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Article

Tithi Maity, Bidhan Samanta, Ajit Banthia and Sudipta Dalai

The purpose of this paper is to find a new curing agent for diglycidyl ether of bisphenol A (DGEBA) resin and to check effectiveness of this new curing agent to obtain…

Abstract

Purpose

The purpose of this paper is to find a new curing agent for diglycidyl ether of bisphenol A (DGEBA) resin and to check effectiveness of this new curing agent to obtain toughness and chemical resistance of cured epoxy.

Design/methodology/approach

For this purpose, an investigation was carried out to synthesise, characterise and to study curing reaction of amine functional aniline acetaldehyde condensate (AFAAC) with DGEBA resin. AFAAC was first synthesised from the reaction of aniline and acetaldehyde in acid medium and characterised by FT‐IR, 1H‐NMR spectroscopic analyses, elemental analysis, concentration of primary and secondary amine analysis. Then equimolecular mixture of AFAAC and DGEBA was subjected to curing reaction and the reaction was followed by differential scanning calorimetry (DSC) analysis. The kinetic studies of this curing reaction, mechanical properties, dynamic mechanical analysis and thermogravimetric analysis (TGA) of cured epoxy were also reported.

Findings

The DSC analysis showed the complete exotherms of effective curing reaction indicating the efficiency of AFAAC as curing agent for DGEBA resin. The kinetic studies revealed that the curing reaction was first order. Mechanical properties reflect the better fracture properties of cured matrix and TGA showed that the cured matrixes were stable up to around 238°C.

Research limitations/implications

The curing agent AFAAC has been synthesised by using aniline and acetaldehyde. By changing amine and aldehyde, other curing agents could be synthesised and the curing efficiency of these for epoxy resin could also be studied.

Originality/value

The method for curing study of epoxy resin (DGEBA) is novel and relevant as the cured products have high‐performance applications in protective coatings, adhesives for most substrates.

Details

Pigment & Resin Technology, vol. 40 no. 5
Type: Research Article
ISSN: 0369-9420

Keywords

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Article

Tithi Maity and Bidhan Samanta

The purpose of this paper is to investigate the curing efficiency of amine functional aniline furfuraldehyde condensate (AFAFFC) for diglycidyl ether of bisphenol A…

Abstract

Purpose

The purpose of this paper is to investigate the curing efficiency of amine functional aniline furfuraldehyde condensate (AFAFFC) for diglycidyl ether of bisphenol A (DGEBA) resin to achieve toughness, chemical resistance, etc.

Design/methodology/approach

To study curing reaction, the curing agent AFAFFC is synthesised first from the reaction of aniline and furfuraldehyde in acid medium and characterised by Fourier transform infrared spectroscopic analysis, elemental analysis, concentration of primary and secondary amine analysis. Then, equimolecular mixture of AFAFFC and DGEBA is subjected to curing reaction and the reaction is followed by differential scanning calorimetry (DSC) analysis. The kinetic studies of this curing reaction, mechanical properties, dynamic mechanical analysis and thermogravimetric analysis (TGA) of cured epoxy are also reported.

Findings

The DSC analysis shows the complete exotherms of effective curing reaction indicating the efficiency of AFAFFC as curing agent for DGEBA resin. The kinetic studies reveal that the curing reaction is first order. Mechanical properties reflect the brittleness of cured matrix and TGA shows that the cured matrixes are stable up to around 240°C.

Research limitations/implications

The curing agent AFAFFC has been synthesised by using aniline and furfuraldehyde. By changing amine and aldehyde, other curing agents could be synthesised and the curing efficiency of these for epoxy resin could also be studied.

Originality/value

The method for curing study of epoxy resin (DGEBA) is novel and relevant as the cured products have high performance applications in protective coatings and adhesives for most substrates.

