equation well reflected the change law of the moisture ratio in the vacuum drying process of the TPU films.The effective moisture diffusion coefficient was calculated to be 2.26×10^(-10)-7.28×10^(-10)m^(2)/s,and the diffusion activation energy was 37.49 kJ/mol.In addition,the elongation at break of the polyether TPU films hardly changed due to water absorption and drying process,and vacuum drying below 60℃ significantly recovered the tensile strength reduced by water absorption.

关 键 词：热塑性聚氨酯 真空干燥 数学模型 薄层干燥 力学性能 

分 类 号：TB324[一般工业技术—材料科学与工程] TQ334.9[化学工程—橡胶工业]