Abstract
ObjectiveFillers are widely utilized to enhance the mechanical properties of polymer resins. However, polymerization stress has the potential to increase due to the higher elastic modulus achieved upon filler addition. Here, we demonstrate a hyperbranched oligomer functionalized glass filler UV curable resin composite which is able to reduce the shrinkage stress without sacrificing mechanical properties. MethodsA 16-functional alkene-terminated hyperbranched oligomer is synthesized by thiol-acrylate and thiol-yne reactions and the product structure is analyzed by 1H NMR, mass spectroscopy, and gel permeation chromatography. Surface functionalization of the glass filler is measured by thermogravimetric analysis. Reaction kinetics, mechanical properties and shrinkage stress are studied via Fourier transform infrared spectroscopy, dynamic mechanical analysis and a tensometer, respectively. ResultsSilica nanoparticles are functionalized with a flexible 16-functional alkene-terminated hyperbranched oligomer which is synthesized by multistage thiol-ene/yne reactions. 93% of the particle surface was covered by this oligomer and an interfacial layer ranging from 0.7nm to 4.5nm thickness is generated. A composite system with these functionalized silica nanoparticles incorporated into the thiol–yne–methacrylate resin demonstrates 30% reduction of shrinkage stress (from 0.9MPa to 0.6MPa) without sacrificing the modulus (3100±300MPa) or glass transition temperature (62±3°C). Moreover, the shrinkage stress of the composite system builds up at much later stages of the polymerization as compared to the control system. SignificanceDue to the capability of reducing shrinkage stress without sacrificing mechanical properties, this composite system will be a great candidate for dental composite applications.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.