상세정보

Self-healing and re-processable thermosetting polymers that visualize damage in color are demonstrated. A well-known mechanochromic molecule, spiropyrans (SP) is covalently incorporated in thermo-reversible Diels-Alder (DA) cross-linking networks. Mechanical activation of SPs in DA networks is confirmed by mechanical testing. The damaged areas of the polymers are changing color, emitting fluorescence signals, and completely recovered after heat treatment. Owing to thermo-reversible covalent networks, these polymers can be recycled up to fifteen times without degrading their mechanical, damage-reporting, and self-healing properties. Our autonomic material systems provide a new way to enhance the life span and reliability of thermosetting coatings, which also expands the practical applications of force-induced chemical reactions in a polymer.

1. Introduction	 1
2. Experimental Procedures	 6
2.1. Materials 	6
2.2. Characterization	 6
2.3. Synthesis of mechanically active spiropyran (SP)	 7
2.4. Synthesis of control spiropyran (Ctrl)	 10
2.5. Synthesis of tris(2-maleimidoethyl)amine cross-linkers	  12
2.6. Polymerization of SP-linked poly(LMA-co-FMA) (P) and Ctrl-linked poly(LMA-co-FMA) (C)	 14
2.7. Fabrication of cross-linked polymer using the Diels-Alder reaction (xP and xC)	 14
2.8. Calculation of activation energy	 15
3. Results and Discussion	 16
3.1. SP-linked linear copolymers	 16
3.2. Thermoreversible, SP-linked CANs	 31
3.4. Autonomic damage reporting and self-healing coatings	 35
3.4. Thermomechanical properties/Reprocessability	 41
4. Conclusions	 54

REFERENCES	 55
국문초록	 63
EDUCATION	 64