Synthesis And Application Of Novel Self-healing Microcapsules Containing MMA Monomer

Objective:Self-healing microcapsules with methyl methacrylate(MMA)as self-healing monomer and polyurea formaldehyde(PUF)as shell were synthesized.At the same time,the effect of the content of self-healing microcapsules on the characterization of room-temperature curing denture base resin was investigated,which provided experimental basis for further exploration and expansion of the self-healing technology in the field of dentistry.Method:Part 1:MMA and N,N-dihydroxyethyl-p-toluidine(DHEPT)were chosen as healing agents and PUF as shell to synthesize microcapsules by in situ polymerization.The particle diameter at different stirring rate was observed by optical microscope(OM),the surface morphology was observed by scanning electron microscope(SEM),the chemical composition was analyzed by fourier transform infrared spectroscopy(FTIR),the wrapping rate was analyzed by calculating the content of core material,and the storage stability was analyzed by calculating the content of core material after placement for a certain time.Part 2:These self-healing microcapsules at different mass fraction of 0%(blank control),2.5%,5.0%,7.5%and 10.0%were added into room-temperature curing denture base resin to prepare novel dental self-healing base resin.Three point bending test was used to test the bending strength and elastic modulus of each group(n=10),single edge V-notch beam(SEVNB)specimen was used to test the fracture toughness and self-healing efficiency of each group(n=6),the self-healing performance in water was also tested,and all the results were statistically analyzed.Result:1.OM showed that the particle diameter was different at different stirring rate.SEM showed that the microcapsules were round,dense in shell and rough in surface.FTIR showed that the microcapsules had both the chemical composition of PUF and MMA.At the stirring rate of 600r/min,the content of core material was(79.2±4.1)%and decreased by 2.8%after placement for a certain time.2.When 7.5wt%microcapsules were added into room-temperature curing denture base resin,the bending strength and elastic modulus were(65.95±5.96)MPa and(2.78±1.16)GPa respectively,there was no significant difference between this group and control group(P>0.05).However,when 10wt%microcapsules were added,the bending strength and elastic modulus decreased to(41.30±3.06)MPa and(1.88±0.85)GPa respectively,which was significantly lower than the control group(P<0.05).Adding 7.5wt%and 10.0wt%microcapsules into self-curing base resin,the self-healing efficiency were(62.17±3.71)%and(67.17±3.60)%respectively.The self-healing efficiency of the base resin containing 7.5wt%microcapsules in water was(60.67±5.88)%which had no significant difference from that in moist air(P>0.05).Conclusion:In this study,self-healing microcapsules were synthetized with MMA as the self-healing monomer and PUF as shell material,and then we prepared a novel self-healing room-temperature curing base resin.Adding a certain amount of microcapsules into self-curing denture base resin showed excellent self-healing effect both in moist air and water,which laid a foundation for the application of self-healing materials in the field of dentistry.