Details

Pigment & Resin Technology, vol. 38 no. 5
Type: Research Article
ISSN: 0369-9420

Keywords

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Article

Rafal Stanik, Albert Langkamp, Michael Müller, Maik Gude and Anna Boczkowska

Novel snap-cure polymers (SCPs), as matrix systems for high-performance fibre composite materials, provide high potential for manufacturing of component families with…

Abstract

Purpose

Novel snap-cure polymers (SCPs), as matrix systems for high-performance fibre composite materials, provide high potential for manufacturing of component families with small batch sizes and high variability. Especially, the processing of powdered SCP is associated with relatively simple and inexpensive tools. In addition, because of their curing behaviour, they allow short tooling times so that the production of small batch size components is possible in relatively short cycle times. To enable an efficient manufacturing process, an understanding of the curing process is necessary. An adjustment of the process parameters for a uniform design of the temperature field in the material during the manufacturing process is essential. The paper aims to discuss this issue.

Design/methodology/approach

For this, a powder SCP resin system was investigated under process-specific conditions. An experimental test approach for determination of various thermal and kinetic material properties was developed. For the adjustment of the process parameters and monitoring of the curing state during the manufacturing process, a kinetic material model was determined. In the end, the validation of the determined model was performed. For this, the temperature distribution under process- specific conditions was measured in order to monitor the curing state of the material.

Findings

The experimental investigation showed an uneven temperature field in the material, which leads to an inhomogeneous curing process. This can lead to residual stresses in the structure, which have a critical impact on the material properties.

Originality/value

The determined kinetic model allows a prediction of the curing reaction and adjustment of the process parameters which is essential, especially for thick-walled components with SCPs.

Details

International Journal of Structural Integrity, vol. 9 no. 6
Type: Research Article
ISSN: 1757-9864

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Article

Jing Lin, Wei Wang, Xiufang Wen, Zhi‐Qi Cai, Pihui Pi, Da‐feng Zheng, Jiang Cheng and Zhuoru Yang

The purpose of this paper is to study thermal stability, curing kinetics and physico‐chemical properties of polyurethanes systems for application in in‐mould decoration (IMD) ink.

Abstract

Purpose

The purpose of this paper is to study thermal stability, curing kinetics and physico‐chemical properties of polyurethanes systems for application in in‐mould decoration (IMD) ink.

Design/methodology/approach

The thermal stability of three Polyurethane (Pu) systems A, B, C were evaluated by thermogravimetric analysis (TGA). The kinetic parameters of the curing reaction of Pu system C were calculated using non‐isothermal curing kinetics analysis, including the activation energy Ea, the reaction rate constant K(T), the reaction order n, the initial curing temperature (Ti), the peak temperature (Tp), and the finishing temperature (Tf). Additionally, physico‐chemical properties were also evaluated such as flexibility, impact resistance, pencil hardness, adhesive attraction and solvent resistance.

Findings

TGA showed that thermal decomposition temperature T5 (5 wt.% weight loss), T10 (10 wt.% weight loss) and Tend (decomposition termination temperature) of Pu system C was 344°C, 363°C, and 489°C, respectively. T5, T10, Tend increased by 77°C, 61°C, 4°C, respectively, and the char yield at 600°C increased by 25.1 wt.% comparing with Pu system B. Curing kinetics analysis showed that Ea of Pu system C was 62.29 KJ/mol, 65.98 KJ/mol and 65.95 KJ/mol by Kissinger, Flynn‐Wall‐Ozawa and Ozawa method, respectively. The order of the curing reaction (n=0.90) demonstrated that it was a complex reaction. Moreover, Pu system C exhibited good physico‐chemical properties. The results showed that Pu system C was suitable to apply into IMD ink.

Research limitations/implications

The TGA analysis, curing kinetics analysis and evaluation of physico‐chemical properties provided a simple and practical solution to study suitable resins for IMD ink application.

Practical implications

IMD ink for heat transfer printing technology is highly efficient, relatively low cost, clean and environmentally safe. It has been widely applied into medical and pharmaceutical products, electronic devices, telecommunication equipment, computer parts, appliance panels, automotive parts, etc.

Originality/value

In this paper, the thermal stability and curing kinetics of Pu for IMD ink are reported for the first time. The paper gives very interesting and important information about thermal stability, curing kinetics and properties of Pu coating system for IMD ink application.

