Adhesive Polymer Research Articles

Electroactive covalent linkers for enhancing conducting polymer adhesion, charge transfer, and biological integration of PEDOT-coated carbon microfibers

Poly(3,4-ethylenedioxythiophene) (PEDOT)-coated carbon microfibers (PCMFs) are a key technology for developing advanced neuroprosthetic electrodes and electroactive tissue scaffolds. However, for their successful application in human therapeutics, PEDOT adhesion to the carbon substrate must be enhanced without compromising electric charge transfer. Here, electrically functional linkers are synthesized to modify the surface at the nanoscale, facilitating the covalent bonding of EDOT to carbon. The properties of the resulting microfibers are compared before and after PEDOT polymerization. PCMFs deterioration is studied by applying controlled mechanical stress in vitro or by implanting them in the rodent spinal cord in vivo. Amino phenyl-EDOT derivatives allow for efficient covalent carbon surface functionalization and PEDOT electropolymerization but substantially reduce charge transfer as assessed by chronopotentiometry, electrochemical impedance spectroscopy, and cyclic voltammetry. Nevertheless, the azido-EDOT (EDOT-Ph-N3) derivative is similarly effective for carbon surface modification, enabling PEDOT polymerization to develop a nanostructured CMF surface based on robust covalent bonds, and enhancing both electric charge transfer and PEDOT adhesion to the carbon substrate. This makes PCMFs more resistant to polymer delamination when assessed in vitro or when implanted into the neural tissue. Azido-EDOT modified PCMFs also show excellent biological integration within the spinal cord, causing negligible tissue damage and cell reactivity. Overall, azido-EDOT provides a superior electroconducting linker for anchoring PEDOT and optimizes the electrical, mechanical, and biological performance of PCMFs.

Investigation of the Mechanical Properties of Reinforced Calcareous Sand Using a Permeable Polyurethane Polymer Adhesive.

Calcareous sand has been widely used as a construction material for offshore projects; however, the problem of foundation settlement caused by particle crushing cannot be ignored. Although many methods for reinforcing calcareous sands have been proposed, they are difficult to apply on-site. In this study, a permeable polyurethane polymer adhesive (PPA) was used to reinforce calcareous sands, and its mechanical properties after reinforcement were investigated through compression creep, direct shear, and triaxial shear tests. The reinforcement mechanism was analyzed using optical microscopy, CT tomography, and mercury intrusion porosimetry. The experimental results indicate that there is a critical time during the compression creep process. Once the critical time is surpassed, creep accelerates again, causing failure of the traditional Burgers and Murayama models. The direct shear strength of the fiber- and geogrid-reinforced calcareous sand reinforced by PPA was approximately nine times greater than that without PPA. The influence of normal stress was not significant when the moisture content was less than 10%, but when the moisture content was more than 10%, the shear strength increased with an increase in vertical normal stress. Strain-softening features can be observed in triaxial shear tests under conditions of low confining pressure, and the relationship between the deviatoric stress and strain can be described using the Duncan-Chang model before softening occurs. The moisture content also has a significant influence on the peak strength and cohesive force but has little influence on the internal friction angle and Poisson's ratio. This influence is caused by the different PPA structures among the particles. The higher the moisture content, the greater the number of pores left after grouting PPA.

Application of polymer adhesive hydrogel in wound healing

As the global adhesive industry continues to grow, researchers are discovering that polymer adhesives are playing an increasing role in the medical field, polymer adhesives have attracted more and more attention from the medical industry due to their unique advantages, such as hydrogels, have gradually appeared, which can effectively help wound healing. Most of the hydrogels have good biocompatibility and water absorption, and have the advantages of controllable structure, adjustable performance and easy degradation. Compared with traditional wound healing methods, hydrogels effectively reduce additional trauma and leakage and allow for greater tissue integration. This paper reviews the types of polymeric adhesive hydrogels and examples of some of them being artificially modified to be applied to the field of wound healing. Analyzes their mechanism of action and the advantages and shortcomings of their clinical applications, and finally looks into the potential functions and clinical efficacy of hydrogels in the future.

