Chunyan Cui  Yage Sun  Xiongfeng Nie  Xuxuan Yang  Fushuo Wang  Wenguang Liu 《Advanced functional materials》2023,33(49):2307543

α-lipoic acid (LA), a coenzyme, has proved to have excellent antioxidant and antibacterial activities; however, its intrinsic hydrophobicity and metastability of polyLA remains a major challenge for the application of LA-based bulk materials in biomedical field. Herein, a self-stabilized LA-based deep eutectic supramolecular polymer ( LA-DESP) adhesive is created by one-step heating the mixture of LA and sodium α-lipoate (LA-Na) (S-, R-isomer, racemate) without introducing any exogenous stabilizing molecules. The underlying deep eutectic effect in LA/LA-Na is unveiled to be originated from the multiple hydrogen bonds between polyLA and polyLA-Na, which not only prevent polyLA depolymerization but also lower the melting point of LA-DESP to the near body and pathological temperature. Copolymerization of LA and LA-Na slows down the dissociation of polyLA-Na, thus affording sustainable release of bioactive LA-based small molecules and satisfactory antioxidant and antibacterial functions. Also, the LA-DESP exhibits fast and tough adhesion to diverse substrates, including wet tissues, relying on its in situ curing property and rich carboxyl groups. The LA-DESP is explored as a tissue sealant, which can well replace surgical suture to enhance the wound healing of skin incision in a rat model. The unprecedented deep eutectic effect will provide a new strategy for the development of LA-based bioadhesives.  相似文献   

    

Vitus Hupp;Bernhard Schartel;Kerstin Flothmeier;Andreas Hartwig; 《火与材料》2024,48(1):114-127

Pressure-sensitive adhesive tapes are used in several industrial applications such as construction, railway vehicles and the automotive sector, where the burning behavior is of crucial importance. Flame retarded adhesive tapes are developed and provided, however, often without considering the interaction of adhesive tapes and the bonded materials during burning nor the contribution of the tapes to fire protection goal of the bonded components in distinct fire tests. This publication delivers an empirical comprehensive knowledge how adhesive tapes and their flame retardancy effect the burning behavior of bonded materials. With a special focus on the interaction between the single components, one flame retarded tape and one tape without flame retardant are examined in scenarios of emerging and developing fires, along with their bonds with the common materials wood, zinc-plated steel, mineral wool, polycarbonate, and polymethylmethacrylate. The flame retardant significantly improved the flame retardancy of the tape as a free-standing object and yielded a V-2 rating in UL 94 vertical test and raised the Oxygen Index by 5 vol.%. In bonds, or rather laminates, the investigations prove that the choice of carrier and substrates are the factors with the greatest impact on the fire properties and can change the peak of heat release rate and the maximum average rate of heat emission up to 25%. This research yielded a good empirical overall understanding of the fire behavior of adhesive tapes and bonded materials. Thus, it serves as a guide for tape manufacturers and applicants to develop tapes and bonds more substrate specific.  相似文献   

The Structure–Property Correlations in Dry Gelatin Adhesive Films     

Yasmine Mosleh  Willem de Zeeuw  Marlies Nijemeisland  Johan C. Bijleveld  Paul van Duin  Johannes A. Poulis 《Advanced Engineering Materials》2021,23(1):2000716

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Dr.-Ing. Christiane Kothe  Anna Bodenko  Dr.-Ing. Felix Nicklisch  Prof. Dr. ir. Christian Louter 《Bautechnik》2020,97(5):317-325

Thin glass in façades: adhesive joints for thin glass composite panels with 3-D printed polymer cores Thin glass is typically applied for displays on devices. Also, it enables new applications in architecture for example in glass façades. Due to its high strength and small thickness (0.1–2 mm) thin glass is very flexible, lightweight and easily bendable. However, thin glass cannot simply replace conventional façade glazing. To avoid too high deformations of the glazing as a result of the high flexibility, it has to be stiffened. An appropriate solution is the use of sandwich panels consisting of two thin glass panes with an inner polymer core. To achieve lightweight façade elements, 3-D printed polymer structures are used instead of a solid core. The present study is dedicated to find a suitable adhesive to bond the polymer core to the thin glass. The mechanical and thermomechanical performances of different combinations of typical 3-D printed polymers and transparent adhesives are evaluated. In addition, the influences of temperature and UV aging that occur in the area of the façades are investigated.  相似文献   

