R. Sandford and A. Gindre
For more than 30 years Goodyear has been a leader in solvent paint resin technology for the building sector, with the Pliolite range of resins. Today however, the paint industry…
Abstract
For more than 30 years Goodyear has been a leader in solvent paint resin technology for the building sector, with the Pliolite range of resins. Today however, the paint industry is moving into a new era of social awareness of the environment. Goodyear, determined to maintain their lead by bringing new technology to the industry, is now in a position to announce the first of the new Plioway range of acrylic copolymer resins soluble in low odour, “aromatic free” solvents. The principal idea behind the development program of Plioway resins is to obtain for the first time solubility in non‐aggressive, low toxicity solvents while maintaining the very highest level of performance associated with solvent paint systems.
This paper aims to a newly designed photoresponsive four-armed graft copolymer was synthesised and characterised. The synthesised polymer contains photochemical group and a…
Abstract
Purpose
This paper aims to a newly designed photoresponsive four-armed graft copolymer was synthesised and characterised. The synthesised polymer contains photochemical group and a greater part of the cross-linkable functional group which is not affected by short wavelength when subject to under ultraviolet (UV) irradiation in film status.
Design/methodology/approach
The four-armed macroinitiator was prepared by reacting diethanol amine with poly [methyl-2-chloro-4-{7-(chloroacetyl) oxy]-2-oxo-2H-chromen-4-yl}-2-methylbutanoate] and acylating the product with chloroacetyl chloride. A grafting reaction with n-butyl methacrylate was carried out in the presence of the four-armed macroinitiator and the catalyst CuBr/2, 2′-bipyridyne at 90°C. All of the synthesised polymers were structurally characterised by Fourier transform infrared spectroscopy (FT-IR) and Hydrogen-1 Nuclear Magnetic Resonance (1H-NMR) spectra. Gel permeation chromatography was used to obtain the molecular weights of polymer.
Findings
1H-NMR, FT-IR and ultraviolet-visible (UV-Vis) spectroscopy demonstrated that the four-armed macroinitiator and the graft copolymer was successfully synthesised. The end-functionalised poly(methyl methacrylate) with 7-hydroxyl-4-chloromethyl coumarin was irradiated at the wavelength larger than 300 nm to create the cyclobutane ring in between the 7-hydroxyl-4-chloro methyl coumarin unities. To characterise the polymer and show the transformation of coumarin unities into photodimers, 1H-NMR, FT-IR and UV-Vis spectroscopy were used.
Research limitations/implications
Graft copolymer containing coumarin has involves photocrosslinkable functional group, in which reactive functional group has attracted great interest from both industrial and academic fields. Their synthesis provides the opportunity for a compatible modification of the graft copolymer structure to develop adapted macromolecules for a range of end practices.
Practical implications
A photoresponsive graft copolymer can have a role in an active area of polymer chemistry research due to its uses in the areas of photolithography, liquid crystal, non-linear optical materials, laser dyes, fluorescence materials and future microelectronics.
Originality/value
Graft copolymers containing a photocrosslinkable functional group, and a star polymer may be prepared using the method described in this paper and then used in technological applications. The method discussed here also allows photoinduced reversible self-healing in solid polymers.
Details
Keywords
Shamsher Singh, Abhas Jain, Prachi Chaudhary, Rishabh Gupta and Harlal Singh Mali
This paper aims to investigate the dimensional accuracy and surface roughness of printed masked stereolithography (m-SLA) parts. The fabricated specimens of photosensitive polymer…
Abstract
Purpose
This paper aims to investigate the dimensional accuracy and surface roughness of printed masked stereolithography (m-SLA) parts. The fabricated specimens of photosensitive polymer resin have complex shapes and various features. The influence of four process parameters of m-SLA, including layer height, exposure time, light-off delay and print orientation, is studied on response characteristics.
Design/methodology/approach
The Box–Behnken design of response surface methodology is used to examine the effect of process parameters on the shrinkage of various geometrical dimensions like diameter, length, width, and height of different features in a complex shape. Additionally, a multi-response optimization has been carried out using the desirability function to minimize the surface roughness and printing time and maximize the dimensional accuracy.
Findings
The layer height and print orientation influence the surface roughness of parts. An increase in layer height results in increased surface roughness, and the orientation parallel to the z-axis of the machine gives the highest surface roughness. The dimensional accuracy of m-SLA parts is influenced by layer height, exposure time, and print orientation. Although not significant in dimensional accuracy and surface roughness, the light-off delay can affect printing time apart from other parameters like layer height and print orientation.