Details

Pigment & Resin Technology, vol. 41 no. 6
Type: Research Article
ISSN: 0369-9420

Keywords

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Article

T. Maity and B.C. Samanta

The purpose of this paper was to check effectiveness of amine functional chloroaniline acetaldehyde condensate (AFCAC) as a new curing agent for diglycidyl ether of…

Abstract

Purpose

The purpose of this paper was to check effectiveness of amine functional chloroaniline acetaldehyde condensate (AFCAC) as a new curing agent for diglycidyl ether of bisphenol A (DGEBA) resin. For this purpose, first AFCAC was synthesised, characterised and then curing reaction was carried out.

Design/methodology/approach

Equimolecular mixture of AFCAC and DGEBA was subjected to curing reaction, and the reaction was followed by differential scanning calorimetry (DSC) analysis. The kinetic studies of this curing reaction were also carried out from those DSC exotherms. The mechanical properties, dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) of cured epoxy were also reported.

Findings

DSC results reflected the effective first order curing reaction of AFCAC with epoxy resin. Mechanical properties reflected appreciable rigidity of AFCAC cured epoxy matrix and TGA showed that the cured epoxy networks were thermally stable up to around 297°C.

Research limitations/implications

The curing agent AFCAC was synthesised by using chloroaniline and acetaldehyde in acid medium. There are some limitations for this procedure. The synthetic procedure is pH dependent. So reaction cannot be done at any pH value. The reaction must also be carried out at room temperature without any heating. To obtain low molecular weight curing agent, chloroaniline and acetaldehyde cannot be taken in equimolecular ratio because the equimolecular mixture of them produces high molecular weight condensate. This was shown in our previous publication. Some implications are also there. By changing amine and aldehyde other curing agents could be synthesised and the curing efficiency of those for epoxy resin could also be studied.

Originality/value

Experimental results revealed the greater suitability of AFCAC as curing agent for DGEBA resin and novelty of AFCAC cured matrix in the field of protective coating, casting, adhesives, etc.

Details

Pigment & Resin Technology, vol. 44 no. 1
Type: Research Article
ISSN: 0369-9420

Keywords

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Article

T. Maity, B.C. Samanta, S. Dalai and A.K. Banthia

In order to study its cure response and to understand its kinetic behaviour, this paper seeks to examine how a multifunctional epoxy resin…

Abstract

Purpose

In order to study its cure response and to understand its kinetic behaviour, this paper seeks to examine how a multifunctional epoxy resin, N,4‐bis(4‐(bis(2‐oxiranylmethyl)amino)‐2‐chlorobenzyl)‐3‐chloro‐N‐(2‐oxiranylmethyl)benzenamine (BCCOMB), synthesised from amine functional chloroaniline formaldehyde condensate (AFCFC) and epichlorohydrine, is cured with AFCFC as curing agent.

Design/methodology/approach

For effective curing, AFCFC (12.5 phr, part per 100 resin) was added to BCCOMB resin and mixed thoroughly for 15 minutes. The clear viscous solution was then subjected to DSC analyses for kinetics study of the curing reaction.

Findings

The AFCFC was successfully utilised as curing agents for BCCOMB as the DSC curves show complete curing exotherm. The presence of oxirane group in the BCCOMB was able to react with active hydrogen atoms of amine. This led to conversion of liquid monomers of thermoset resin into three‐dimensional network.

Research limitations/implications

In the present discussion, the curing study of BCCOMB had been done using AFCFC as a curing agent. However, other curing agents, synthesised from other amine and aldehyde, could also be used to see whether they would be effective for curing study of BCCOMB.

Originality/value

The method for curing study of multifunctional epoxy resin (BCCOMB) was novel and the cured epoxy network could find numerous applications as surface coating and adhesive on to an intricate structure.

Details

Pigment & Resin Technology, vol. 36 no. 1
Type: Research Article
ISSN: 0369-9420

Keywords

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Article

Kalyan Ghosh, Patricia Garcia and Ernest Galgoci

Reports results from studies conducted on a polyfunctional amine adduct epoxy curing agent (EPI‐CURE DPC‐3293) as a means to design low temperature cure coatings. Through…

Abstract

Reports results from studies conducted on a polyfunctional amine adduct epoxy curing agent (EPI‐CURE DPC‐3293) as a means to design low temperature cure coatings. Through the judicious choice of epoxide resins and amine‐functional curing agents, relatively fast reaction rates and resistance to moisture and humidity are maintained under low‐temperature cure conditions, and that is evidenced by a good balance of performance properties of coating films. We have used differential scanning calorimetry (DSC) to study the extent of reaction as well as the glass transition temperatures (Tg). Electrochemical impedance spectroscopy (EIS) has been used to predict the barrier properties of coating films. These results are compared with epoxide resins cured with a phenalkamine curing agent to illustrate some of the unique advantages of using multifunctional amine adduct curing agents for the curing of epoxide resins under sub‐ambient cure conditions for a multitude of end‐use applications.

