红外热波无损检测用聚乙烯醇复合膜的制备

Preparation of Polyvinyl Alcohol Composite Films Used for Infrared Thermal Wave Nondestructive Detection

采用流延方式制备以聚乙烯醇（PVA）为主要原料，以甘油及淀粉改性的红外热波无损检测外包膜。探究不同的PVA、甘油、淀粉浓度对PVA复合膜力学性能的影响，建立了拟合方程，并利用热重（TGA／DTG）、扫描电子显微镜（SEM）手段对PVA复合膜进行了表征，同时将复合膜应用于红外热波无损检测，进行实际使用性能评价。结果表明，淀粉浓度为0．5g／100mL、甘油浓度为2．0mL／100mL、PVA浓度为25g／100mL时PVA复合膜的综合力学性能达到最佳，拉伸强度为38．02MPa、断裂伸长率为225．60％，其厚度为23μm。TGA／DTG测试结果表明通过淀粉和甘油改性的PVA复合膜在110-200℃质量减少量大于纯PVA膜，氢键在此温度区间断裂；SEM检测可得淀粉、甘油与PVA相容性较好，同时两者的加入也使得膜内部分布更加规则，从而增强了其力学性能；红外热波无损检测试验表明PVA复合膜满足检测要求。

The composite films were prepared by a casting way using polyvinyl alcohol （PVA） as the main raw material, glycerol and starch as the modified material. It can be used in the infrared thermal wave nondestructive. This experiment explored different PVA, glycerol, starch＇s concentrations affected the mechanical properties of PVA composite film. The regression equations was established, and the thermo gravimetric analysis （TGA/DTG）, the scanning electron microscope （SEM） were used to characterize the thermal stability of PVA composite films. At the same time, the composite films were applied in infrared thermal wave nondestructive detection for the performance evaluation of practical use. The results show that： when the starch concentration is 0.5 g/100 mL, glycerol concentration is 2. 0 mL/100 mL, and PVA concentration is 25 g/100 mL, the PVA composite film is the best performance. The thickness of the film is 23μm, the tensile strength is 38.02 MPa and the elongation at break is 225.60%. TGA/ DTG test results show that the starch and glycerol modified PVA composite film at 110 ℃ to 200 ℃ quality reduces weight greater than the pure PVA film, hydrogen bonds fracture in this temperature interval. Infrared thermal wave nondestructive testing experiments show that the PVA composite film meets the test requirements.