Electrical Tissue Adhesives for Strain‐Insensitive In‐situ Biosensing

In‐situ biosensing, a rapidly evolving field that focuses on the development of biosensors capable of on‐site detection of biomolecules directly from local tissue regions, holds the potential to revolutionize medicine through real‐time monitoring, personalized diagnosis, and targeted therapies. However, interfacing rigid, nonstretchable biosensors with soft, deformable tissues presents significant challenges due to their fundamentally contradictory properties. Herein, an electrical tissue adhesive featuring an entangled adhesive polymer network interpenetrated with a sacrificial dissipative polymer network is developed, which can rapidly and robustly adhere electrochemical biosensors with biological tissues, enabling strain‐insensitive physiological monitoring. The electrical tissue adhesive achieves a high fracture toughness of up to 3000 J m−2, a low Young's modulus of around 20 kPa, superior stretchability up to 15 times its initial length, and an overall biosensor‐tissue interfacial toughness of up to 500 J m−2. Using an electrochemical glucose sensor as one example, it is demonstrated that the electrical tissue adhesive can maintain resilient glucose sensing under various stress states and stretch levels. Additionally, the application of the electrical tissue adhesive for in‐situ monitoring of exercise and diet in subjects with various BMIs is demonstrated by measuring glucose concentration in sweat.

Robust and Reversible Thermal/Electro‐Responsive Supramolecular Polymeric Adhesives via Synergistic Hydrogen‐Bonds and Ionic Junctions

Adhesive conducting elastomers are rising materials towards cutting‐edge applications in wearable and implantable soft electronics. Yet, engineering the conductive adhesives with robust and tunable interfacial bonding strength is still in its infancy stage. We herein identify a structurally novel supramolecular polymer scaffold, characterized by synergistic coexistence of hydrogen‐bonding (H‐bonding) interactions and electrostatic ionic junctions, endowing the robust and tunable elastic conducting adhesives with remarkable thermal/electro‐responsive performance. H‐bonding association and electrostatic interaction play orthogonal yet synergistic roles in the strong supramolecular adhesive formation, serving as the leveraging forces for opposing both cohesion and adhesion energy. To do so, six‐arm star‐shaped random copolymers P(DAP‐co‐Thy‐co‐MBT)6 are strategically designed, bearing H‐bonding PDAP (poly(diaminopyridine acrylamide)) and PThy (poly(thymine)) segments, which can form hetero‐complementary DAP/Thy H‐bonding association, along with conductive poly(ionic liquid)s segment: PMBT, (poly(1‐[2‐methacryloylethyl]‐3‐methylimidazolium bis(trifluoromethane)‐sulfonamide)). DAP/Thy H‐bonding association, along with electrostatic ionic interaction, can yield dual supramolecular forces crosslinked polymeric networks with robust cohesion energy. Moreover, coexistence of poly(ionic liquid)s can impact and interfere the configuration of H‐bonding association, liberate more free DAP and Thy motifs to form H‐bonds towards substrate, affording strong surface adhesion in a synergistic manner. This work demonstrates a significant forward step towards potential adhesives devoted to hybrid electronic devices.

Bacterial Binding to Polydopamine-Coated Magnetic Nanoparticles.

In medical infections such as blood sepsis and in food quality control, fast and accurate bacteria analysis is required. Using magnetic nanoparticles (MNPs) for bacterial capture and concentration is very promising for rapid analysis. When MNPs are functionalized with the proper surface chemistry, they have the ability to bind to bacteria and aid in the removal and concentration of bacteria from a sample for further analysis. This study introduces a novel approach for bacterial concentration using polydopamine (pDA), a highly adhesive polymer often purported to create antibacterial and antibiofouling coatings on medical devices. Although pDA has been generally studied for its ability to coat surfaces and reduce biofilm growth, we have found that when coated on magnetic nanoclusters (MNCs), more specifically iron oxide nanoclusters, it effectively binds to and can remove from suspension some types of bacteria. This study investigated the binding of pDA-coated MNCs (pDA-MNCs) to various Gram-negative and Gram-positive bacteria, including Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and several E. coli strains. MNCs were successfully coated with pDA, and these functionalized MNCs bound a wide variety of bacterial strains. The efficiency of removing bacteria from a suspension can range from 0.99 for S. aureus to 0.01 for an E. coli strain. Such strong capture and differential capture have important applications in collecting bacteria from dilute samples found in medical diagnostics, food and water quality monitoring, and other industries.

Metal-phenolic network composites: from fundamentals to applications.

