Adhesive prepregs and composite materials on their basis

The properties of high-strength and high-elasticity film-forming adhesives, high-strength cold- and hot-setting adhesive pastes, functional adhesives for metals, and various nonmetal and composite materials are reviewed. The properties of self-adhesive materials of different grades used for temporary repair of airframe surfaces are also described.     

Properties of adhesives and adhesive materials used in aviation industry

Methods for developing adhesives and adhesive material used in the structures of almost all units of aviation machinery are described step by step. The properties of high-strength film-forming adhesives; adhesive prepregs; sandwich-type aluminum-polymer materials (SIALs); cold- and hot-setting adhesives intended for gluing metals, different nonmetallic materials, and combined joints; and self-adhesive film materials of ZPPK and FAS grades are given. It is also shown where and for which purposes these adhesives are applied.     

Adhesives for aviation equipment

The properties of high-strength and high-elastic film adhesives, high-strength cold- and hot-setting adhesive pastes, adhesives intended for bonding of metals, different nonmetallic and composite materials are overviewed. The properties of self-adhesive materials of different grades used for temporary repair of airframe surfaces are also described.     

Investigation of artificial resin-based adhesives in works carried out by the all-Russia Scientific Research Institute of Aviation Materials in 1936–1937

The main preconditions for developing principally new (for the examined period of time) adhesives based on artificial resins are presented. The results of application of the combined (casein and resin) adhesives, adhesives based on novolak, karbolit and barite phenol formaldehyde resins are given. It is shown that the phenol-barite resin of VIAM-6 grade was the most suitable for the aviation industry at that time.     

Investigation of the artificial resin-based adhesives in works carried out by the All-Russia Scientific Research Institute of Aviation Materials in 1938–1939

The main preconditions for developing principally new (for the examined period of time) adhesives based on artificial resins are presented. The results of application of the combined (casein and resin) adhesives, adhesives based on novolak, karbolit and barite phenol formaldehyde resins are given. It is shown that the phenol-barite resin of VIAM-6 grade was the most suitable for the aviation industry at that time.     

A technology for manufacturing tapes and pastes of powder solders on organic binders

The results of the development of new domestic semifinished products of nondeformable solders, such as tapes and pastes of solders on an organic binder, are presented. It was shown that the use of a copolymer of BMK-5 acrylic resin as a binder for semifinished products in the form of a tape; and the MBM-5S acrylic dispersion, in the form of pastes, is optimum for meeting such requirements as absence of ash residue during high-temperature heating in vacuum, manufacturability, and shelf life.     

Towards the identification of plant and animal binders on Australian stone knives

There is limited information regarding the nature of plant and animal residues used as adhesives, fixatives and pigments found on Australian Aboriginal artefacts. This paper reports the use of FTIR in combination with the chemometric tools principal component analysis (PCA) and hierarchical clustering (HC) for the analysis and identification of Australian plant and animal fixatives on Australian stone artefacts. Ten different plant and animal residues were able to be discriminated from each other at a species level by combining FTIR spectroscopy with the chemometric data analysis methods, principal component analysis (PCA) and hierarchical clustering (HC). Application of this method to residues from three broken stone knives from the collections of the South Australian Museum indicated that two of the handles of knives were likely to have contained beeswax as the fixative whilst Spinifex resin was the probable binder on the third.     

Studying possibility of using melamine-urea-formaldehyde resin-based adhesives with separately applied components in wooden structures

Complex accelerated testing results on the strength and stability of glued joints obtained by separate applications of binder and hardener to glued surfaces in wooden structures are presented. The obtained data confirm the possibility of switching the wooden structure industry to more manufacturable melamineurea-formaldehyde resin-based adhesives with components separately applied to glued surfaces.     

Single-component polyurethane adhesive for elastic materials

General information on polyurethane adhesives is outlined. Polyurethane adhesive is presented that was developed by ZAO Novbytkhim mainly for applications in footwear and the production of leather goods to join materials such as leather, fabric, polyurethane, resin, and some types of plastics.     

