Fig 2 - available via license: Creative Commons Attribution-NonCommercial 3.0 Unported
Content may be subject to copyright.
Schematic of preparation and self-healing behavior of UV-curable material based on disulfide bond exchange: (a) before UV irradiation; (b) after UV irradiation; (c) damaged material; (d) self-healed material This figure has been adapted from ref. 24 with permission from Elsevier, copyright 2019.
Source publication
Self-healing is the ability of a material to recover from physical damage. Because self-healing is crucial to environmental protection and sustainable development, several photochemical approaches, including those involving disulfide group, reversible Diels-Alder reaction, hydrogen bond cleavage, reformation, photo dimerization, and self-filling sy...
Context in source publication
Context 1
... coatings increased signicantly with the increase in disulde bond content. The coating still exhibited favorable self-healing abilities when a UV light source was used instead of high-pressure mercury lamp to eliminate the inuence of the thermal effect of the lamp, and the coatings were compatible with commercial acrylic resin, shown in Fig. 2. Li et al. 25 synthesized UV-curable water-based polyurethane self-healing coatings with polysulde prepolymer as the main material through sulydryl-ene photopolymerization. Because of the exchange of disulde bonds in the prepared coating, the coating not only had self-healing properties but also exhibited excellent anticorrosion ...
Similar publications
This research is based on the social approach of design, through the satisfaction of individual and collective human needs, understanding this approach as the main actor in the mediation of the economic, social, and sustainable development of the community. It is intended to analyze the different theoretical positions that supports the construction...
The smart tourism concept emerged from smart city development and is a particular application area within smart city initiatives. Smart tourism is broadly applied as a strategic tool to enhance the competitiveness of tourism destinations. This study creates a framework to identify, explore, and rate the effective factors of developing smart tourism...
The city's urban structure is affected by many factors
including the evolution of transport systems, transportation
technology, and kinds of transport at the end of the
nineteenth century up to the twenty-first century, which
led to a significant transformation of cities urban structure
as a result of its fast development, the technological
develop...
Aim. The presented study aims to develop a theoretical basis and a conceptual approach to the digital strategizing of industrial systems based on the paradigm of sustainable eco-innovation development, circular business models, and the transformational impact of Industry 5.0 technologies.
Tasks. The authors propose a theoretical basis for digital s...
SDGs (Sustainable Development Goals) are global goals that aim to bring people together to better people's lives. The 2030 Agenda for Sustainable Development includes education for sustainable development (ESD) as a crucial component. Its goals are one of the targets of SDG 4.7 on education, and it is seen as a key to achieving all 17 SDGs. The pap...
Citations
... Importantly, the described initiators are characterized by short induction time of polymerization, whereby the curing of compositions occurred within 60-400 s. Surprisingly, some sensitizers in the presence of iodonium salt and amine also initiated polymerization processes with sunlight [76]. It is worth mentioning the useful of organic chromophores in self-healing processes, which are crucial for the production of new-generation materials, especially smart coatings and polymers [77,78]. The connection of light as an external stimulus and appropriate photoinitiating system may be a good direction for the regeneration of various materials. ...
... The originally suggested pathway assumes the photoinduced electron transfer from the excited state of a photocatalyst (PC) to the thiocarbonylthio-containing molecule (known also as RAFT agent or chain transfer agent, CTA). In the next step, the fragmentation of this species It is worth mentioning the useful of organic chromophores in self-healing processes, which are crucial for the production of new-generation materials, especially smart coatings and polymers [77,78]. The connection of light as an external stimulus and appropriate photoinitiating system may be a good direction for the regeneration of various materials. ...
Light-activated polymerization is one of the most important and powerful strategies for fabrication of various types of advanced polymer materials. Because of many advantages, such as economy, efficiency, energy saving and being environmentally friendly, etc., photopolymerization is commonly used in different fields of science and technology. Generally, the initiation of polymerization reactions requires not only light energy but also the presence of a suitable photoinitiator (PI) in the photocurable composition. In recent years, dye-based photoinitiating systems have revolutionized and conquered the global market of innovative PIs. Since then, numerous photoinitiators for radical polymerization containing different organic dyes as light absorbers have been proposed. However, despite the large number of initiators designed, this topic is still relevant today. The interest towards dye-based photoinitiating systems continues to gain in importance, which is related to the need for new initiators capable of effectively initiating chain reactions under mild conditions. In this paper we present the most important information about photoinitiated radical polymerization. We describe the main directions for the application of this technique in various areas. Attention is mainly focused on the review of high-performance radical photoinitiators containing different sensitizers. Moreover, we present our latest achievements in the field of modern dye-based photoinitiating systems for the radical polymerization of acrylates.