    

Rudolf Beran  Lucie Zarybnicka  Dita Machova 《应用聚合物科学杂志》2020,137(37):49095

Rigid polyurethane (PUR) foams are widely used as heat insulation material in construction industry or for electronic appliances manufacturing. After finishing their life-time, it is necessary to eliminate foam wastes. The aim of this study was to prepare a pair of industrial PUR adhesives of medium viscosity containing recycled rigid PUR foam. Three methods of milling were tested: knife-milling, two-roll milling, and ball-milling. Only two-roll milling gives the PUR micro-powder usable for following adhesives modification. The micro-powder was used as passive filler in PUR adhesives and potential reactivity for polyol pack replacement was studied. Hydroxyl and amine numbers were determined in mixture with virgin polyol. One-component PUR prepolymer adhesive was prepared using various dosages of the micro powder and the tensile strength of bound wood was measured. As additional parameters, also free film adhesive mechanical parameters were tested and particle size distribution of the micro powder was analyzed. Two adhesive formulations were prepared for independent evaluation of the micro powder reactivity. The results showed growing of the mechanical strength of wood bonding with growing dosage of the micro powder.  相似文献   

    

Qian Yan  Shujun Zhao  Haijiao Kang  Shifeng Zhang 《应用聚合物科学杂志》2020,137(39):49176

The development of natural fiber-reinforced composites is environmentally friendly and therefore presents great potential; however, these composites are characterized by poor water resistance and interfacial bonding, which therefore limits its practical applications. This study reported a facile and novel approach for the construction of a high-performance microfibrillated cellulose (MFC) elastomer using thiol-functionalized polyurethane (PU-SH) with the assistance of a bioinspired dopamine platform. This elastomer was then employed as a reactive reinforcer to improve soy protein isolated (SPI) adhesive. The surface modification of MFC included the formation of a polydopamine (PDA) layer and Michael addition reactions between PU-SH and PDA, which were characterized by the Fourier-transform infrared spectroscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy measurements. It was found that the high-functional MFC elastomer served as a reactive cross-linker that gave rise to multiple physical and chemical interactions with the SPI matrix. This resulted in the optimization of the crosslinking system, which ultimately contributed to the solution of the bottleneck issues for natural fiber-reinforced composites. Consequently, the modified SPI-based adhesives notably enhanced the shear strength to 1.38 MPa, displaying a 236.6% increment compared to the unmodified adhesive. This strategy may provide a new insight into the design and preparation of superior natural plant-reinforced composites.  相似文献   

    

Jing Sun  Juanjuan Su  Chao Ma  Robert Göstl  Andreas Herrmann  Kai Liu  Hongjie Zhang 《Advanced materials (Deerfield Beach, Fla.)》2020,32(6):1906360

Protein-based structural biomaterials are of great interest for various applications because the sequence flexibility within the proteins may result in their improved mechanical and structural integrity and tunability. As the two representative examples, protein-based adhesives and fibers have attracted tremendous attention. The typical protein adhesives, which are secreted by mussels, sandcastle worms, barnacles, and caddisfly larvae, exhibit robust underwater adhesion performance. In order to mimic the adhesion performance of these marine organisms, two main biological adhesives are presented, including genetically engineered protein-based adhesives and biomimetic chemically synthetized adhesives. Moreover, various protein-based fibers inspired by spider and silkworm proteins, collagen, elastin, and resilin are studied extensively. The achievements in synthesis and fabrication of structural biomaterials by DNA recombinant technology and chemical regeneration certainly will accelerate the explorations and applications of protein-based adhesives and fibers in wound healing, tissue regeneration, drug delivery, biosensors, and other high-tech applications. However, the mechanical properties of the biological structural materials still do not match those of natural systems. More efforts need to be devoted to the study of the interplay of the protein structure, cohesion and adhesion effects, fiber processing, and mechanical performance.  相似文献   