Cure kinetics of epoxy-amine resins used in the restoration of works of art from glass or ceramic

The cure kinetics of two epoxy/amine resins, Araldite 2020 and AY103-HY956 widely used as adhesives in the restoration of works of art from glass or ceramic was investigated using FTIR spectroscopy. These resins are two-part adhesives, consisting of a resin - A, based on a diglycidyl ether of bisphenol A, and a hardener - B which is either a cycloaliphatic amine (isophorone diamine) for Araldite 2020, or a mixture of three aliphatic amines in HY956. The study was based on the collection of IR spectra, in the middle range (4000-600 cm⁻¹), of mixtures of resin and hardener at different proportions and isothermal temperatures (22-70 °C) as a function of curing time. A kinetic model was employed to simulate the experimental data using two kinetic rate constants. Diffusion control was incorporated to describe the cure behaviour at high degrees of conversion. From fitting to experimental data the kinetic and diffusional parameters were estimated, together with the activation energies of the kinetic and autocatalytic rate constants. It was found that higher degrees of curing are obtained at higher temperatures and increased amounts of hardener. Differences in the performance of the two adhesives are explained based on the type of the amines used as hardener.     

Resistance of Rosin-Modified Polyester Resin to Thermal Oxidative Degradation

The resistance of rosin-modified polyester resin to thermal oxidative degradation was studied. This resin can be used as organic binder in low-temperature corrosion-inactive soldering pastes.     

一种长链叔胺pH敏感抗菌牙体修复材料的合成与抗菌性能

口腔粘结剂常被用于粘结复合树脂和牙本质或牙釉质,但由于残留细菌会导致继发龋病从而使得粘结剂修复体不能提供长期疗效,目前市场上使用的粘结剂均无法避免细菌滋生。本文采用两步法合成了一种甲基丙烯酸酯基封端的长链叔胺,通过柱层析进行纯化,其结构经¹H NMR和FT-IR表征,并对其抗菌性能进行了研究。结果表明：该材料可通过质子化作用提升口腔pH值抑制细菌滋生。     

Study on affecting factors of curing rate in ultraviolet curing adhesives containing modified acrylic ester prepolymers

Abstract

Ultraviolet (UV) curing adhesives have been extensively utilized in fields of health care and electronic components due to low energy consumption and solvent pollution. The most used system is modified acrylic ester system whose merits are low cost, high reliability and tensile strength. However, higher UV curing rate is still pursued especially in field of quick dry adhesives as well as influencing factors of curing rate are very complex. For clarifying affecting factors of curing rate as well as achieving higher curing rate, in this work, several UV curing adhesives with acrylic photosensitive resin prepolymers modified by epoxy and polyurethane were prepared. The impacts of class and content of radical photo-initiators, prepolymers and reactive diluents on UV curing rate were deeply researched. Moreover, the influence of oxygen polymerization inhibition on curing rate was discussed as well. The significantly elevated curing rates were obtained in as-prepared adhesives, in comparison with commercial ones. This work might offer a facile and effective strategy to obtain the promising high-performance modified acrylic ester prepolymer bearing UV curing adhesives with a significantly elevated high curing rate by well controlling these investigated affecting factors.     

PREPARATION AND PROPERTIES OF EPOXY RESIN MODIFIED BY LIQUID CHLOROPRENE-HYDROXYETHYLMETHACRYLATE COPOLYMER

The epoxy resin modified by liquid chloroprene-hydroxyethylmethacrylate copolymer (CP-HEMA) is a new kind of structural adhesives with good mechanical properties. By changing its mole-cular structure, it may also have such desirable properties as retardation of combustion, enduringweather aging, inert oils and chemicals. A series of the thermosets of the epoxy resin modifiedby CP-HEMA used as a toughener were prepared. The effects of CP-HEMA content, catalyst con-tent and curing temperature on the mechanical properties of modified epoxy resin system were studied.The thermal weight-loss curves were examined. The two-phase morphology was observed and dis-cussed.     

