scholarly journals Comparative Study of Aromatic and Cycloaliphatic Isocyanate Effects on Physico-Chemical Properties of Bio-Based Polyurethane Acrylate Coatings

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1494
Author(s):  
Nurul Huda Mudri ◽  
Luqman Chuah Abdullah ◽  
Min Min Aung ◽  
Mek Zah Salleh ◽  
Dayang Radiah Awang Biak ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Uv Curing ◽  
Toluene Diisocyanate ◽  
Gravimetric Analysis ◽  
Jatropha Oil ◽  
Clear Coat ◽  
Polyurethane Acrylate ◽  
Physico Chemical ◽  
Degradation Pattern ◽  
Coating Formulation

Crude jatropha oil (JO) was modified to form jatropha oil-based polyol (JOL) via two steps in a chemical reaction known as epoxidation and hydroxylation. JOL was then reacted with isocyanates to produce JO-based polyurethane resin. In this study, two types of isocyanates, 2,4-toluene diisocyanate (2,4-TDI) and isophorone diisocyanate (IPDI) were introduced to produce JPUA-TDI and JPUA-IPDI respectively. 2,4-TDI is categorised as an aromatic isocyanate whilst IPDI is known as a cycloaliphatic isocyanate. Both JPUA-TDI and JPUA-IPDI were then end-capped by the acrylate functional group of 2-hydroxyethyl methacrylate (HEMA). The effects of that isocyanate structure were investigated for their physico, chemical and thermal properties. The changes of the functional groups during each synthesis step were monitored by FTIR analysis. The appearance of urethane peaks was observed at 1532 cm−1, 1718 cm−1 and 3369 cm−1 while acrylate peaks were detected at 815 cm−1 and 1663 cm−1 indicating that JPUA was successfully synthesised. It was found that the molar mass of JPUA-TDI was doubled compared to JPUA-IPDI. Each resin showed a similar degradation pattern analysed by thermal gravimetric analysis (TGA). For the mechanical properties, the JPUA-IPDI-based coating formulation exhibited a higher hardness value but poor adhesion compared to the JPUA-TDI-based coating formulation. Both types of jatropha-based polyurethane acrylate may potentially be used in an ultraviolet (UV) curing system specifically for clear coat surface applications to replace dependency on petroleum-based chemicals.

scholarly journals Radiation-induced Grafting of Styrene onto Polyethylene Films for Preparation of Cation Exchange Membranes: Effect of Crosslinking+

2017 ◽  
Vol 2 (1) ◽  
Author(s):  
M. M. Nasef ◽  
H. Saidi ◽  
A. H. Yahaya
Keyword(s):  
Cation Exchange ◽  
Chemical Properties ◽  
Exchange Capacity ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Swelling Properties ◽  
Ion Exchange Capacity ◽  
Physico Chemical ◽  
Styrene Divinylbenzene ◽  
Radiation Induced

Crosslinked cation exchange membranes bearing sulfonic acid groups (PE-g-PSSA/DVB) were prepared by radiationinduced grafting of styrene/divinylbenzene (DVB) mixtures onto low density polyethylene (PE) films followed by sulfonation reactions. The effect of addition of DVB (2 and 4%) on the grafting behavior and the physico-chemical properties of the membranes such as ion exchange capacity, swelling and ionic conductivity were evaluated incorrelation with grafting yield (Y%). The structural and thermal properties of the membranes were also studied using differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA), respectively. Crosslinking with DVB was found to considerably affect the properties of the membranes in a way that reduces the swelling properties and enhances the chemical stability. The ion conductivity of the crosslinked membranes recorded a level of 10–2 S/cm at sufficient grafting yield (28%) despite the reduction caused by the formation of crosslinking structure. The results of this work suggest that membranes prepared in this study are potential alternatives for various electrochemical applications.

Characterization of Spent Catalysts during Hydrodemetallization of Atmosphere Residue

2011 ◽  
Vol 236-238 ◽  
pp. 538-542
Author(s):  
Yong Jun Liu
Keyword(s):  
Chemical Properties ◽  
Analytical Techniques ◽  
Resonance Spectroscopy ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Physico Chemical ◽  
Spent Catalysts ◽  
C Nmr

The deactivation behavior of industrial hydrodemetallization catalysts was investigated in the presented work. The main objective of the study is to contribute to a better understanding of the nature of the coke and metal deposition on the used catalysts by applying chemical analysis and various advanced analytical techniques, such as X-ray diffraction analysis (XRD), thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), and solid-state carbon-13 nuclear magnetic resonance spectroscopy (13C NMR). The results are discussed scientifically based on the physico–chemical properties of origin and used catalysts.

