Many sticky denizens of the ocean use unique and effective techniques to stick together
and adhere to surfaces underwater. Underwater adhesion is a daunting task that many have set out
to solve. One of the key factors of underwater adhesion and focus of this dissertation will be on
negative charges and their role in underwater adhesion. Following previous work done on
poly[(3,4-dihydroxystyrene)-co-styrene], an adhesive mimic to mussel adhesives, new functional
groups were introduced to the same backbone to determine the change in adhesion in underwater
and dry conditions. These functional groups were mainly comprised of negatively charged
moieties such as sulfonates, phosphates, and phosphonates. Phosphates have been shown to exist
in mussel proteins alongside positively charged proteins.
A main facet of this dissertation will be focused on the specific synthesis pathways of
modified charged synthetic mimics of existing polymer systems both styrene and acrylic based.
Synthetic pathways were a challenging aspect of designing these polymers as functionalization
can add many steps to the synthesis of polymers which makes the process tedious and lengthy.
Characterization of these polymers were also important for determining the successful synthesis
of these functionalized polymers. Several reactions conducted from this research have not been
used on polymeric species and have been shown primarily in small organic molecules. Early work
on poly[(3,4-dihydroxystyrene)-co-styrene]-based sulfonates, phosphates, and phosphonates
established a foundation in pre and post functionalization of polymer species. Testing of adhesion,
exploration of functionalization and synthesis optimization were the main goals for each type of
functionalized polymer.
Following the tests of many poly[(3,4-dihydroxystyrene)-co-styrene] based functionalized
polymers it was shown that acrylic versions of phosphates performed substantially better for both
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dry and underwater adhesion, especially on SAE 304 stainless steel. The acrylic phosphate
polymers were based on previous DMA/MMA polymer systems that have shown to have excellent
adhesive potential. The phosphate monomer MAEP was introduced to the polymer structure,
which facilitated increased binding to steel substrates. Despite the acrylics overwhelmingly higher
adhesion compared to the functionalized poly[(3,4-dihydroxystyrene)-co-styrene] polymers the
phosphonate versions were shown to form a coacervate like material with positive charged
poly[(3,4-dihydroxystyrene)-co-styrene] mimics. These “coacervates” had appreciable adhesion,
much higher than the negative or positive versions had alone in dry conditions but despite this
could not retain their metastable coacervate phase in wet conditions. Further study is underway in
determining the role of negative charges in varying systems and determining whether adding
negative charge to a polymer system truly helps with underwater adhesion alone.
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/12739595 |
| Date | 09 September 2022 |
| Creators | Taylor A Jones (9187493) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/thesis/INTRODUCTION_OF_NEGATIVELY_CHARGED_FUNCTIONALITIES_INTO_DOPA_CONTAINING_POLYMER_MIMICS/12739595 |
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