Composites with tailored compositions and functions have attracted widespread scientific and industrial interest. Metal-phenolic networks (MPNs), which are composed of phenolic ligands and metal ions, are amorphous adhesive coordination polymers that have been combined with various functional components to create composites with potential in chemistry, biology, and materials science. This review aims to provide a comprehensive summary of both fundamental knowledge and advancements in the field of MPN composites. The advantages of amorphous MPNs, over crystalline metal-organic frameworks, for fabricating composites are highlighted, including their mild synthesis, diverse interactions, and numerous intrinsic functionalities. The formation mechanisms and state-of-the-art synthesis strategies of MPN composites are summarized to guide their rational design. Subsequently, a detailed overview of the chemical interactions and structure-property relationships of composites based on different functional components (e.g., small molecules, polymers, biomacromolecules) is provided. Finally, perspectives are offered on the current challenges and future directions of MPN composites. This tutorial review is expected to serve as a fundamental guide for researchers in the field of metal-organic materials and to provide insights and avenues to enhance the performance of existing functional materials in applications across diverse fields.

Thermally-responsive dismantlable adhesion system for steel plates using methacrylate copolymers containing a tert-butoxycarbonyl group

A drastic change in the bulk properties of adhesive materials as well as a reduction of interfacial interaction is an important key for the development of dismantlable adhesion systems, i.e., reliable bonding systems with a function of on-demand debonding. The deprotection of tert-butoxycarbonyloxy (BOC) groups included in adhesive polymers can be applied to the construction of a dismantlable adhesion system for steel plates combined with acrylic and epoxy adhesives. In this study, we evaluated the adhesive properties of the copolymers of 2-(tert-butoxycarbonyloxy)ethyl methacrylate (BHEMA), glycidyl methacrylate (GMA), and 3-trimethoxysilylpropyl methacrylate (SMA) for the dismantlable bonding of steel plate cold commercial (SPCC). Spontaneous dismantling of the SPCC adhesive structures was achieved after heat treatment under the conditions at 210 °C for 15 min when the BHEMA/GMA/SMA copolymers with an appropriate copolymer composition were used as the acrylic adhesives or the primers for epoxy adhesion. We discuss the interfacial interactions between the adherend and the adhesives for reliable adhesion and the effects of the deprotection of the BOC groups for dismantling to exhibit both an adhesion strength required for metal bonding and a rapid decrease in the strength by thermal stimulus.

Polyester Adhesives via One-Pot, One-Step Copolymerization of Cyclic Anhydride, Epoxide, and Lactide.

Polyesters (PEs) are sustainable alternatives for conventional polymers owing to their potential degradability, recyclability, and the wide availability of bio-based monomers for their synthesis. Herein, we used a one-pot, one-step self-switchable polymerization linking the ring-opening alternating copolymerization (ROAC) of epoxides/cyclic anhydrides with the ring-opening polymerization (ROP) of L-lactide (LLA) to synthesize PE-based hot-melt adhesives with a high bio-based content. In the cesium pivalate-catalyzed self-switchable polymerization of glutaric anhydride (GA), butylene oxide (BO), and LLA using a diol initiator, the ROAC of GA and BO proceeded whereas the ROP of LLA simultaneously proceeded very slowly, resulting in a copolyester consisting of poly(GA-alt-BO) and poly(L-lactide) (PLLA) segments with tapered regions, that is, PLLA-tapered block-poly(GA-alt-BO)-tapered block-PLLA (PLLA-tb-poly(GA-alt-BO)-tb-PLLA). Additionally, a series of tapered-block or real-block copolyesters consisting of poly(anhydride-alt-epoxide) (A segment) and PLLA (B segment) with AB-, BAB-, (AB)3-, and (AB)4-type architectures of different compositions and molecular weights were synthesized by varying the monomer combinations, alcohol initiators, and initial feed ratios. The lap shear tests of these copolyesters revealed an excellent relationship between the adhesive strength and polymer structural parameters. The (AB)4-type star-block copolyester (poly(GA-alt-BO)-tb-PLLA)4 exhibited the best adhesive strength (6.74 ± 0.64 MPa), comparable to that of commercial products, such as PE-based and poly(vinyl acetate)-based hot-melt adhesives.

