V.D. Athawale and A.V. Chamankar
Reports a comprehensive study of the effects of blend ratios (aliphatic alkyd and cyclohexanone formaldehyde resins) on coating properties. Solvent and drier systems used for…
Abstract
Reports a comprehensive study of the effects of blend ratios (aliphatic alkyd and cyclohexanone formaldehyde resins) on coating properties. Solvent and drier systems used for preparation of blends are also included in the present work. The properties studied were hardness, adhesion, flexibility, gloss, storage stability, impact resistance, chemical resistance and drying time. A blend ratio of 50:50 (w/w) aliphatic alkyd‐ketonic resins showed a significant improvement in adhesion, hardness, gloss, storage stability and acid resistance.
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V.D. Athawale and R.V. Nimbalkar
The purpose of this paper is to develop a volatile organic component‐free water‐based binder with improved coating properties from urethane‐alkyd acrylate by emulsion…
Abstract
Purpose
The purpose of this paper is to develop a volatile organic component‐free water‐based binder with improved coating properties from urethane‐alkyd acrylate by emulsion polymerisation.
Design/methodology/approach
Alkyd resin based on interesterification of sardine fish and linseed oil (50:50 w/w) was synthesised and reacted with isophorone diisocyanate to form urethane alkyd. The resultant urethane alkyd and acrylic monomers in different ratios were polymerised by emulsion polymerisation to form air‐drying water‐based binders and studied for physicochemical and other coating properties.
Findings
Urethane alkyd, co‐polymerised with acrylates by emulsion polymerisation process, can be used to prepare water‐based air‐drying binders with excellent coating and application performance. The increase in acrylate component in the system resulted in improvement of performance properties.
Research limitations/implications
In the present study, refined fish oil (FO) was obtained from sardine fish. Different FOs can be used to produce alkyd resin. Urethane alkyd and acrylic monomers in different ratios can be polymerised by emulsion polymerisation techniques.
Practical implications
The emulsion polymerisation is the most effective technique used to produce water‐based binders with excellent coating properties.
Originality/value
Water‐based binders can be widely used in exterior coatings and waterproofing of cement and roofs.
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V.D. Athawale and A.V. Chamanker
Reports on a comprehensive study of the effects of different driers on film properties of alkyd resin. The driers selected for study were calcium naphthanate and the octoates of…
Abstract
Reports on a comprehensive study of the effects of different driers on film properties of alkyd resin. The driers selected for study were calcium naphthanate and the octoates of cobalt, manganese, lead and zirconium. The properties studied were hardness, adhesion, flexibility, film formation, skinning tendency, water and acid resistance, viscosity and drying time. Concludes that driers not only dry coatings (paints, varnishes, resigns, inks) but have significant effect on the film properties. Infers that a combination of manganese, lead and zirconium can be used as the most promising drier system for better coating properties.
Tirthankar Jana and Tapan Kumar Dhar
The purpose of this paper is to develop an inorganic-organic hybrid emulsion polymer using grafted hyperbranched alkyd modified with nanometal oxide and to study the performance…
Abstract
Purpose
The purpose of this paper is to develop an inorganic-organic hybrid emulsion polymer using grafted hyperbranched alkyd modified with nanometal oxide and to study the performance of the developed hybrid emulsion in paint formulation with respect to antimicrobial and other properties.
Design/methodology/approach
A novel hybrid emulsion polymer was synthesized by grafting of vinyl acetate (VAM), vinyl ester of versatic acid (VeoVa 10) monomers onto hyperbranched alkyd resin and incorporation of nano magnesium oxide (MgO) into the hybrid resin matrix during dispersion of resin in water. Subsequently, paint was prepared by using this hybrid emulsion followed by a performance study.
Findings
The performance of nano MgO modified into VAM and VeoVa 10 grafted hyperbranched alkyd resulted in unique properties of coating especially antimicrobial activity.
Research limitations/implications
In the present study, soya fatty acid, polyol and di basic acid have been used to prepare hyperbranched alkyd by condensation polymerization. Monomers like VAM and VeoVa 10 used for grafting onto hyperbranched alkyd and nano MgO have been incorporated into hybrid resin matrix during emulsification of hybrid resin in water.
Practical implications
Grafting of VAM and VeoVa 10 onto hyperbranched alkyd along with in situ incorporation of nano MgO in resin matrix is an effective technique to achieve excellent coating properties.
