Preparation And Properties Of Self-healing Polysiloxane Elastomer Based On Reversible Diels-Alder Reaction

Self-healing materials achieve the purpose of self-detection,self-regulation,and self-repair by sensing changes in environmental factors such as stress,strain,heat,light,electricity,and magnetism.Polysiloxane is one of the most important organosilicon compounds,which may produce various damages during use,resulting in deterioration of material properties and decrease of material life.Based on the Diels-Alder(DA)reaction,a novel polysiloxane elastomer with selfhealing properties was prepared by two-step method and one-step method.In the twostep method,the furan-functionalized polydimethylsiloxane(FAPDMS)was firstly prepared through the amino-epoxy reaction between the epoxy group on furan glycidyl ether(FGE)and the amino group of 3-aminopropyl-terminated polydimethylsiloxane(APDMS);then a kind of polysiloxane elastomer(FAPMDS-BMI)was prepared based on DA reaction between a furan ring on FAPDMS and an imide ring on diphenylmethane bismaleimide(BMI).In the one-step method,FDB embedded with DA bonds was synthesized based on DA reaction between FGE and BMI;then,the polysiloxane elastomer(APDMS-FDB)was obtained by directly crosslinking APDMS with FDB through epoxy-amine reaction.FTIR analysis and swelling experiments demonstrated the successful preparation of FAPDMS-BMI and APDMS-FDB elastomers.Thermal dissolution experiments and DSC analysis indicated that the two kinds of elastomers prepared have dynamic thermoreversible properties.The mechanical test results show that the prepared FAPDMSBMI has excellent resilience and over 90 % self-healing efficiency,but the mechanical property is not ideal,the maximum tensile strength is 0.4 MPa and the elongation at break is about 200 %.And the prepared APDMS-FDB also has excellent resilience and over 70 % self-healing efficiency.Its maximum tensile strength can reach 0.8 MPa,and the elongation at break can be over 400 %.Its highest self-healing efficiency can reach over 90 %.