Research on the Modification of Waterborne UV-Curable Polyurethane Acrylate

2013 ◽  
Vol 864-867 ◽  
pp. 698-701
Author(s):  
Jian Yun He ◽  
Yong Liu ◽  
Li Chen He ◽  
Qiang Wang
Keyword(s):  
Uv Curing ◽  
Acrylic Resin ◽  
Ethyl Acrylate ◽  
Toluene Diisocyanate ◽  
Polypropylene Glycol ◽  
Hyperbranched Polyester ◽  
Uv Curable ◽  
Polyurethane Acrylate ◽  
Overall Performance ◽  
Influent Factors

In this study, waterborne UV-curable polyurethane acrylic resin was synthesized using polypropylene glycol, toluene diisocyanate, dimethylol propionic acid and hydroxyl ethyl acrylate, and modified by hyperbranched polyester acrylate. The influent factors on hydrophilic properties and UV curing speed of the resin were discussed, and the modified resin has compared with that of unmodified resin. Results showed that the overall performance and UV curing speed of the resin modified by hyperbranched polyester was greatly enhanced, the hydrophilic property of the resin was proportional to hydrophilic group content.

Study on Photopolymerization Performance of Waterborne UV Cured Ink

2010 ◽  
Vol 174 ◽  
pp. 401-404
Author(s):  
Rui Xin Xu ◽  
Guang Xue Chen
Keyword(s):  
Infrared Spectroscopy ◽  
Uv Curing ◽  
Yellow Pigment ◽  
Water Soluble ◽  
Pigment Content ◽  
Toluene Diisocyanate ◽  
Polyurethane Acrylate ◽  
Optimum Content ◽  
Drying Technology ◽  
Dihydroxy Compound

The anion UV-curing water soluble prepolymer was synthesized with toluene diisocyanate, dihydroxy compound, dihydroxyalkyl carboxylic acid and polyurethane acrylate. The structure of the prepolymer was characterized by infrared spectroscopy. The effect of different photoinitiators, pigment content, drying technology on the curing speed of ink was also researched. The results shown that the photoinitiator system 819DW and MBF was best matched with the yellow pigment, cyan pigment and black pigment, the optimum content of the pigment was about 10 percent, 10 percent and 11 percent. The photoinitiator system 819DW and 500 was best matched with the magenta pigment, the optimum content of the pigment was about 10 percent．Under the conditions of this experiment, the best pigment content of the yellow, magenta, cyan, black was about 6 percent, 7 percent, 6 percent and 7 percent. The curing rate without pre-drying increased.

Surface decontamination in fuel manufacture plants by chelating solution of nanoparticles

2017 ◽  
Vol 0 (0) ◽  
Author(s):  
T. M. Morsi ◽  
Ahmed M. Elbarbary ◽  
Mohamed M. Ghobashy ◽  
Sameh H. Othman
Keyword(s):  
Cyano Group ◽  
Chemical Properties ◽  
Germanium Detector ◽  
Gravimetric Analysis ◽  
Uniform Size ◽  
Transmission Electron ◽  
Physico Chemical ◽  
Radiation Induced ◽  
Surface Decontamination ◽  
Thermal Stability Of

AbstractA nanoparticles chelating solution was synthesized by copolymerization of acrylonitrile (AN) and methacrylic acid (MAA) by radiation induced polymerization technique using 17 kGy irradiation doses. A high copolymer yield was obtained by using 80/20% of AN/MAA and comonomer concentration of 50% (w/w) at a dose rate of 2.58 KGy/h. The resultant cyano group (–CN) of nano-poly(AN/MAA) was converted by chemical modification using hydroxylamine (NH2–OH) to an amidoxime group [–C(=NOH)NH2], which was then confirmed by Fourier transform infrared spectroscopy (FTIR). The physico-chemical properties of poly(AN/MAA) and amidoximated poly(AN/MAA) nanoparticles were studied by FTIR, transmission electron microscopy (TEM), dynamic light scattering (DLS) and thermal gravimetric analysis (TGA). The morphological analysis by TEM and DLS showed a spherical and uniform size of the amidoximated poly(AN/MAA) nanoparticles. TGA results indicated that the thermal stability of poly(AN/MAA) increased by the amidoximation process. The surface decontamination due to uranium was also investigated by the prepared chelating nanoparticles solution. A high purity germanium detector (HPGe) was used as a surface contamination detection tool. The results showed the presence of peaks at different energies, namely, 186.2 keV for Ra-226 (U-238) and 143.76 keV, 163.35 keV and 205.31 for U-235 before the decontamination process. The disappearance of these peaks after decontamination confirmed the applicability and efficiency of the nanoparticles solution in uranium surface decontamination.

scholarly journals Gravimetric analysis of selecteD types of Biofuels

2014 ◽  
Vol 17 (2) ◽  
pp. 53-56 ◽  
Author(s):  
Zuzana Mikulová ◽  
Ivan Vitázek ◽  
Janko Klúčik
Keyword(s):  
Moisture Content ◽  
Heat Generation ◽  
Electricity Generation ◽  
Chemical Properties ◽  
Gravimetric Analysis ◽  
Solid Biofuels ◽  
Physico Chemical

