Abstract
The present thesis deals with the synthesis and investigation of new, low-cytotoxic alkyne and thiol monomers and their thiol-yne derived photopolymers. Furthermore, polymerizable photoinitiators featuring low migration in thiol-based resins have been studied. This research is driven by the vision to produce custom-made, biomedical devices by lithography-based additive manufacturing technologies. In the first part of this work alkyne ethers and alkyne carbonates have been explored as low cytotoxic alternatives to the commonly used (meth)acrylates. The work describes the synthesis, the cytotoxic behavior and the characterization of the photoreactivity of alkynes in combination with different thiol monomers. While featuring high reaction rates and also high monomer conversions, investigations on the network properties of cured thiol-yne resins by dynamic thermo-mechanical analysis (DMA), double quantum (DQ) solid state NMR spectroscopy and photorheology have revealed that these monomers show the potential to realize photopolymers with very homogenous network structures, leading to excellent mechanical properties in terms of modulus and polymer toughness. Different stabilizers have been evaluated in the resin that significantly improved the storage stability. It is also shown how the degradation behavior of cured photopolymers can be tuned from hydrolytic susceptibility to hydrolytic stability, dependent on the applied thiol or alkyne monomer. In this context, a new silicone-based thiol has been introduced as non-degradable monomer, which also leads to polymers with reduced water absorption and improved mechanical properties. Printing experiments revealed, that the presented alkyne resins have shown excellent 3D printing behavior with high accuracy as it has been demonstrated on a digital light processing (DLP) based 3D printer. The second part of this work describes the synthesis and characterization of new type I alkyne-functionalized photoinitiators for thiol-ene and thiol-yne resins. It is the aim to realize low photoinitiator migration in biocompatible photopolymers, while still maintaining high initiation performance. Therefore, two different types of photoinitiators have been studied and their overall performances in a biocompatible thiol-ene and thiol-yne resins are discussed intensively. Due to the versatile properties of the presented thiol-yne photopolymers, including low monomer cytotoxicity, high photoreactivity and high monomer conversion together with excellent thermo-mechanical and impact properties, these material shows very high potential for the 3D printing of medical devices.
Translated title of the contribution | Thiol-in Harze für den 3D-Druck biokompatibler Strukturen |
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Original language | English |
Qualification | Dr.mont. |
Supervisors/Advisors |
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Publication status | Published - 2016 |
Bibliographical note
no embargoKeywords
- photopolymerization
- thiol-yne reaction
- 3D printing
- low-cytotoxic
- polymerizable photoinitiators
- alkyne carbonates
- alkyne ethers
- low migration