Polyester fabric was successively immersed in aqueous polyurethane adhesive solution and the ethanol solution composed of nano silica modified by vinyl triethoxysilane, 2-methacryloyloxyethyl trimethyl ammonium chloride, polyethylene glycol dimethacrylate, trimethylolpropane triacrylate and 2-hydroxy-2-methylpropiophenone. After UV curing, the inorganic and organic composite superhydrophilic coating on polyester fabric was obtained. FT-IR, SEM and contact angle test confirmed the formation of the superhydrophilic coating on the surface of the fabric. The minimum time for water droplets to fully spread on the surface of the superhydrophilic polyester fabric was only 301 ms. The superhydrophilic polyester fabric could be used for oil-water separation. The separation efficiency reached 99.4% and maintained more than 98% even after 50 separation cycles.
Different samples are prepared via molding method using epoxy E-51 as film-forming binder and adjusting the ratio of the curing agent polyether amine and thickening agent PTMEG. The shape-recovering rate, shape-recovering time and the tensile elongation of the samples are tested. The effect of raw materials formula on the shape memory and flexibility of the epoxy coating is examined to obtain the optimal formula. The result shows that the recovering rate and recovering time are the best when the curing degree of epoxy resin is 70%, wherein, the electrochemical performance of the epoxy coating is investigated. It is revealed that the size of the scratch on the coating gets smaller after heating for 30 minutes at 120 ℃, meanwhile, the corrosion potential rises, indicating a good self-healing performance.
The epoxy soybean oil acrylate (AESO) has been widely used in UV-curable coatings, but it is still a great challenge to obtain soybean oil-based photocurable coatings simultaneously having high bio-based content and excellent mechanical properties. In this paper, an isosorbide dimethacrylate (ISDMA) was designed and synthesized as a photocurable reactive diluent. The solubility of reactive diluents for AESO was studied using rheometer. A series of UV-curable coatings were prepared by mixing reactive diluents with AESO, and systematically evaluated their thermo-mechanical, mechanical and basic coating properties. The results showed that ISDMA exhibited good dilution capabilities for AESO, and can effectively increase the glass transition temperature (Tg), storage modulus and hardness of the cured material.
The structure of the core material and the wall material in the microcapsules is introduced, and the conditions for preparing the microcapsules and the typical core materials and wall materials involved in are introduced. The typical preparation methods such as in-situ polymerization, interfacial polymerization, emulsion polymerization, Pickering emulsion polymerization, suspension polymerization, seed microsuspension polymerization, doped seed microsuspension polymerization, polymerization induced phase separation and physical preparation were analyzed, which indicate the progress of microcapsule preparation techniques. The application of microcapsules in functional materials such as phase change energy storage, stealth, self-lubrication and self-healing is presented to reveal the wide application fields of microcapsules. Finally, the application prospect of microcapsules in the new era is given.
The cavitation corrosion and marine fouling on the surface of the ship propeller had been a difficult problem for many years. In this paper, a coating system with good cavitation resistance and antifouling properties for ship propeller was developed, the coating system was composed of high adhesive epoxy primer, elastic epoxy coating, elastic silicone adhesive coating and low surface energy silicone topcoat. Test results showed that the coating system had little gloss loss and the weight loss was less than 5 mg after cavitation corrosion test on painting tool head for 40 h or 100 h. The water test results showed that the coating system had no effect on the hydrodynamic performance of the propeller. The entire coating system was still integrated after thrash test for 300 h. At present, the field result of 11-month actual ship application had been achieved, the overall application of the coating system was good, only a small area of the edge coating was damaged but there was no diffusion phenomenon under the film. Moreover, the fouling organisms attached to the surface could be easily flushed by high-pressure water.
With the rapid depletion of petroleum feed stock and increasing attention to sustainable development and environmental protection, vegetable oils based WPUs with renewable resources as raw materials has attracted more and more attentions. As a typical renewable resource, using vegetable oils as the platform compound to develop WPU has become the focus in industry and science sectors. In this article, the recent advance of the WPU using vegetable oil triglyceride as the basic carbon chain structure via the molecular structure design and preparation of monomer compounds for WPUs preparation has been summarized. Furthermore, the green synthesis of vegetable oil based WPUs and their modification strategy were summarized. The development trends and application prospects of vegetable oil based WPUs were presented according to the development of WPUs at home and abroad.
Waterborne intumescent fire resistant coatings were prepared using waterbrone acrylate as matrix, ammonium polyphosphate, pentaerythritol and melamine as intumescent system and different concentrations of graphene oxide (GO) as synergistic additives. The effects of the GO concentration on the fire retardant properties of the coatings were investigated by small plate burning method measurements. The results showed that trace amount of GO could markedly increase the fire retardant properties of the coatings. When the GO concentration was 0.005wt%, the fire-resistant time of the coatings reached 432 s. Expandable char layer height is increased by 13.04% as compared with that coating without graphene oxide. The structure and morphology of the char layers were characterized by means of infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that the thermal stability of the coating between 300 ℃ and 500 ℃ was increased when GO was added. Besides, the char layers were stronger and better protected, which could provide improved heat insulation and flame resistance.
