A self-healing particulate composite reinforced with strain hardened short shape memory polymer fibers

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• 作者：Guoqiang Li ; Pengfei Zhang
• 关键词：Self-healing ; Shape memory polymer fiber ; Short fiber reinforced composite
• 刊名：Polymer
• 出版年：2013
• 出版时间：16 August, 2013
• 年：2013
• 卷：54
• 期：18
• 页码：5075-5086
• 全文大小：3432 K

文摘

A particulate composite dispersed with thermoplastic particles and strain hardened short shape memory polymer fibers was prepared to evaluate its ability to repeatedly heal wide-opened cracks per the two-step close-then-heal (CTH) self-healing scheme. A two-step coating approach was used to enhance the shape fixity and workability of the cold-drawn programmed short polyurethane fibers. The relationship between recovery-stress and recovery-strain was experimentally determined by partially constrained shape recovery test. Notched beam specimens were prepared and fracture-healing was conducted up to five cycles. It is found that the composite was able to heal the wide-opened crack repeatedly with considerable healing efficiency. It is also found that the healing efficiency increases as the fiber length increases, but in a reduced increasing rate. The recovery stress-recovery strain of the strain hardened shape memory polymer fiber behaves nonlinearly. The coated fiber is more effective than the uncoated fiber in closing wide-opened cracks when the recovery strain is within a certain range.