Details

Anti-Corrosion Methods and Materials, vol. 46 no. 2
Type: Research Article
ISSN: 0003-5599

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Article

D.T. Hsu, H.K. Kim, F.G. Shi, H.Y. Tong, S. Chungpaiboonpatana, C. Davidson and J.M. Adams

The curing reaction of a promising “no flow” flip chip underfill encapsulant is investigated by using a differential scanning calorimeter. It is found that the tested…

Abstract

The curing reaction of a promising “no flow” flip chip underfill encapsulant is investigated by using a differential scanning calorimeter. It is found that the tested underfill can reach complete cure within 20 minutes at various cure temperatures. It is also shown that this “no flow” underfill could fully cure within one minute at 160°C after being heated at 220°C for one minute, demonstrating that this “no flow” underfill can be completely cured during the solder reflow cycle. The reaction order and the rate constant are determined to describe the curing progress. It is shown that the autocatalytic effect dominates the reaction kinetics.

Details

Microelectronics International, vol. 17 no. 1
Type: Research Article
ISSN: 1356-5362

Keywords

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Article

Seng‐Neon Gan and Kim‐Teck Teo

Reports the effects of composition and curing temperature on the film properties of three water reducible enamels prepared from palm stearin alkyds. The properties studied…

Abstract

Reports the effects of composition and curing temperature on the film properties of three water reducible enamels prepared from palm stearin alkyds. The properties studied were hardness, flexibility, and adhesion. While all the formulations exhibit excellent adhesion, generally increasing the melamine content and curing temperature can increase the hardness but reduce the resistance to cracking and deformation of the coating. Applies Fourier transform infra‐red spectroscopy (FTIR) to the study of the curing reactions. Finds that FTIR is able to identify the predominant cross‐linking reactions.

Details

Pigment & Resin Technology, vol. 28 no. 5
Type: Research Article
ISSN: 0369-9420

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Article

C.A. Smith

Differential Scanning Calorimetry (DSC) is an ideal technique for characterising polymeric materials such as the epoxy resin in epoxy glass prepregs and laminates, the…

Abstract

Differential Scanning Calorimetry (DSC) is an ideal technique for characterising polymeric materials such as the epoxy resin in epoxy glass prepregs and laminates, the technique having evolved from the older qualitative method of Differential Thermal Analysis (DTA). In DSC the heat flow to or from the sample is measured as a function of temperature or time. Epoxy glass prepregs are used as the bonding/insulating layer in multilayer printed circuit boards. When a sample of the epoxy resin in prepreg is heated, the heat flow that results from the exothermic curing reaction is measured and used to calculate the enthalpy ΔH of the reaction. ΔH is related to the degree of B stage curing and the flow achievable in the laminating press. Methods are given for calculating ΔH and the differences found in two manufacturers' prepreg material are discussed. The effect of ageing on ΔH, which has been found to decrease with time and with the extent of cure, is examined at room temperature and under refrigeration. The difference in the ageing properties of the two prepregs is explained by reference to a plot of the degree of conversion with time. This plot also enables the curing time required in the lamination press and the shelf life of the prepreg at room temperature to be calculated. Monitoring the degree of cure of laminates and cured prepreg using the glass transition temperature of the resin is examined. Insufficient cure may lead to problems of resin smear in multilayer printed circuit boards. Thermochemical analysis is used as a routine quality control method in the Microcircuit Assembly Techniques Facility at Marconi Research Centre for testing incoming prepreg and laminates used in multilayer printed circuit board manufacture.

Details

Circuit World, vol. 12 no. 1
Type: Research Article
ISSN: 0305-6120

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