CO_(2)激光对聚酰亚胺织物的表面改性研究

Study on surface modification of polyimide fabrics by CO_(2) laser

采用波长为10.6μm的CO_(2)激光对聚酰亚胺织物进行表面改性。通过单因素试验优化激光改性工艺参数,测试改性后织物滴水扩散时间、接触角和抗弯刚度,分析CO_(2)激光改性聚酰亚胺织物的作用机制,探讨激光改性对聚酰亚胺织物颜色参数、表面形貌、分子结构及结晶度的影响。结果表明:激光改性能够改善聚酰亚胺织物的亲水性,随着激光功率的增加及扫描速度、激光步距的减小,改性聚酰亚胺织物的滴水扩散时间和接触角呈下降趋势,亲水性提升;优化的激光改性工艺参数为激光功率20 W、扫描速度200 mm/s、激光步距0.2 mm,此时激光能量密度为40 J/cm 2;激光的光热作用造成聚酰亚胺大分子链断裂并在分子链中引入羟基等极性基团,以及激光产生的刻蚀造成织物表面粗糙度增加,是织物亲水性提高的主要原因;CO_(2)激光改性后聚酰亚胺织物的颜色参数基本不变,结晶度和断裂强力下降。

The surface of polyimide fabrics was modified by CO_(2)laser with wavelength of 10.6μm.The CO_(2)laser modification process was parameters were optimized by single factor experiment,and the changes of drip diffusion time,contact angle and bending stiffness of the modified fabrics were tested.The mechanism of CO_(2)laser modified polyimide fabrics was analyzed,and the effects of laser modification on the color parameters,surface morphology,molecular structure and crystallinity of polyimide fabrics were discussed.The results show that laser modification can improve the hydrophilicity of polyimide fabrics.With the increase of laser power and the decrease of scanning speed and laser step distance,the drip diffusion time and contact angle of modified polyimide fabrics decrease,and the hydrophilicity increases.The optimized laser modification parameters are as follows:laser power of 20 W,scanning speed of 200 mm/s,and laser step distance of 0.2 mm.In this case,the laser energy density is 40 J/cm 2.The main reasons for the improvement of the hydrophilicity of modified polyimide fabrics are the break of the polyimide macromolecular chain caused by the photothermal effect of the laser and the introduction of polar groups such as hydroxyl group into the molecular chain,as well as the increase of the surface roughness of the fabric caused by laser etching.After CO_(2)laser modification,the color parameters of the polyimide fabrics are basically unchanged,but the crystallinity decreases and the breaking strength decreases.