Originality/value
Nano MgO modified VAM and VeoVa 10 grafted hyperbranched alkyd-based hybrid emulsion can be used as binder in water-based metal primer, direct to metal (DTM) coating as well as topcoat application. The developed system has antimicrobial properties as well as superior mechanical properties.
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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.
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Joseph Myoka James and Ismail W. R. Taifa
This research aimed at lowering the non-volatile matter (NVM) of long oil alkyd (LOA) resin to meet the resin requirements in producing Hi-gloss paints. The research also aimed to…
Abstract
Purpose
This research aimed at lowering the non-volatile matter (NVM) of long oil alkyd (LOA) resin to meet the resin requirements in producing Hi-gloss paints. The research also aimed to assist Hi-gloss paint manufacturers who require solid resin content below 70%.
Design/methodology/approach
The research utilised both the document review and experimental methods. The experimental method, which involved the blending process, was used in lowering the NVM of LOA resin, whereby eight experiments were conducted as reputations to obtain accurate data and results. A factorial design was used in the design of the experiment (DOE), where three factors were required to be evaluated: specific gravity, viscosity and NVM and two levels were required: weight of LOA and white spirit.
Findings
The NVM of LOA resin was successfully lowered, and different shades of paint were produced for reliability testing. The quality parameters of Hi-gloss paints that used the modified LOA were all found within the company's specifications compared to those with unmodified LOA, where some parameters were either above or below the specifications. However, all samples with the NVM of LOA used below 50% were found to be poor in terms of quality during the reliability testing. So, if the company had used the modified LOA resin in the production of Hi-gloss paints, it would have potentially saved 18,925.2 kg and 9,446.4 kg, respectively, of LOA just in producing Hi-gloss black and white paints only. Moreover, the cost of 1 kg of LOA is $2.3, which is equal to Tanzanian Shillings (Tshs) 5,290. The company would have potentially saved Tshs 100.114 million Tshs and Tshs 49.97 million Tshs in producing Hi-gloss black and white paints, respectively, making a total of Tshs 150.08 million per year. This was counted as a loss during that year because they did not use LOA resin with 50% NVM in production.
Research limitations/implications
This study focused on LOA resin used in producing Hi-gloss paints. The study also did not consider other categories of alkyd resins used in producing paints and varnishes e.g. epoxy resin and short and medium oil alkyd resins.
Originality/value
This is probably the first alkyd resin improvement study conducted using white spirit as Tanzania's main agent or material. The study utilised vegetable oils such as coconut, sunflower and tobacco seeds.
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Junrui Zhang, Guojun Jiang, Tianhao Huang, Jun Xie and Da Shi
The paper aims to provide a facile approach to the synthesis of polyurethane–silica nanocomposites by introducing self-made aqueous silica sols with different particle sizes into…
Abstract
Purpose
The paper aims to provide a facile approach to the synthesis of polyurethane–silica nanocomposites by introducing self-made aqueous silica sols with different particle sizes into polyurethane materials. This paper investigates the effects of the silica nanoparticles on the polyester polyol, as well as the physical properties and transmittance of the hybrid polyurethane coatings.
Design/methodology/approach
Colloidal silica particles of different sizes were obtained using a sol–gel process and were then embedded into polyester polyol by in-situ polymerization. These polyester polyol–silica resins were synthesized using an azeotrope process, using xylene to remove the water generated in the system and present in the dispersion medium for the colloidal silica. The polyester polyol–silica resins were further cured using isocyanate trimers to form polyurethane–silica hybrid films.
Findings
The paper observed that the viscosity of the polyester polyol–silica nanocomposite resins increased and their appearance changed from transparent to ivory white as the particle size of the added silica was increased. It was found that increasing the hydroxyl content of the silica improved the film transmittance in the visible light region. However, the transmittance decreased sharply once the diameter of the silica particles reached 100 nm.
Research limitations/implications
Because of the limitation of experimental conditions, some performances have not been tested. Therefore, researchers are encouraged to conduct further tests.
Practical implications
The paper provides a method of preparing hybrid polyurethane film by using silica; the results indicate that the introduction of nano-silica can improve the wear resistance and glass transition temperature of polyurethane coatings.
Originality/value
The results obtained in this study will be extremely useful to enhance the understanding of organic–inorganic hybrid materials.