Structurally-colored adhesives for sensitive, high-resolution, and non-invasive adhesion self-monitoring

Polymeric adhesives are critical in many applications, from daily life to implantable devices and soft robotics. Monitoring adhesion in a real-time and convenient manner before premature failure is essential yet challenging. Herein, we present structurally-colored adhesives for sensitive, high-resolution, and non-invasive adhesion self-monitoring via distinct color change for detecting subtle deformation and debonding. The structurally-colored adhesives are designed by integrating one-dimensional photonic nanochains into exemplified acrylate-copolymer-based adhesives and demonstrate distinct color-changing capability through a unique tilting mechanism of nanochains under shear. Our structurally-colored adhesives can be customized as pressure-sensitive and structural adhesives, exhibiting ultrafast response (<60 ms), high sensitivity, and high resolution (~120 μm). Moreover, predicting adhesion states and premature failure can be achieved assisted by imaging systems and machine learning algorithms with an average accuracy of up to 97.2%. Our structurally-colored adhesives are expected to offer a practical paradigm for structural health monitoring in the Internet of Things era.

Optimization In-vitro Evaluation and Scratch Wound Healing Assay of Hexacosane Topical Gel for Wound Healing.

The compounds hexocosane, a sterol hydrocarbon identified in the dichloromethane extract and isolated from marine sponges of the genus Agelas. Hexocosane possesses anti-inflammatory and antioxidant activities that reduce inflammation and oxidative stress, they promote cell proliferation and angiogenesis, facilitating tissue regeneration and repair. This multifaceted approach makes this secondary metabolite a promising candidate for developing advanced wound care therapies that effectively address both infection control and wound healing. On the basis of viscosity, in-vitro release, and skin retention, optimal gel formulations were developed with hexocosane (1%) to achieve the best results. A response surface methodology Box-Behnken design was applied on three factors and three levels [carbopol 940 (1, 1.25 and 1.5%), hydroxypropyl methylcellulose (HPMC) (1,1.5 and 1.2%), and propylene glycol (0–1–1.5% and 1–2%, respectively] using three factors and three levels. In order to assess the spreadability and viscosity, a glass slide and a Brookfield viscometer were used. An assay was conducted to determine how topical gel affects wound healing. The optimization study of the gel formulation, involving variations in adhesive polymer (Carbopol 940), release retarding polymer (HPMC K4M), and penetration enhancer (Surfactant), has identified three noteworthy formulations (F4, F8 &amp; F14). Each formulation is characterized by specific attributes such as viscosity, in-vitro drug release, and skin retention. All samples were found to elicit significant wound healing efficacy as evidenced from the representative photomicrographs. The maximum efficacy was elicited by formulation (F4) with 100 mg drug at the time duration of 36 hours.

Numerical Investigation of Fracture Behaviour of Polyurethane Adhesives under the Influence of Moisture.

The mechanical behaviour of polymer adhesives is influenced by the environmental conditions leading to ageing and affecting the integrity of the material. The polymer adhesives have hygroscopic behaviour and tend to absorb moisture from the environment, causing the material to swell without applying external load. The focus of the work is to investigate the viscoelastic material behaviour under ageing conditions. The constitutive equations and the governing equations to numerically investigate the fracture in swollen viscoelastic material are discussed to describe the numerical implementation. Phase-field damage modelling has been used in numerical studies of ductile and brittle materials for a long time. The finite-strain phase-field damage model is used to investigate the fracture behaviour in aged viscoelastic polymer adhesives. The finite-strain viscoelastic model is formulated based on the continuum rheological model by combining spring and Maxwell elements in parallel. Commercially available post-cured crosslinked polyurethane adhesives are used in the current investigation. Post-cured samples of crosslinked polyurethane adhesives are prepared for different humidity conditions under isothermal conditions. These aged samples are used to perform tensile and tear tests and the test data are used to identify the material parameters from the curve fitting process. The experiment and simulation are compared to relate the findings and are the first step forward to improve the method to model crosslinked polymers.

Bioinspired Asymmetric-Adhesion Janus Hydrogel Patch Regulating by Zwitterionic Polymers for Wet Tissues Adhesion and Postoperative Adhesion Prevention.

Asymmetrically adhesive hydrogel patch with robust wet tissue adhesion simultaneously anti-postoperative adhesion is essential for clinical applications in internal soft-tissue repair and postoperative anti-adhesion. Herein, inspired by the lubricative role of serosa and the underwater adhesion mechanism of mussels, an asymmetrically adhesive hydrogel Janus patch is developed with adhesion layer (AL) and anti-adhesion layer (anti-AL) through an in situ step-by-step polymerization process in the mold. The AL exhibits excellent adhesion to internal soft-tissues. In contrast, the anti-AL demonstrated ultralow fouling property against protein and fibroblasts, which hinders the early and advanced stages of development of the adhesion. Moreover, the Janus patch simultaneously promotes tissue regeneration via ROS clearance capability of catechol moieties in the AL. Results from in vivo experiments with rabbits and rats demonstrate that the AL strongly adheres to traumatized tissue, while the anti-AL surface demonstrate efficacy in preventing of post-abdominal surgery adhesions in contrast to clinical patches. Considering the advantages in terms of therapeutic efficacy and off the shelf, the Janus patch developed in this work presents a promise for preventing postoperative adhesions and promoting regeneration of internal tissue defects.