Formaldehyde-Free Resins for the Wood-Based Panel Industry: Alternatives to Formaldehyde and Novel Hardeners

Due to its carcinogenic properties, the presence of formaldehyde in resins and other industrial products has been a subject of great concern in recent years. The presented review focuses on modern alternatives for the production of wood-based panels; i.e., substitutes for formaldehyde in the production of amino and phenolic resins, as well as novel hardeners for formaldehyde-free wood adhesives. Solutions in which formaldehyde in completely replaced are presented in this review. Recent advances indicate that it is possible to develop new formaldehyde-free systems of resins with compatible hardeners. The formaldehyde substitutes that have primarily been tested are glyoxal, glutaraldehyde, furfural, 5-hydroxymethylfurfural, and dimethoxyethanal. The use of such substitutes eliminates the problem of free formaldehyde emission originating from the resin used in the production of wood-based panels. However, these alternatives are mostly characterized by worse reactivity, and, as a result, the use of formaldehyde-free resins may affect the mechanical and strength properties of wood-based panels. Nonetheless, there are still many substantial challenges for the complete replacement of formaldehyde and further research is needed, especially in the field of transferring the technology to industrial practice.     

Lignocellulosic composite

Banana pseudostem fiber which is a lignocellulosic material, relatively inexpensive, and abundantly available was assessed in terms of its fiber‐matrix adhesion and dispersion in composites. Different types of adhesives were used. The mechanical and water absorption properties were investigated. Overall, for the produced composites, the incorporation of sawdust‐urea‐formaldehyde resin into prehydrolyzed banana fiber resulted in the best mechanical properties. Good adhesion‐fiber interaction is believed to be responsible for the good ultimate performance. The superior reinforcing characteristics of sawdust resin were shown by scanning electron microscopy (SEM), which revealed better fiber‐matrix adhesion. Water absorption tests revealed that the presence of the adhesives affected the amount of water absorbed. Copyright © 2004 John Wiley & Sons, Ltd.     

Insertion of nano-crystalline cellulose into epoxy resin via resilin to construct a novel elastic adhesive

Development of high-performance bio-nanocomposite adhesives is of high interest due to their environmentally friendly nature and superior mechanical properties in outdoor environments. Nano-crystalline cellulose (NCC) and resilin are among the most promising bio-nanofillers, providing strength and elasticity, respectively. A novel bio-nanocomposite comprised of NCC and resilin fused to a cellulose binding domain (Res.-CBD) is presented. As a case study, commercial epoxy adhesive was chosen as a matrix for the bio-nanocomposite adhesive. Insertion of hydrophilic NCC into hydrophobic resins, such as epoxy, is typically performed using solvent exchange, chemical modification, emulsifier addition or mixing with water-borne resins, techniques which either limit the material’s application range or which are considered environmentally unfriendly. The unique approach presented here employed Res.-CBD as a surfactant-like agent supportive of the direct insertion of water-suspended NCC into an epoxy resin. The presented approach involves binding of Res.-CBD to NCC through its CBD domain and a chemical reaction between the resin epoxide groups and Res.-CBD amine moieties. The resulting bio-nano material shows a 50 % increase in the Young’s modulus and a 20 % decrease in the tan(δ), compared to pristine epoxy. This novel epoxy adhesive can be advantageous in applications where higher elasticity and Young’s modulus are required.     

Epoxy-urethane binders based on the blocked isocyanate Desmocap 11

The influence of the blocked isocyanate Desmocap 11 on the physico-mechanical characteristics of compositions based on the epoxy resin DER 330 and the cycloaliphatic amine hardener Polypox 488 was studied. A series of epoxy-urethane compositions that can be used as binders for coatings, adhesives, and sealants were obtained.     

ELASTOMERIC REACTIVE MICROGELS AS TOUGHENER FOR EPOXY ADHESIVES

Elastomerie reactive microgels were evaluated as toughener for epoxy adhesives. It turned out that elastomeric microgels can improve lap shear strength and peel strength greatly. The glass transition temperature of the resin matrix was not affected by the presence of dispersed mierogel particles, and thus the microgel-toughened adhesives have a good bond strength at elevated temperatures.