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Bicontinuous Materials from Telechelic Macromonomers Using Thiol-ene Chemistry

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dc.contributor.advisorTew, Gregory N.
dc.contributor.advisorHayward, Ryan C.
dc.contributor.advisorTuominen, Mark
dc.contributor.authorWalker, Catherine Nancy
dc.contributor.departmentUniversity of Massachusetts Amherst
dc.date3/27/24 17:21
dc.date.accessioned2024-04-26T16:06:46Z
dc.date.available2024-04-26T16:06:46Z
dc.date.issued2015
dc.date.submittedFebruary
dc.date.submitted2015
dc.description.abstractBicontinuous structures are beneficial to many applications from health and medicine to energy and the environment. Although these materials can be used for many applications, current strategies yield bicontinuous structures only under highly specific processing conditions. Development of a versatile platform to reliably obtain bicontinuous morphologies will be broadly beneficial. This work presents two platforms that can be used to produce bicontinuous morphologies using a simple Mitsunobu/thiol-ene strategy. This platform allows for the incorporation of a variety of polymer chemistries to yield well-defined polymer networks or multiblock copolymers (MBCs). It also allows for the systematic investigation of factors affecting the morphology such as the molecular weight between cross-links and the volume fraction of the network components. The ease at which these variables can be systematically investigated allows for rigorous fundamental studies of these composite systems. In the first co-network system, the platform’s ability to tailor mechanical properties while maintaining good ion conductivity was demonstrated by comparing PEG-PDMS co-networks to PEG networks using EIS and DMA. Also, the effect of salt loading on thermal properties was explored using DSC. The second system, PEG-PS co-networks, demonstrated that varying the molecular weight of the precursor polymers results in control over d-spacing that fits well to de Gennes’s prediction (d ~ Mn0.5). Despite the variation in d-spacing, 22 - 55 nm, the ion conductivity and mechanical properties remained relatively consistent, demonstrating versatility in this system. Critical percolation thresholds were investigated by using ion conductivity and storage modulus to probe the continuity of the PEG and PS phases, respectively. Percolation theory suggests this system has a wide bicontinuous compositional window from fPEG = 0.225 -0.675. A preliminary phase diagram was generated by combining results from the molecular weight and volume fraction series. Finally, a simple synthesis for (MBCs) is demonstrated using the same Mitsunobu/thiol-ene platform. MBCs with ~4 blocks and two or three types of macromonomers were synthesized. Disordered phase separation was shown by SAXS and AFM. The versatile Mitsunobu/thiol-ene platform is easily able to synthesize different architectures using a range of polymer chemistries for various morphology and property studies.
dc.description.degreeDoctor of Philosophy (PhD)
dc.description.departmentPolymer Science and Engineering
dc.identifier.doihttps://doi.org/10.7275/6250944.0
dc.identifier.orcidN/A
dc.identifier.urihttps://hdl.handle.net/20.500.14394/19533
dc.relation.urlhttps://scholarworks.umass.edu/cgi/viewcontent.cgi?article=1304&context=dissertations_2&unstamped=1
dc.source.statuspublished
dc.subjectPolymer Science
dc.titleBicontinuous Materials from Telechelic Macromonomers Using Thiol-ene Chemistry
dc.typeopenaccess
dc.typedissertation
digcom.contributor.authorisAuthorOfPublication|email:cnwalker@polysci.umass.edu|institution:University of Massachusetts Amherst|Walker, Catherine Nancy
digcom.identifierdissertations_2/331
digcom.identifier.contextkey6250944
digcom.identifier.submissionpathdissertations_2/331
dspace.entity.typePublication
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