Originality/value
The effect of layer height and print orientation on dimensional accuracy, printing time, and surface roughness is investigated by researchers using simple shapes in other vat photopolymerization techniques. The present work is focused on studying the effect of these parameters and additional parameters like light-off delay in complicated geometrical parts in m-SLA.
Details
Keywords
Mir-Hassan Moosavy and Nassim Roostaee
The composition and properties of milk are considerably important for dairy farmers, manufacturers and consumers. Despite the significant role of bovine milk in Iranian dairy…
Abstract
Purpose
The composition and properties of milk are considerably important for dairy farmers, manufacturers and consumers. Despite the significant role of bovine milk in Iranian dairy products, there is little information about the effect of production season and location on the physicochemical properties of pasteurized milk as a final product. The purpose of this study was to investigate the effects of seasonal, geographical and product brand variations on the chemical components and physical properties of Iranian pasteurized bovine milk.
Design/methodology/approach
A total of 400 samples of pasteurized milk were obtained during a 12-month period, from April 2014 to March 2015, using random sampling. Chemical components (protein, fat, lactose, dry matter and solids-not-fat) and physical properties (freezing point, extraneous water content, titratable acidity, density and pH) of the collected samples were analyzed. A one-way ANOVA was used to perform the statistical analysis of data, and results were presented as the mean ± standard deviation.
Findings
It was found that the biochemical constituents and physical properties of pasteurized milk samples were linked to seasonal and geographical variation parameters. The milk sampled during spring and summer contained significantly less fat, protein and solids-not-fat (p < 0.05) than samples in autumn and winter. Also, samples in spring had a significantly higher (p < 0.05) extraneous water (0.8 per cent) compared to milk sampled in winter (−0.4 per cent). Samples in Maragheh and Mianeh contained the highest level of fat (2.82 per cent) and protein (3.09 per cent) content in the province. The sampled milk from the south (Mianeh and Hashtrud) and the northwest (Marand) had also significantly higher (p < 0.01) freezing points than the other areas. No significant differences (p > 0.01) were found in physicochemical properties in different product brands of the milk samples.
Originality/value
Seasonal and geographical parameters are crucial factors in the diversity of physicochemical parameters of commercial pasteurized milk. In this study, unlike the other studies, differences in milk product brand were not significant. Further research will be needed to assess other factors such as the effect of management practices and feeding strategies on farms.
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Keywords
Harshit K. Dave, Ravi Teja Karumuri, Ashish R. Prajapati and Shilpesh R. Rajpurohit
Liquid crystal display (LCD)-based stereolithography (SLA) technique has been used in drug delivery and fabrication of microfluidic devices and piezoelectric materials. It is an…
Abstract
Purpose
Liquid crystal display (LCD)-based stereolithography (SLA) technique has been used in drug delivery and fabrication of microfluidic devices and piezoelectric materials. It is an additive manufacturing technique where an LCD source has been used as a mask to project the image onto the tank filled with photo curable resin. This resin, when interacted with light, becomes solid. However, critical information regarding the energy absorption during the compression analysis of different components three-dimensional (3D) printed by SLA process is still limited. Therefore, this study aims to investigate the effect of different process parameters on the compressive properties.
Design/methodology/approach
In the present study, the influence of layer thickness, infill density and build orientation on the compression properties is investigated. Four infill densities, that is, 20%, 40%, 60% and 80%; five-layer thicknesses, that is, 50 µm, 75 µm, 100 µm, 150 µm and 200 µm; and two different orientations, that is, YXZ and ZXY, have been selected for this study.
Findings
It is observed that the samples printed with acrylonitrile butadiene styrene (ABS) absorbed higher energy than the flexible polyurethane (FPU). Higher infill density and sample oriented on ZXY absorbed higher energy than sample printed on YXZ orientation, in both the ABS and FPU materials. Parts printed with 80% infill density and 200 µm layer thickness resulted into maximum energy for both the materials.
Originality/value
In this study, two different types of materials are used for the compression analysis using LCD-SLA-based 3D printer. Specific energy absorbed by the samples during compression testing is measured to compare the influence of parameters. The investigation of infill parameters particularly the infill density is very limited for the SLA-based 3D printing process. Also, the results of this study provide a database to select the print parameters to obtain the required properties. The results also compare the specific energy for hard and flexible material for the same combination of the process parameters.