形状记忆复合编织圆管的制备及其热致回复性能

为分析编织角、回复温度对形状记忆编织圆管力学性能与形状回复性能的影响,采用改进的双螺杆挤出工艺制备连续碳纤维/形状记忆聚氨酯复合长丝,通过二维编织技术制备得到编织角为15°、30°、45°、60°、75°的圆管,对比分析了其径向支撑力和形状回复率。结果表明:制备的复合长丝中连续碳纤维被形状记忆聚氨酯均匀包覆,且基本位于复合长丝中心位置;编织圆管的径向支撑力与编织角大小成正比关系,编织角为45°时圆管的形状回复率最高,编织角度越接近45°形状回复率越高;回复温度对形状记忆性能有一定的影响,回复温度越高圆管的回复速率越快,形状回复率越大;该圆管结构具有优异的形状回复率,最高可达96%。

Fabrication and thermal-activated recovery properties of shape memory composite braided circular tubes

To investigate the effects of braiding angle and recovery temperature on mechanical properties and shape recovery performances of braided circular tube composites, continuous carbon fiber/shape memory polyurethane composite filament was prepared using the modified twin-screw extrusion technique, and the braided circular tubes with different braiding angles were obtained by 2-D braiding. The braiding angles included 15°, 30°, 45°, 60° and 75°, and the radial strength and shape recovery performances of braided circular tubes were compared. The results show that continuous carbon fiber is evenly coated by shape memory polyurethane and in the center of composite filament. Radial force of the circular tube is proportional to the braiding angle and the closer the braiding angle is to 45°, the higher the shape recovery ratio will be. Recovery temperature has the effect on shape memory properties. As the recovery temperature increases, recovery rate and recovery ratio are both enhanced. The braided circular tube structure demonstrated a shape recovery ratio of up to 96%.