Structural Adhesives Tapes Based on a Solid Epoxy Resin and Multifunctional Acrylic Telomers

In order to improve the mechanical and bond properties of epoxy adhesives for their wide scope of applications, modified epoxy adhesives were produced in this study with SiO2 nanoparticles of 20 nm in size, including inactive groups, NH2 active groups, and C4H8 active groups. The mechanical properties of specimens were examined, and an investigation was conducted into the effects of epoxy adhesive modified by three kinds of SiO2 nanoparticles on the bond properties of carbon fiber reinforced polymer and steel (CFRP/steel) double lap joints. According to scanning electron microscopy (SEM), the distribution effect in epoxy adhesive of SiO2 nanoparticles modified by active groups was better than that of inactive groups. When the mass fraction of SiO2-C4H8 nanoparticles was 0.05%, the tensile strength, tensile modulus, elongation at break, bending strength, flexural modulus, and impact strength of the epoxy adhesives reached their maximum, which were 47.63%, 44.81%, 57.31%, 62.17%, 33.72%, 78.89%, and 68.86% higher than that of the EP, respectively, and 8.45%, 9.52%, 9.24%, 20.22%, 17.76%, 20.18%, and 12.65% higher than that of the inactive groups of SiO2 nanoparticles, respectively. The SiO2 nanoparticles modified with NH2 or C4H8 active groups were effective in improving the ultimate load-bearing capacity and bond properties of epoxy adhesives glued to CFRP/steel double lap joints, thus increasing the strain and interface shear stress peak value of the CFRP surface.

Section: Introductionmentioning

confidence: 99%

Enhancement of Mechanical and Bond Properties of Epoxy Adhesives Modified by SiO2 Nanoparticles with Active Groups

Long

2022

“…They are commonly used as matrix materials in composites, which are extensively applied in the aerospace and automotive industries to produce lightweight, high-strength parts [ 35 ]. Epoxy resins are also popular as adhesives, sealants, and coatings due to their excellent adhesive properties and chemical resistance [ 36 ]. They are used to bond a variety of materials, making them essential in many industrial applications, particularly in the construction industry, where they are used to repair and strengthen concrete parts or protect steel structures from corrosion and wear [ 37 ].…”

Section: Epoxy Polymersmentioning

confidence: 99%

Towards Sustainable Recycling of Epoxy-Based Polymers: Approaches and Challenges of Epoxy Biodegradation

Klose,

Meyer-Heydecke,

Wongwattanarat

et al. 2023

Epoxy resins are highly valued for their remarkable mechanical and chemical properties and are extensively used in various applications such as coatings, adhesives, and fiber-reinforced composites in lightweight construction. Composites are especially important for the development and implementation of sustainable technologies such as wind power, energy-efficient aircrafts, and electric cars. Despite their advantages, their non-biodegradability raises challenges for the recycling of polymer and composites in particular. Conventional methods employed for epoxy recycling are characterized by their high energy consumption and the utilization of toxic chemicals, rendering them rather unsustainable. Recent progress has been made in the field of plastic biodegradation, which is considered more sustainable than energy-intensive mechanical or thermal recycling methods. However, the current successful approaches in plastic biodegradation are predominantly focused on polyester-based polymers, leaving more recalcitrant plastics underrepresented in this area of research. Epoxy polymers, characterized by their strong cross-linking and predominantly ether-based backbone, exhibit a highly rigid and durable structure, placing them within this category. Therefore, the objective of this review paper is to examine the various approaches that have been employed for the biodegradation of epoxy so far. Additionally, the paper sheds light on the analytical techniques utilized in the development of these recycling methods. Moreover, the review addresses the challenges and opportunities entailed in epoxy recycling through bio-based approaches.

“…Epoxy resins are widely used as matrices in advanced composites, massively applied in industries such as construction, aerospace, marine and automotive for lightweight and mechanically strong parts [ 24 ]. Other applications of epoxy resins include coatings, sealants and adhesives, because of their outstanding adhesive properties and chemical resistance [ 25 ]. In construction, epoxy resins are applied in repairing and strengthening concrete and anticorrosion and wear-protection agents for steel structures [ 26 ].…”

Section: Introductionmentioning

confidence: 99%

Surface Degradation of DGEBA Epoxy Resins Cured with Structurally Different Amine Hardeners: Effects of UV Radiation

Varganici,

Rosu,

Rosu

et al. 2023

In this study, the effects of three diamine curing agents (aromatic, cycloaliphatic, aliphatic) on the photochemical behavior of bisphenol A diglycidyl ether networks were comparatively examined. In order to monitor structural changes and study the curing agents’ action mode, the cured epoxy resins were characterized before and after photoirradiation by means of Fourier-transform infrared spectroscopy, contact angle, differential scanning calorimetry, scanning electron microscopy, and energy-dispersive X-ray analysis, mass loss, and color modification measurements. Water absorption tests were also conducted. The cured epoxy resins are to be used in different multicomponent polymer materials for outdoor protection. The presence of the cycloaliphatic hardener led to reduced water absorption, and after UV irradiation, an increase in the glass transition temperature and lowest mass loss of the corresponding cured epoxy resin compared to the ones cured with aromatic and aliphatic hardener.