Abstract Biomass provides a great diversity of input materials and universal use, not only for heat generation but also electricity generation in modern incinerators. For the most eficient use of solid biofuels, it is necessary to know their physico-chemical properties. The work focuses on the gravimetric analysis of selected types of biofuels. This paper presents the results of measurements for moisture content, ash and combustibles in selected solid biofuels. Experiments represent a follow-up to measurements performed to date.

scholarly journals Development and Evaluation of Indomethacin Controlled Release Press Coated Tablets

2016 ◽  
Vol 14 (2) ◽  
pp. 187-192
Author(s):  
Muhammad Rashedul Islam ◽  
Md Elias Al Mamun ◽  
Md Mizanur Rahman Moghal ◽  
Md Habibur Rahman
Keyword(s):  
Drug Release ◽  
Xanthan Gum ◽  
Chemical Properties ◽  
Methyl Cellulose ◽  
Compression Pressure ◽  
Physico Chemical ◽  
Compression Coating ◽  
Coating Formulation ◽  
Coating Formulations

In the present work, several batches of indomethacin press coated tablets were prepared with drug and Avicel PH 102 utilizing the press coating technology. The core tablet was compression coated with minimal compression pressure. The compression coating mixture was formulated using various amount of lactose and xanthan gum which was used as the release retarding agent. Three formulations (IX-1, IX-2 and IX-3) were designed to evaluate the release profile as function of xanthan gum load. In vitro drug release testing demonstrated that the drug release was inversely proportional to the amount of xanthan gum in the coating formulations. In addition, formulation IX-2 was modified by incorporating hydroxypropyl methyl cellulose (HPMC) 15 cps into the compression coating formulation to understand their effects on drug release. The formulation was evaluated for its properties and correlated with in vitro and kinetic release studies. Incorporation of HPMC caused the highest fraction of drug to be released in the dissolution fluid. The physico-chemical properties of the excipients can be held responsible for the discrepancy in release rate of indomethacin. From kinetic analysis drug release was found to follow Higuchi mechanism for all the formulations. Overall, the study concluded that excipients present in the coating formulations make a significant impact on drug release.Dhaka Univ. J. Pharm. Sci. 14(2): 187-192, 2015 (December)

Decoration of specific sites on freeze-fractured membranes

1978 ◽  
Vol 36 (2) ◽  
pp. 140-141
Author(s):  
H. Gross ◽  
H. Moor
Keyword(s):  
Pure Water ◽  
Freeze Fracture ◽  
Chemical Properties ◽  
Surface Forces ◽  
Sulfate Pentahydrate ◽  
Copper Sulfate Pentahydrate ◽  
Physico Chemical ◽  
Water Of Hydration ◽  
Small Container ◽  
Binding Forces

Fracturing under ultrahigh vacuum (UHV, p ≤ 10-9 Torr) produces membrane fracture faces devoid of contamination. Such clean surfaces are a prerequisite foe studies of interactions between condensing molecules is possible and surface forces are unequally distributed, the condensate will accumulate at places with high binding forces; crystallites will arise which may be useful a probes for surface sites with specific physico-chemical properties. Specific “decoration” with crystallites can be achieved nby exposing membrane fracture faces to water vopour. A device was developed which enables the production of pure water vapour and the controlled variation of its partial pressure in an UHV freeze-fracture apparatus (Fig.1a). Under vaccum (≤ 10-3 Torr), small container filled with copper-sulfate-pentahydrate is heated with a heating coil, with the temperature controlled by means of a thermocouple. The water of hydration thereby released enters a storage vessel.

Physico-Chemical Properties of Recombinant Desulphatohirudin

1990 ◽  
Vol 63 (03) ◽  
pp. 499-504 ◽  
Author(s):  
A Electricwala ◽  
L Irons ◽  
R Wait ◽  
R J G Carr ◽  
R J Ling ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gel Filtration ◽  
Chemical Properties ◽  
Alpha Helix ◽  
Apparent Molecular Weight ◽  
Correlation Spectroscopy ◽  
Nmr Studies ◽  
Recombinant Hirudin ◽  
Physico Chemical ◽  
Recombinant Molecule

SummaryPhysico-chemical properties of recombinant desulphatohirudin expressed in yeast (CIBA GEIGY code No. CGP 39393) were reinvestigated. As previously reported for natural hirudin, the recombinant molecule exhibited abnormal behaviour by gel filtration with an apparent molecular weight greater than that based on the primary structure. However, molecular weight estimation by SDS gel electrophoresis, FAB-mass spectrometry and Photon Correlation Spectroscopy were in agreement with the theoretical molecular weight, with little suggestion of dimer or aggregate formation. Circular dichroism studies of the recombinant molecule show similar spectra at different pH values but are markedly different from that reported by Konno et al. (13) for a natural hirudin-variant. Our CD studies indicate the presence of about 60% beta sheet and the absence of alpha helix in the secondary structure of recombinant hirudin, in agreement with the conformation determined by NMR studies (17)

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