    

Alona Shagan  Wei Zhang  Manisha Mehta  Shira Levi  Daniel S. Kohane  Boaz Mizrahi 《Advanced functional materials》2020,30(18)

Tissue bioadhesives are widely used in dermatology, surgery rooms, and in the field. Despite their advantages over sutures and staples, currently available tissue glues are limited by their mechanical properties and toxicity. Here, a new approach is described for wound closure that is based on a biocompatible, low melting point four‐armed N‐hydroxy succinimide‐modified polycaprolactone (star‐PCL‐NHS). Star‐PCL‐NHS is inserted into a hot melt glue gun, melts upon minimal pressure, and is extruded directly onto the wound, where it solidifies, bonding strongly with both edges of the wound. Changes in molecular weight allow control of adhesive strength, melting point, and elasticity properties. In vitro and in vivo evaluations confirm the biocompatibility of this system. The straightforward synthetic scheme and the simple delivery method, combined with the desirable mechanical properties, tunability, and tissue compatibility, are desirable traits in wound management.  相似文献   

    

Zhuo Li  Jijun Wan  Lu Zhang  Jianfeng Cui  Shugao Zhao 《应用聚合物科学杂志》2017,134(48)

The objective of this study was to evaluate the effects of heat and moisture on the characteristics and tensile properties of resorcinol‐formaldehyde‐latex (RFL)‐coated rayon cords and their adhesion to the natural rubber (NR)/styrene‐butadiene rubber (SBR) matrix. The water absorption ratio, shrinking percentage, breaking force, and elongation at break of the cords, which were treated under various temperature‐humidity conditions, were tested, and an attenuated total reflection (ATR)‐Fourier transform infrared (FTIR) spectroscopy was used to investigate the chemical changes of the outer RFL layer. The static adhesion was investigated by an H pull‐out test, and the evolution of the adhesive properties of the RFL‐coated rayon cord/rubber matrix was tracked by an elastomer testing system. A scanning electron microscope (SEM) was employed to observe the interfacial fracture caused by both H pull out and fatigue. The results of this investigation show that the moisture absorption significantly affects the characteristics and the mechanical properties of rayon cords. The chemical state of the RFL layer and the static adhesion of the cord/rubber matrix were not obviously affected, but the interfacial fatigue life was extended due to the decrease of the load in the second of three fatigue stages, which was caused by a reduction in the modulus of the rayon cords. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45559.  相似文献   

    

Srijoni Sengupta  Tamalika Das  Uttam Kumar Ghorai  Abhijit Bandyopadhyay 《应用聚合物科学杂志》2017,134(42)

This is a first report of the synthesis and characterization of acrylic copolymers from methyl methacrylate (MMA) and butyl acrylate (BA) with hyperbranched architecture. The copolymers were synthesized using a free radical polymerization (Strathclyde method) in emulsion technique. Divinyl benzene was used as the brancher which acted as a comonomer and 1‐dodecanethiol was used as a chain terminating agent. A linear copolymer from MMA and BA was also synthesized for comparison. The hyperbranched architecture was established from spectroscopic and rheological measurements. The gel permeation chromatography showed all hyperbranched copolymers were low molecular weight with lower polydispersity index (PDI) ( 23,000, PDI ～ 2.00) compared to the linear grade ( 93,000, PDI ～ 2.20). They were more spherical and achieved lower viscosity (yet higher solubility, >90%) than the linear grade (<50%) which was mostly open ended. Lower viscosity at equivalent solid content made the hyperbranched polymers a potential binder for adhesive and coating application. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45356.  相似文献