Synthesis And Properties Of High-performance And Self-healing Thermopiastic Silicone Resin

In this paper,mono functionalized POSS and monofunctionalized NACL were grafted to the side chain of vinyl silicone oil by thiol-ene reaction,respectively,and the large steric effect of the cage-type three-dimensional regular structure of POSS and the hydrogen bonding of NACL were used.The effect realizeed the thermoplasticity and self-healing property of silicone.A series of thermoplastic silicone resins were prepared by adjusting the ratio to obtain products that can be dissolved and melted,which further enriched the synthesis and preparation methods of thermoplastic silicone resins.And its performance was characterized and tested through a series of characterization tests:(1)First,we synthesized a series of vinyl linear polysiloxanes with different molecular weights and different vinyl contents by anionic ring-opening polymerization of tetramethylammonium hydroxide.(2)Through the mercapto-ene click chemical reaction,heptaisobutyl monomercapto POSS was grafted onto the side chain of vinyl silicone oil(PMVS).Due to the caged nanostructure of heptisobutyl POSS,it has huge steric hindrance Effect,reducing the movement capacity of the molecular chain,thereby achieving thermoplasticity and obtaining a thermoplastic silicone resin with high tensile properties.The results show that the mechanical and thermal properties of POSS-based thermoplastic silicone resins are improved with the increase of molecular weight,and the mechanical and thermal properties of POSS-based thermoplastic silicone resins are gradually increased with the increase of molecular weight.(3)Through the mercapto-ene click chemical reaction,the NACL and the C=C double bond of the vinyl silicone oil side chain are subjected to the click chemical reaction to graft the NACL to the side chain of the vinyl polysiloxane.Utilizing the strong hydrogen bonding of NACL to form physical crosslinking points to achieve thermoplastic properties.Because it is the reason for the physical cross-linking point of hydrogen bonding,the material has good self-repairing properties,because hydrogen bonding is a kind of repeating intermolecular bond that can be formed repeatedly.(4)We have successfully synthesized thermoplastic silicone resins through the previous two different effects,and obtained thermoplastic silicone materials with good mechanical properties.Therefore,we combined the two mechanisms to synthesize a third thermoplastic silicone resin.The heptisobutyl monomercapto POSS and NACL were click-grafted to the molecular chain of vinyl polysiloxane according to different ratios,and the huge steric effect of the POSS regular structure and the strong hydrogen bonding of NACL were used,A new type of thermoplastic silicone resin was obtained,and this kind of thermoplastic silicone resin synthesized by multiple functions has received more and more attention.