Crosslinking reactions of a model aminated lignin compound as a platform for building thermosetting polymers for lignin-based bio adhesives

As millions of tons of kraft lignin are being wasted, a potential application is to use its crosslinking reactions to build thermosetting bio adhesives. However, the crosslinking reactions between lignin molecules are not fully understood. The present study aims to elucidate the crosslinking reactions of the model lignin compound guaiacylglycerol-β-guaiacyl ether (GGE) via one-step hydroxymethylation/ amination with formaldehyde and diethylenetriamine (DETAM), or one-step glyoxylation/ amination with glyoxal and DETAM via liquid NMR techniques such as 1H NMR, 13C NMR, 2D 1H–13C, and 1H–15N HSQC NMR. Specifically, the 2D 1H–13C HSQC NMR spectra confirm the presence of –CH2–NH– with a chemical shift of 1H 2.6–3.6/13C 40–60 ppm, and the formation of methylene linkages via the crosslinking reaction. Also, the 2D 1H–15N HSQC NMR spectra clearly detect the formation of amide and imine bonds at 1H 7.8/15N 110 and 1H 8.07/15N 121.5 ppm from the crosslinked GGE.

Multifunctional Photothermal Nanorods for Targeted Treatment of Drug-Resistant Bacteria-Induced Wound Healing.

The challenge of drug-resistant bacteria-induced wound healing in clinical and public healthcare settings is significant due to the negative impacts on surrounding tissues and difficulties in monitoring the healing progress. We developed photothermal antibacterial nanorods (AuNRs-PU) with the aim of selectively targeting and combating drug-resistant Pseudomonas aeruginosa (P. aeruginosa). The AuNRs-PU were engineered with a bacterial-specific targeting polypeptide (UBI29-41) and a bacterial adhesive carbohydrate polymer composed of galactose and phenylboronic acid. The objective was to facilitate sutureless wound closure by specially distinguishing between bacteria and nontarget cells and subsequently employing photothermal methods to eradicate the bacteria. AuNRs-PU demonstrated high photothermal conversion efficiency in 808 nm laser and effectively caused physical harm to drug-resistant P. aeruginosa. By integrating the multifunctional bacterial targeting copolymer onto AuNRs, AuNRs-PU showed rapid and efficient bacterial targeting and aggregation in the presence of bacteria and cells, consequently shielding cells from bacterial harm. In a diabetic rat wound model, AuNRs-PU played a crucial role in enhancing healing by markedly decreasing inflammation and expediting epidermis formation, collagen deposition, and neovascularization levels. Consequently, the multifunctional photothermal therapy shows promise in addressing the complexities associated with managing drug-resistant infected wound healing.

Polymer coating by oxidative polymerization of a new dopamine analogue with two amino groups

In our quest to expand the comprehensive chemistry of polydopamine and its catechol-containing analogous adhesive polymers we developed a new monomer, specifically 4-[3-amino-2-(aminomethyl)propyl]benzene-1,2-diol ADA. This compound is an analogue of dopamine characterized by an elongated and branched alkyl side chain that incorporates two amino groups. ADA was synthesized in two steps from 3,4-dihydroxybenzaldehyde in high yields. Exposure to air in aqueous Tris solution initiated polymerization leading to a dark colored product PADA that can adhere to surfaces forming continuous layers. The product was analyzed by FTIR, NMR, UV–vis-spectroscopy, AFM, HR-ESI-MS spectrometry, XPS, DPV, DLS and contact angle measurement. Based on these analyses, a general structure of the product is proposed as along with a mechanism of its formation. Notably, the properties of PADA are distinct from those of polydopamine offering different potential application. In particular, the additional amino groups could be used for interesting linkage of other functional moieties.

