Search results

The epoxy resins need to be added with flame retardant to ensure safety in practical applications. There were a lot of highly toxic substances in the flame retardant used in the past, which caused greater harm to human body and the environment. Therefore, this study aims to propose a research on the synthesis of new phosphorous-containing flame retardant and the properties of flame retardant epoxy resins.

The flame retardant intermediate DOPO was synthesized using o-phenylphenol as the substrate. The intermediate was mixed with D4Vi under certain conditions to synthesize a new phosphorous-containing flame retardant. The flame retardant was added to the epoxy resins to prepare the flame retardant epoxy resins.

The experimental results show that the synthetic new phosphorous-containing flame retardant is far less harmful than the flame retardant used in the past and has extremely low toxicity, which is suitable for use in practical projects.

The new phosphorus-containing flame retardant synthesized by forms a more uniform and dense carbon layer in the combustion process, which well protects the underlying materials, thus improving the flame retardancy of epoxy resin materials. The harm of the new phosphorus-containing flame retardant is far less than that of ordinary flame retardant. The flame retardant used in the past has very low toxicity and is suitable for practical engineering.

This paper aims to discuss how acrylic resin influences the smoke generation of intumescent flame retardant coatings.

Thermal decomposition kinetics is used in this study to simulate the burning process. The thermal decomposition of acrylic resin can be identified in the intumescent coatings through the multi-peak fitting of derivative thermogravimetric (DTG) curves. The dormant influence of acrylic resin, combined with the smoke density, is calculated.

Multiple peaks fitting method of DTG curves helps estimate the decomposition process of acrylic resin in flame retardant coating. Combining DTG data with the smoking curve, smoking generation of acrylic resin during the combustion could be evaluated. The decomposition conversion rate of acrylic resin is 21.13 per cent. Acrylic resin generates 34.64 per cent of the total amount of smoke produced during the combustion of intumescent flame retardant coatings.

All the other intumescent flame retardant coating systems could be studied using the same approach as that used in this work to achieve an improved understanding of the smoke generation process during combustion.

The method developed here provided a simple and practical solution to analyse the decomposition and smoking generation of acrylic resin in the coating mixtures. It also can be used to analyse any thermal decomposition process of any mixed compounds.

The analysis method to evaluate resin’s smoking generation of coating’s total generation is novel, and it could be applied in all kinds of coatings and mixtures to estimate the smoking generation of one composition.

This paper aims to report on the synthesis and characterisation of new flame retardants and anticorrosive additives based on Schiff’s base compounds, which were added physically to organic coating.

Flame retardants are incorporated into polymeric materials either as additives or as reactive materials. Additive-type flame retardants are widely used by incorporating into polymeric materials by physical means. In this research, Schiff’s base (azomethine) compounds are added physically to alkyd paint as flame-retardant additives. Elemental analysis, infrared spectroscopy and proton nuclear magnetic resonance spectroscopy were used to characterise the structure of the prepared Schiff’s base compounds. Thermal gravimetric analysis was used to evaluate their thermal stability. Experimental coatings were manufactured on a laboratory scale, and then applied by brush on wood and steel panels.

Results of an oxygen index value indicated that alkyd paints containing Schiff’s base compounds as additives exhibit very good flame-retardant effects. Also the physical, mechanical and corrosion resistance properties were studied to evaluate the drawbacks of the additives. The additives did not affect the flexibility of the paint formula. The gloss and the impact strength were decreased by the additives, but the hardness, adhesion and corrosion resistance were significantly improved by these additives.

Alkyd resins are the most extensively used synthetic polymers in the coating industry. Nitrogen compounds are a small but rapidly growing group of flame retardants which are in the focus of public interest concerning environment-friendly flame retardants. So, the focus of this study is on Schiff’s base compounds as flame retardants and anticorrosive additives for alkyd resins to assess their applicability.

Schiff’s base compounds can be used as new additives in paint formulations to improve the flame-retardant and corrosion properties.

In recent years, there has been considerable interest in the nitrogen-based family of materials because they not only have a wide range of thermal and chemical stabilities, but can also provide improved thermal and flame-retardant properties to polymers. The present paper reports on the synthesis and characterisation of Schiff’s base compounds and their performance in alkyd resin coatings.

In order to find an appropriate method to synthesize a new high-efficiency flame retardant for epoxy resin.

In this work, a flame retardant with heterocyclic groups, HOMP, was acquired after removing the obstacle from triazines which was not readily soluble. The molecular structure, thermal and flame retardant properties were fully characterized and analyzed. Also, the mechanism was researched through multi-methodologies. As well, the authors evaluated the effects of HOMP on mechanical properties.

The results suggested that HOMP helped extinguish the combustion of specimens and could reach an LOI value of 29.2% and the V0 level in the UL-94 test with a phosphorus content of only 0.6wt%. With respect to the mechanism, HOMP was a gas-phase flame retardant and helped generate a thicker carbon protective coating. However, for the mechanical properties, the addition of HOMP enhanced the compressibility, while the tensile strength decreased significantly.

