Search results
1 – 10 of over 1000Guanidine stearate will function as a lubricant for melamine/formaldehyde resins (and guanamine/formaldehyde resins), and glyceryl monostearate can improve the mechanical…
Abstract
Guanidine stearate will function as a lubricant for melamine/formaldehyde resins (and guanamine/formaldehyde resins), and glyceryl monostearate can improve the mechanical properties of the former. Laurie acid can be applied to the production of high grade baking enemel resins in combination with melamine. Stearic acid can be used in the manufacture of melamine resins, e.g. by reaction with formaldehyde and butanol, to give resins for lacquers, and to yield moulding resins. Sodium myristate is usable as a chain transfer agent in the emulsion polymerisation of methyl methacrylate. Copolymerisation of methacrolein dibutyrate and methyl methacrylate has given resins that can be moulded or used in varnishes, and reaction products of stearic acid with methacrylic acid and neodymium oxide has given transparent optical resins. Cellulose laurate can produce extensibilities of nitrocellulose of the order of 100%, and cetyl acetate can act similarly in film, having little tendency to yellowing, but it has also little stability to exterior exposure. When ethylene glycol monmethyl ether acetyl ricinoleate is incorporated into nitrocellulose as a plasticizer, it gives films that are clear, tough and flexible. Stearic acid can act as a stabilizer for nitrocellulose. Lauryl phosphate has been applied as a catalyst in the modification of olefinic petroleum results, by reaction with acrylic resins, and distearyl pentaerythritol diphosphite can function as a heat stabilizer in petroleum resins.
The most important component of a coating is the resin: all other components simply modify the resin. Solvents affect the flow, pigments give decorative effects and aid economy;…
Abstract
The most important component of a coating is the resin: all other components simply modify the resin. Solvents affect the flow, pigments give decorative effects and aid economy; the physical and chemical properties of the resins used are the principal differences in various paint systems
Kaiyan Yang, Xiaowu Gong, Lanli Bai, Yun Zhang and Na Zhou
This study aims to prepare a low-formaldehyde and environmentally friendly glucose-lignin-based phenolic resin.
Abstract
Purpose
This study aims to prepare a low-formaldehyde and environmentally friendly glucose-lignin-based phenolic resin.
Design/methodology/approach
The authors directly used lignin to substitute formaldehyde to prepare lignin-based phenolic resin (LPF) with urea as formaldehyde absorbent. To improve the performance of the adhesive, the biobased glucose was introduced and the modified glucose-LPF (GLPF) was obtained.
Findings
The results showed that when the replacing amount of lignin to formaldehyde reached 15 Wt.%, the physical properties of the prepared LPF met the Chinese national standard, and the bonding strength increased by 21.9%, from 0.75 to 0.96 MPa, compared with PF. The addition of glucose boost the performance of wood adhesive, for example, the free phenol content of the obtained GLPF was significantly reduced by 79.11%, from 5.60% to 1.17%, the bonding strength (1.19 MPa) of GLPF increased by 19.3% in comparison to LPF and the curing temperature of GLPF decreased by 13.08%.
Practical implications
The low-formaldehyde and environmentally friendly GLPF has higher bonding strength and lower curing temperature, which is profitable to industrial application.
Social implications
The prepared GLPF has lower free formaldehyde and formaldehyde emission, which is cost-effective and beneficial to human health.
Originality/value
The joint work of lignin and glucose provides the wood adhesive with increased bonding strength, decreased free phenol content and reduced curing temperature.
Details
Keywords
Appala Naidu Uttaravalli and Srikanta Dinda
The purpose of the present study is first to develop a hydroxyl-functionalized ketonic resin for coating applications and to establish a standard characterization protocol;…
Abstract
Purpose
The purpose of the present study is first to develop a hydroxyl-functionalized ketonic resin for coating applications and to establish a standard characterization protocol; second, to quantify the effects of various operating parameters on resin properties and to develop mathematical models to predict the product properties; and third, to carry out the compatibility study between the in-house developed resins and commercially available resins.
Design/methodology/approach
Self-polymerization reactions were conducted in a batch reactor. Effects of reaction time, temperature, catalyst concentration and reactor pressure on product properties have been studied. Hydroxyl value, iodine value, solubility, rheology, gel permeation chromatography (GPC), thermogravimetric analysis (TGA), scanning electron microscope (SEM) and the X-ray diffraction (XRD) analysis were carried out to characterize the product properties. Mark–Houwink correlation was used to predict molecular weight of the resins.
Findings
The study shows that hydroxyl value and softening temperature (ST) of the product increased with the increase of reaction temperature, duration of reaction and alkali concentration. However, the solubility value of the resins decreased with the increase of temperature, time and alkali concentration. Regression models were developed to predict the optimum conditions for obtaining a desired quality of resin. The number-average molecular weight of the developed resins was in the range of 450-1150. The products are thermally stable up to around 200°C, and adequately soluble in many commercial solvents.
Research limitations/implications
The ketonic resin can be used as a substitute of phenolic resins which are prepared from more hazardous materials monomers such as phenolic and aldehyde compounds.
Practical implications
The resin can be used as a substitute of more hazardous materials such as phenolic and aldehyde compounds.
Originality/value
This paper details the synthesis of ketonic resin from cyclohexanone and its compatibility. It also investigates the optimization of operating parameters to obtain a desire product.