Investigating the impact of water capillary forces on polymer‐substrate adhesion using force spectroscopy

AbstractAtomic force microscopy (AFM) was used to characterize how water capillary forces impact polymer‐substrate adhesion in ambient conditions. We analyzed hydrophobic poly(styrene‐co‐butadiene) interacting with mica, silicon, and graphite substrates, each with distinct surface properties. Using polymer‐coated AFM tips/blank substrates, and vice versa, we explored the roles of water capillary forces and polymer‐substrate interactions on adhesion. When force spectroscopy experiments were conducted using polymer‐coated tips, adhesion was the largest on mica due to substantial water capillary forces between the tip and hydrophilic substrate. However, when using a blank tip and polymer‐coated substrates, the adhesion was largest on graphite and smallest on mica. This is because the blank tip interacted with the same hydrophobic polymer film for each experiment; therefore, water capillary forces had an equal magnitude on each substrate, allowing polymer‐substrate interactions to be compared even within ambient conditions. Moreover, single‐chain desorption events were consistently observed in these force‐distance curves since water capillary forces were significantly reduced. This study elucidated several aspects of how water capillary forces impact polymer‐substrate adhesion, which benefits applications reliant on polymer adhesion in ambient conditions and contributes to the fundamental understanding of polymer interface interactions.

Adhesion Evolution: Designing Smart Polymeric Adhesive Systems with On-Demand Reversible Switchability.

Smart polymeric switchable adhesives represent a rapidly emerging class of advanced materials, exhibiting the ability to undergo on-demand transitioning between "On" and "Off" adhesion states. By selectively tuning external stimuli triggers (including temperature, light, electricity, magnetism, and chemical agents), we can engineer these materials to undergo reversible changes in their bonding capabilities. The strategic design selection of stimuli is a pivotal factor in the design of switchable adhesive systems. This review outlines recent advancements in the field of smart switchable polymeric adhesives over the past decade with a focus on the selection of stimulus triggers. These systems are further categorized into one of four adhesion switching mechanisms upon initiation by a specific stimuli-trigger: (i) interfacial adhesion, (ii) stiffness, (iii) contact area, or (iv) suction-based switching. Evaluation of adhesion switching performance across systems is primarily made based on three key metrics: (i) maximum adhesion strength, (ii) switch ratio, and (iii) switch time. Different stimuli and mechanisms offer distinct advantages and limitations, influencing the performance characteristics and applicability of these materials across domains such as detachable biomedical devices, robotic grippers, and climbing robots. This review thus offers a perspective on the present advancements and challenges in this emerging field, along with insights into future directions.

Viscoelastic-adhesive modeling of hybrid adhesively bonded double-lap joints: analytical and numerical studies

ABSTRACT There are a limited number of studies examining the viscoelastic and viscoplastic behavior of adhesive joints. If there is more than one adhesive in the overlap region, the problem becomes more complex and viscoelastic modeling of the overlap region becomes difficult. There is no study in the literature that covers such a bonding (overlap) scheme and examines the viscoelastic behavior of the double lap joint (DLJ). In this study, the effect of viscoelasticity of polymeric adhesives on shear stress and strain distributions in the hybrid-adhesive layer of a DLJ is studied. Maxwell-Wiechert (MW) viscoelastic material model is used to define the viscoelastic behavior of the adhesives. Analytical and finite element (FE) results are compared for both mono- and hybrid-adhesive joints under the step load. Good matches are observed between the analytical and numerical results. Four different hybrid-adhesive joints with different combinations of the adherend thicknesses are investigated by considering only the analytical method. In order to investigate the effect of the loading type on the viscoelastic behavior, step and ramp loads were applied to the joint separately. It is observed that applying the ramp load to the hybrid-adhesive joints affects the shear stresses occurred at the ends of the overlap more than the mono-adhesive joints.

Recyclable surgical, consumer, and industrial adhesives of poly(α-lipoic acid).

Polymer adhesives play an important role in many medical, consumer, and industrial products. Polymers of α-lipoic acid (αLA) have the potential to fulfill the need for versatile and environmentally friendly adhesives, but their performance is plagued by spontaneous depolymerization. We report a family of stabilized αLA polymer adhesives that can be tailored for a variety of medical or nonmedical uses and sustainably sourced and recycled in a closed-loop manner. Minor changes in monomer composition afforded a pressure-sensitive adhesive that functions well in dry and wet conditions, as well as a structural adhesive with strength equivalent to that of conventional epoxies. αLA surgical superglue successfully sealed murine amniotic sac ruptures, increasing fetal survival from 0 to 100%.