The approach not only simplified the operations but also obtained HOMP with excellent flame retardant properties.

The purpose of this paper is to present the mechanical and morphological characterization of new multifunctional carbon fibre-reinforced composites (CFRCs) that are able to overcome two of the main drawbacks of aeronautical composite materials: reduced electrical conductivity and poor flame resistance. Multiwall carbon nanotubes and glycidyl POSS (GPOSS) were used to simultaneously enhance electrical conductivity and flame resistance. The effect of these two combined components on the mechanical and morphological properties of the manufactured CFRCs was analysed.

This paper describes the mechanical test results obtained for interlaminar shear strength, three-point bending, and tensile and fracture toughness in mode I tests. Carbon fibre-reinforced epoxy resin plates were manufactured in two series with blank resin and CNT+flame retardant GPOSS-enhanced resin.

The mechanical properties were decreased by no more than 10 per cent by combined influence of CNTs and GPOSS. Agglomerates of CNTs were observed using scanning electron microscopy. The agglomerates were large enough to be visible to the naked eye as black spots on the delaminated fracture surface. The decrease of the mechanical properties could be caused by these agglomerates or by a changed fibre volume content that was affected by the difficult infusion procedure due to high resin viscosity.

If we consider the benefit of CNTs as a nanofiller to increase electrical conductivity and the GPOSS as a component to increase the flame resistance of the resin, the decrease of strength seems to be insignificant.

In order to meet international standards, PCB base materials have to be flame‐retardant according to the UL 94V specification. Up to now this has been achieved with FR‐4 materials by using brominated aromatic components. Unfortunately, in the case of fire or smouldering, these materials evolve highly corrosive and, under unfavourable conditions, even highly toxic decomposition products. In the search for flame retardancy without the use of bromine, the effect of different structural elements on the burning behaviour of cured resins has been investigated. As a result of these investigations an epoxy resin was developed which contains tailor‐made N‐ and P‐ containing constituents that form flame‐retardant structures during processing and curing of the material. The new material meets all requirements for printed circuit boards and can be processed without any need to modify established technologies. Analytical and ecotoxicological investigations of the combustion products of the new material show that they are comparable with those of wood from the beech tree. The project has already produced first samples of a PCB assembly that successfully passed all functional tests.

Cyclohexanone–formaldehyde resin (CFR) was in situ modified with isocyanuric acid (ICA) in the presence of hydrochloric acid or p-toluenesulfonic acid by condensation polymerization. The purpose of this study is to produce isocyanuric acid-modified ketonic resins that have higher melting and decomposition temperature, and to use the produced resin in the production of fire-retardant polyurethane.

Two methods were used for in situ preparation of ICA-modified CFR in the presence of an acid catalyst. Method I: cyclohexanone, paraformaldehyde and ICA were mixed, and then an acid catalyst was added to form the modified CFR. Method II: ICA and formalin were mixed to produce N, N, N-trihydroxymethyl isocyanurate, and then water was removed under vacuum. The produced N, N, N-trihydroxymethyl isocyanurate solution was mixed with cyclohexanone and paraformaldehyde, then an acid catalyst was slowly added to this mixture to obtain ICA-modified CFR.

CFR was prepared in the presence of an acid catalyst. The product, CFR, has a dark red colour. The resulting resins have similar physical properties with the resin prepared in the presence of a basic catalyst. The solubility of ICA-modified CFR is much different than CFR in organic solvents.

This study focuses on obtaining an ICA-modified ketonic resin. Cyanuric acid has the form of an enolic structure under a basic condition; therefore, it cannot give a product with formaldehyde under basic conditions. The modification experiments were carried out in acidic conditions.

This study provides technical information for in situ modification of ketonic resin in the presence of acid catalysts. The resins may also promote the adhesive strength of the coating and provide corrosion inhibition on metal surfaces for a coating. The modified resins may also be used in the field of fire-retardant polyurethane applications.

These resins may be used for the preparation of non-toxic fire-retardant polyurethane foam. Polyurethane containing ICA-modified resin may exhibit better fire-retardant performance because of the incorporation of ICA molecule into the polyurethane structure.

ICA-modified CFRs have been synthesized in the presence of an acid catalyst, and the ICA-modified resin was used to produce fire-retardant polyurethane.

The purpose of this paper is to present a latest update on halogen‐free base materials that are lead‐free compatible and have enhanced electrical properties.

Numerous halogen‐free flame retardants are screened in laboratory conditions for a wide arrange of properties. Once suitable candidates are found, they are compounded and processed into copper‐clad laminates and a wide variety of properties are tested.

Several formulations are found that are lead‐free compatible and that has enhanced electrical properties. Surprisingly, some thermal properties are found to be superior to traditionally halogenated laminates.

The research here only presents the halogen‐free properties of a bare, unpopulated printed wiring board with no build up of inner layers and devoid of solder mask. Further work needs to be done on full circuit assemblies to properly evaluate the impact of removing halogens from interconnecting packages.

The paper details the material property differences between various halogen‐free materials as compared to halogenated materials. A method to model composite properties is also discussed.

Examines the fourteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.