As many shipyards in China are situated in river inlet, the effects of the long outfitting period in freshwater on marine antifouling coating systems cannot be ignored. It is possible to shorten the development cycle of the antifouling coating systems by an effective accelerated method for evaluating the freshwater resistance. In this paper, the freshwater resistance of the antifouling coating systems is evaluated comprehensively in the laboratory via deionized water (DIW) immersion test or/and exposure and freeze-thaw test after DIW immersion. The field tests demonstrate that the results correlate closely with the results obtained by such an evaluation method, which means the evaluation method can provide reliable basis for the development of the antifouling coating systems.
Natural products (e.g., oleanolic acid, osthole and rotenone) were used as antifouling agents to prepare the marine antifouling paints respectively. Their antifouling efficiency were tested in the sea area of Xiamen. Their antifouling activities were compared with another natural product camptothecin, which was previously reported to have antifouling performance in Xiamen. The results showed that osthole and rotenone exhibited antifouling efficiency in the marine environment within two months, but oleanolic acid did not show antifouling performance in the sea. Camptothecin exhibited stronger antifouling efficiency than the three natural products mentioned above. Furthermore, seven mixed antifoulants were obtained by mixing camptothecin with rotenone at a ratio of 1∶1, and mixing these two natural products with three antifouling agents including cuprous oxide, N-(2,4,6-trichlorophenyl) maleimide (TCPM) and zinc pyrithione (ZPT) at a ratio of 1∶1 respectively. All mixed antifoulants were used to prepare marine antifouling paints which were tested for antifouling efficiency in the marine environment. Three mixed antifoulants, namely camptothecin-TCPM, camptothecin-ZPT and camptothecin-rotenone, were found to exhibit high antifouling potency. In addition, among the antifouling paints prepared in this study, the paint containing camptothecin showed the strongest antifouling efficiency and thus was chosen to be tested in the sea area of Dongshan, Fujian and the sea area of Lingshui, Hainan. The results of this field test showed that the paint containing camptothecin had stable and outstanding antifouling efficiency both in Dongshan and Lingshui, and the efficiency lasted for more than 13 months. This study provided important data for the development of natural product-based antifouling paints.
With the continuous development of microcapsule self-healing technology, Microcapsules have increasingly shown outstanding application advantages in protective coatings and other fields. The formulation design and structural properties of single-walled and double-walled self-healing microcapsules as well as the simulation and research status of microcapsules are reviewed. Meanwhile, the progress of the self-healing microcapsules containing isocyanate, epoxy resin, corrosion inhibitor and vegetable oil as repairing agents for protective coating is described. The problems existing in the development of microcapsule self-healing technology are summarized. An approach of the microcapsule self-healing technology combined with molecular dynamics simulation is proposed, which is expected to establish the correlation between macroscopic microstructure and properties of microcapsules, and the further investigation on the self-healing mechanism of microcapsules can be realized.
The concrete suffers from deterioration caused by permeation of ions and water due to its porous structure. It is also easy to crack with brittleness in nature, which speeds up the corrosion. The anticorrosion of concrete plays an important role in infrastructure and industry construction. An coating is one of the most effective approaches to protect concrete. In this paper, the corrosive mechanism of concrete is introduced. The recent progress in coatings for concrete protection, including silane and siloxane-based coating, surface layer, pore-sealing layer is reviewed. In particular, a novel permeable and in-situ curable anticorrosive coating (PSEp) is introduced in terms of its protective mechanism and anticorrosive properties. Finally, the future trends of anticorrosive coatings for concrete are given.
The research progress of graphene and graphene oxide in modified organic anticorrosive coatings is reviewed. The modification and dispersion of graphene and graphene oxide, functional integration of graphene and its application in organic anticorrosive coatings, and the influence of conductivity of graphene and graphene oxide on organic anticorrosive coatings are mainly introduced. At present, one of the greatest difficulties in the application of graphene modified organic anticorrosive coating in industrial applications is how to enable the graphene modified organic anti-corrosion coating an active protection function. If the thickness of the nano-oxides layer loaded on the surface of graphene is increased up to submicron level and it has the characteristics of coarse porosity and strong bonding strength, the organic anticorrosive coatings modified by nano-oxides/graphene composite will have the properties of the barrier properties and active protection.
Self-healing superhydrophobic coatings can extend the service life of coatings, which is one of the hottest research topics in recent years. The mechanism of superhydrophobic self-healing coatings is summarized, including the restoration of surface morphology and the supplement of low surface energy components. The recovery of surface topography can be achieved through dynamic chemical bonding and gas compensation. The supplement of low surface energy components relies on the surface energy to drive the underlying low surface energy components to migrate to the surface of the coating under stimulus conditions. At present, there are new research directions such as the use of shape memory alloys for self-healing large-scale surface structures, reducing dependence on external stimuli to achieve autonomous self-healing processes, self-repairing with molecular structures, and self-healing multi-layer slippery liquid infused porous surface (SLIPS) design. The synergic effect of the multiple functions is introduced, which promotes the overall performance of the coating to be optimal. The synergic effect of superhydrophobic self-healing multifunctional fiber, superhydrophobic anticorrosive self-healing coating and superhydrophobic conductive self-healing coating are introduced. This provides new ideas for the design of multifunctional coatings. Finally, the prospects of the self-healing superhydrophobic coatings are put forward.