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Vilas D. Athawale and Mona A. Kulkarni
The aim of this paper is to synthesise polyester/silica hybrid resins and their hybrid polyurethanes via in situ (IS) and blending (BL) methods and to evaluate the effect of…
Abstract
Purpose
The aim of this paper is to synthesise polyester/silica hybrid resins and their hybrid polyurethanes via in situ (IS) and blending (BL) methods and to evaluate the effect of preparation method, interaction type and silica content on the physico‐chemical and thermal properties of polyurethane/silica (PU/Silica) hybrid coatings.
Design/methodology/approach
Silica particle‐containing silica sol was prepared according to Stöber method using tetraethylorthosilicate as the precursor and then introduced into polyester matrix by in situ and direct blending method. The modified polyester/silica resin was further crosslinked with TMP‐TDI adduct to synthesise PU/Silica hybrid coatings and studied for thermo‐mechanical, physico‐chemical properties.
Findings
It was found IS polymerisation caused more polyester segments to chemically bond onto the surface of silica particles than BL process. Results also reveal that due to stronger interaction between silica particles and PU matrix, hybrid resins prepared by IS method confers better properties than BL method and exhibit optimal properties at the critical concentration of 8 wt% silica.
Research limitations/implications
In the present study, silica particles are used to modify properties of polyurethane resins. Many other countless combinations in terms of inorganic filler or organic matrices can be explored to obtain a wide range of interesting properties and applications.
Practical implications
The results obtained in this study will be extremely useful to enhance the understanding of this class of hybrid materials.
Originality/value
Hybrid organic‐inorganic networks offer a new area of material science that has extraordinary implications for developing novel materials that exhibit a diverse range of multi‐functional properties.
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Vilas D. Athawale and Mona A. Kulkarni
The purpose of this paper is to synthesise polyurethane/polyacrylate (PU/AC) core‐shell hybrid latex by emulsion polymerisation (PUA) and interpenetrating hybrid latex by…
Abstract
Purpose
The purpose of this paper is to synthesise polyurethane/polyacrylate (PU/AC) core‐shell hybrid latex by emulsion polymerisation (PUA) and interpenetrating hybrid latex by soap‐free emulsion polymerisation techniques latex interpenetrating polymer networks (LIPN) and to compare their physico‐chemical and thermo‐mechanical properties.
Design/methodology/approach
The interactions between the PU and AC components in hybrid coatings were studied with infrared spectroscopy. Mechanical properties were determined by measuring Shore A hardness, pencil hardness and flexibility of dried films. A particle size analyser and scanning electron microscopy were used to investigate the morphology of hybrid resins. Differential scanning calorimetry and thermogravimetric analysis were performed to investigate the thermal stability of polymeric films.
Findings
The core‐shell hybrids had better physico‐chemical and thermo‐mechanical properties than LIPN hybrids, attributing better interpenetration and entanglement between PU/AC in emulsion polymerisation.
Research limitations/implications
The syntheses of hybrid polymers can be extended for various combinations of acrylate monomers with crosslinkers, as well as for different types of PU ionomers.
Practical implications
The comparative study provides a simple and practical solution to improve performance characteristics of PU/AC hybrid coatings, which also proves to be cost effective.
Originality/value
The findings are of interest to those in surface coatings and adhesive applications.
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Tyrone De Alwis, Narayanage Jayantha Dewasiri and Kiran Sood
The goal of this study is to look into the connection between Sri Lanka’s fiscal deficit and inflation. Sri Lanka is currently experiencing one of its worst inflation crises in…
Abstract
The goal of this study is to look into the connection between Sri Lanka’s fiscal deficit and inflation. Sri Lanka is currently experiencing one of its worst inflation crises in its history, necessitating an investigation into how fiscal deficit affects inflation, as it has been experiencing an ever-increasing fiscal deficit for the last four decades. The quantitative methodology is employed in this study using annual data from 1977 to 2019 following the ARDL technique in the analysis. The findings showed that both in the long run and the near term, Sri Lanka’s fiscal deficit had a positive and significant link with inflation. The policymakers should increase the revenue through the taxes in order to bridge the fiscal deficit. As a developing country, it cannot afford to continue with the ever-increasing fiscal deficit which has become a burden to country. Also, it is the responsibility of each government to think carefully to reduce its massive expenditure which has become a common feature in the country for the last four decades. Cutting down government expenditure can improve the economic growth and well-being of the citizens too. The government should therefore concentrate on short-term investment programmes that will benefit the country while doing the same in the long run.