(495d) Designing Multiple Chemical Functionalities into Adhesive Polymers for Stimulus Responsive and Electronically Conductive Properties

Polymeric adhesives are nonmetallic materials which possess the ability to join two surfaces via chemical and physical bonding. While traditional polymer adhesives function only in the binding of two surfaces, these advanced adhesive polymers must fulfill multiple roles at once. However, it is hard to find a single chemical structure which possesses the multifunctionality required for modern adhesives that work for complex environments. (e.g., strong tissue adhesion and controlled drug delivery) in literature. The talk discusses detailed studies of structure-property relationships for precisely synthesized multifunctional adhesives are rarely found in the literature due to the synthetic challenges. The first type of new functional adhesive polymer is photo-sensitive adhesives. Anthracene forms covalent bonds via 4+4 photocycloaddtion reaction upon exposure to UV light greater than 350 nm. The anthracene was introduced to catechol containing terpolymer to enhance adhesion property. The photocycloaddtion lead crosslinking of the linear terpolymer. The crosslinking results in enhancement of cohesion to improve overall adhesion property. The adhesion strength (J/m2) was enhanced by 850% under UV-irradiation. Another photo-sensitive adhesive is nitrobenzyl containing photocleavable adhesive polymer. This terpolymer is crosslinked by nitrobenzyl groups which can be cleaved under UV irradiation. The loss of the adhesive polymer reduces crosslinking degree (cohesion) in an adhesive polymer matrix. After 30 minutes of UV irradiation the original adhesion strength, 341 kPa, was decreased to 223 kPa, corresponding to a 35% reduction. The adhesion strength continued to decrease to 150 kPa at the 3 hours mark, a 56% reduction. Finally, the talk will discuss heterogeneous metal and carbonic filler free electrically conductive fully organic polymer adhesive poly(N-methacryloyl-3,4-dihydroxyl-L-phenylalanineco-3-sulfopropyl methacrylate):poly(3,4-ethylenedioxythiophene) (PMS:PEDOT). The new conducting adhesive shows high adhesion (1.62 MPa) and conductivity (2.5 S/cm).