Ultraviolet (UV)-curable coatings were prepared using rosin-based polyurethane as an oligomer with different active diluents and crosslinking monomers. The effects of different components level on the properties of the polyurethane coatings were investigated, and the effects of the mass ratio of the active diluents, crosslinking monomers, adhesion promoting monomers, photoinitiators, and curing times on the polyurethane coatings were discussed. The results showed that when hydroxypropyl acrylate was used as an end-capping agent, 40% of methyl methacrylateas a reactive diluent, 10% of dimethylol propane tetracrylate as a crosslinking monomer, 7% of hydroxyethyl diacrylate phosphate as an adhesion promoter, 4% of 1173 as a photo-initiator, and a curing time of 120 s. UV-curable resin exhibited the best coating properties: pendulum hardness of 0.63, 60° gloss of 153.9, adhesion of grade 2, impact strength of 500 J m ⁻² , and the water resistance exceeding 30 days.
Self‐repairing materials aim to replicate nature's repair mechanisms, but their current properties are inadequate for commercialization due to the trade‐off between repair and mechanical properties. An environmentally responsive low‐temperature self‐healing aqueous polyurethane with different sequence structures was developed in which the WPU‐MD/APDS system exhibited excellent performance. Statically, the incorporation of MD (1,8‐diamino‐P‐menthane) enhances hydrogen bonding within the system and facilitates reversible weak dynamic bonding; microphase separation enables aggregation of disulfide bonds in the hard‐phase domain, thereby improving disulfide bond exchange rates. Dynamically, the inclusion of MD introduces a rigid ring structure and promotes microphase separation with increased hydrogen bonding, leading to enhanced mechanical properties of the materials. The material exhibited tensile strength of 27.37 MPa, elongation at break of 1353%, excellent elastic recovery ability, and high tensile toughness of 136 MJ m⁻³; a sample with thickness of 0.2 mm lifted weight greater than its own weight into 40,000 times without damage recovery at 40°C. Rheological analysis confirmed its self‐healing property at room temperature.
Disulfide-containing coatings are gaining importance due to the peculiar properties and responsiveness of S-S bonds, which make them suitable for several applications, first among them self-healable materials. Herein, a novel UV-curable diacrylated polyurethane monomer containing disulfide bonds (DSPDA) was synthesized through a one-step process without the need for further purification, as assessed by NMR and HPLC analyses. The photopolymerization kinetics of the monomer was studied through real-time FTIR, highlighting a fast and complete conversion even in the absence of a photoinitiator, thus demonstrating the self-initiating capabilities of the synthesized monomer based on the disulfide cleavage upon UV light exposure. Clear coatings having a T g = 72 °C were obtained. The self-healing ability of the films was assessed: thanks to the presence of disulfide bonds in the cured coating, a recovery of the damage was obtained in only 10 min by heating at 100 °C.
Ultraviolet (UV)-curable coatings made from acrylated epoxy soybean oil (AESO) combine the advantages of renewable biobased resources and energy-efficient UV-curable materials, so they serve as the primary research objects for developing eco-friendly coatings. However, due to the lack of rigid structure, the hardness and thermal stability of AESO are much lower than those of petroleum-based epoxy acrylate (EA). Therefore, high-performance soybean oil-based UV-curable oligomers were prepared by using dimethylolpropionic acid (DMPA) and methacrylic anhydride (MAAH) to modify ESO and then blended with high-functional active diluent trimethylolpropane triacrylate (TMPTA). Furthermore, FTIR, 1H NMR, and GPC were used to analyze the molecular structure and molecular weight of the oligomers. The oligomers (DMA/MAAESO and DMA/MAAESO-TM) had high esterification rate, curing degree, and good storage stability. The cured coatings from DMA/MAAESO and DMA/MAAESO-TM oligomers had significantly improved thermal stability, tensile, and coating properties. In all samples, DMA/MAAESO-TM cured coating had excellent coating performances. The glass transition temperature (Tg) of DMA/MAAESO-TM was 78.1°C, and its crosslink density (νe) was 6.87 × 10−3 mol/cm3. The hardness, curing time, gloss, flexibility, and impact resistance were H, 20 s, 108.5, 1 mm, and 50 cm, respectively.