Details
Keywords
Ssuwei Chen, Jeremy Murphy, Jason Herlehy, David L. Bourell and Kristin L. Wood
This paper aims to present a new fabrication method for fuel cell current collectors. Demonstration of its usefulness and discussion of its impact on current collector design and…
Abstract
Purpose
This paper aims to present a new fabrication method for fuel cell current collectors. Demonstration of its usefulness and discussion of its impact on current collector design and performance are also given.
Design/methodology/approach
The selective laser sintering (SLS) technique is used to create green parts followed by a high temperature curing process and pressureless infiltration treatment to meet basic part design requirements.
Findings
A material system and process satisfying both manufacturing constraints and product property requirements can be used for fabrication of current collectors via SLS. Relative particle size and composition of the constituents play an important role in successful manufacture of the plates. Strategies to improve electrical conductivity are also discussed.
Originality/value
A new manufacturing method has been developed for the construction of fuel cell current collectors that could generate opportunities for performance enhancement and fuel cell application by eliminating the constraints imposed by traditional fabrication processes.
Details
Keywords
This article deals with corrosion‐resisting floor surfaces, provided over suitable load‐bearing bases, to withstand the corrosive action of chemicals to which they will be…
Abstract
This article deals with corrosion‐resisting floor surfaces, provided over suitable load‐bearing bases, to withstand the corrosive action of chemicals to which they will be subjected. When considering suitable acid‐ and chemical‐resistant floors, apart from corrosion, the type of traffic, maintenance, ease of renewal, amount of solution present on the floor and personnel reactions should be taken into account also. When designing new floors, attention must be paid to possible vibrations resulting from traffic or nearby machinery, possible settling of the floor, and the live and dead loads it will be subject to.
Kaushik Alayavalli and David L. Bourell
The purpose of this paper is to produce electrically conductive, fluid impermeable graphite bipolar plates for a direct methanol fuel cell, using indirect selective laser…
Abstract
Purpose
The purpose of this paper is to produce electrically conductive, fluid impermeable graphite bipolar plates for a direct methanol fuel cell, using indirect selective laser sintering (SLS) and suitable post processing techniques.
Design/methodology/approach
Bipolar plates are made by the indirect SLS of graphite powder and phenolic resin mixture. The phenolic resin binder is then burnt off at a high temperature in a vacuum furnace to produce a 100 per cent carbon part. This brown part is then infiltrated using a low‐viscosity (∼5‐10 cps) cyanoacrylate to seal up the open pores, rendering the plates fluid impermeable.
Findings
It has been found that the electrical conductivity increases significantly (> 220 S/cm) with a corresponding increase in pyrolyzing temperature which correlates well with literature on the carbonization of phenol formaldehyde resins. The cyanoacrylate infiltrated parts tested under fluid pressure demonstrated no leakage through the plate, indicating full closure of open porosity.
Originality/value
This work demonstrates the capability of the SLS process to produce working bipolar plates with complex flow field designs that can be tested to verify its efficacy in a working fuel cell, thereby saving time and cost in machining natural graphite.
Details
Keywords
Polyvinyl acetal resins have grown in use steadily over the past two decades. Pioneered by Monsanto under the trademarks Butvar® (polyvinyl butyral) and Formvar® (polyvinyl…
Abstract
Polyvinyl acetal resins have grown in use steadily over the past two decades. Pioneered by Monsanto under the trademarks Butvar® (polyvinyl butyral) and Formvar® (polyvinyl formal), the resins have a combination of properties making them ideal for applications in many different fields.
Harun Yanar, Hasan Huseyin Ayar, Muhammet Demirtas and Gencaga Purcek
This paper aims to investigate the effect of straight phenolic resin content on the fade behavior, frictions and wear characteristics of pre-determined brake pad composite matrix…
Abstract
Purpose
This paper aims to investigate the effect of straight phenolic resin content on the fade behavior, frictions and wear characteristics of pre-determined brake pad composite matrix having specific amount of barite (BaSO4), rock wool, Kevlar, graphite and magnetite.
Design/methodology/approach
Different amount of resin ranging between 16 and 20 wt. per cent were added by changing only the filler (barite) content of composite matrix. Subsequently, friction and wear behavior of the composite samples were analyzed using a special pin-on-disc type test system developed for brake pad sample. The worn surfaces were investigated by SEM and three-dimensional (3D) surface profilometer.
Findings
The average coefficient of friction (CoF) of composite samples and temperature of the disc surface showed a linear increase with decreasing the resin content. The sample having 20 wt. per cent resin showed the minimum wear rate with smooth worn surface. But the amount of fade is quite high in that sample. Decreasing resin content decreased the fade formation, and the composite with 16 per cent resin brought about the minimum fade formation. As the fade formation is unwanted in brake pad applications, the composite with 16 wt. per cent resin was proposed as the most appropriate one considering the performance parameters related to friction and wear.
Originality/value
This paper optimizes the resin content of composite brake pad materials to achieve the best combination of its tribo-performance and mechanical properties and provides valuable information for scientists and engineers working in that area.
Details
Keywords
ALL ‘plastics’ are generally divided into two groups: the ‘thermoplastics’, which are formed by heating, can be re‐heated after forming, and re‐formed almost ad lib, such as…
Abstract
ALL ‘plastics’ are generally divided into two groups: the ‘thermoplastics’, which are formed by heating, can be re‐heated after forming, and re‐formed almost ad lib, such as celluloid, xylonite, rhodoid, cellophane, and perspex; and the ‘thermosetting plastics’, which are also formed by heating but cannot yet be re‐formed by the application of heat or any other means, probably the best‐known example of which is the thermosetting variety of bakelite.