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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.

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.

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.

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.

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.

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.

The purpose of this paper is to study the performance variability of the commercially available engine oils based on physico‐chemical and tribological performance parameters.

The study does this by evaluation of physico‐chemical parameters of flash point, pour point, TAN, sulphated ash, viscosities @ 40 and 100°C and VI; and the tribological performance in terms of friction, wear, weld load and the load bearing capacity of the lubricant film under the point and line contact geometries.

Correlation between some of the physico‐chemical properties and tribological performance parameters could be made and the variation in performance of the lubricants assessed.

The findings will be important to the engine oil producers and the users.

To study the changes occurring in lac‐polyvinyl butyral (PVB) resin blends at molecular levels on baking the blends at 200°C for different intervals of time. It was also to ascertain the changes in key physico‐chemical parameters of these blends, before and after applying thermal stress on these blends.

Films of lac‐PVB blends, applied on tin panels were baked at 200°C for different time intervals. The FTIR spectra of the blends were recorded using specular reflectance spectroscopic techniques. The results obtained were compared and reported. The blends were also tested for different physico‐chemical parameters such as scratch hardness, flexibility, adhesion, acid resistance, etc.

On baking the blends of lac‐PVB resin at 200°C for different time intervals; fragmentation reaction, that is breakdown of products into small molecules, takes place in lac‐PVB blends. Side products such as acetic acid emerge on baking the blends. Probably hydrolysis of oxirane ring also takes place leading to the release of free alcoholic groups. The lac‐PVB blends do not show any improvement in scratch hardness and are also not resistant to the action of acids. The blends made by lac‐PVB resin baked at 200°C do not seem to be compatible as no improvement in any of the physico‐chemical parameters was seen.

Mixtures of solvents were tried for dissolving the PVB resin. In most of the solvent mixtures, PVB resin forms big lumps and is not soluble so there is a need for universal solvent for dissolving the PVB resin. The spectral studies on lac‐PVB blends were conducted qualitatively, although desirable, quantitative studies could not be carried out, due to the inherent difficulties in handling the resins.

The parent resins in lac‐PVB blends (baked at 200°C) do not seem to be compatible with one another as there was no improvement in any of the physico‐chemical parameters of the lac‐PVB blends. For making lac‐PVB blends, low range of baking temperature may be tried.

In literature, there is not much evidence of making lac‐PVB blends. This paper is the first one in attempting to obtain and correlate FTIR spectra of the lac‐PVB blends with physico‐chemical changes of the blends. This paper also highlights the convenience of the method and the scope of sophisticated data analysis such as derivative spectrometry.

The purpose of this paper is to develop poundmix for reconstitution as pounded yam, from yam, cocoyam, breadfruit and plantain and to evaluate their physico‐chemical and sensory properties.

Instant flour of the components was prepared separately and 30‐50 per cent composite blends of poundmix were formulated. The physico‐chemical, and sensory properties of the poundmix were determined and the results were subjected to appropriate statistical analysis.

The swelling capacities of the poundmix are 3.14±0.03, 3.13±0.04, 3.81±0.01 per cent for 30, 40 and 50 per cent composite levels, respectively, as against 2.27±0.04 per cent for yam flour. Whole yam flour compared well with the composites in terms of peak temperatures with the 40 per cent composite flour having the highest pasting temperature 93°C and 50 per cent composite with the lowest (72°C). However, the higher the composite level the lower the peak viscosity as 390, 260, 210, and 190 BU were recorded for 0, 30, 40 and 50 per cent composites, respectively (F=3.18, p<0.05).

These findings showed that supplementing poundo yam at 40 per cent composite level should be practiced as it gives the best physico‐chemical properties and sensory score.

The purpose of this paper is to evaluate the physico‐chemical properties of African star apple (Chrysophylum albidum) components. African star apples are among the under‐utilized fruits in Nigeria therefore, the four succulent components (peel, pulp, juice and pericarp) of the fruit were analyzed and compared with other known fruits.

African star apples were purchased and divided into two portions. The first portion was washed and the juice was expressed manually into a bottle and covered, while in the second portion, the peel, pulp and the pericarp (mucilage on the seeds) were separated. The physico‐chemical analyses (moisture, total solid, pH, titratable acidity, total sugar, carotenoids, ascorbic acid and total soluble solids) were carried out on the four components.

Moisture content ranged from 53.5 per cent in peel to 86.3 per cent in juice, while the peel had higher total solid and the least was in the juice. The pH of peel was lower than that of other components. The peel had lower titratable acidity (1.2 per cent) and sugar (0.9 Brix) while the juice had higher value (5.4 Brix) in sugar and 15.0 mg/100 g carotenoid. The juice was rich in ascorbic acid (28.5 mg/100 g) followed by the pulp (25.0 mg/100 g). The pulp had higher total soluble solids (24.8 per cent) and the least was in the pericarp (9.8 per cent).

The physico‐chemical properties of the African star apple fruit gave an indication of the usefulness of this fruit in brewing industry especially for wine making and jelly or jam manufacture. Processing of this fruit will curb wastage during its season and make it available in different form.

The purpose of this paper is to characterize oils extracted from Bertholletia excelsa, Lecythis pisonis, Dipteryx lacunifera, Carya illinoensis and Juglans regia, regarding their characterization and fatty acid profile.

The oils were extracted from oilseeds by cold pressing and physico‐chemical characterization was performed by using standard methods for oils and fats. The oxidative stability and fatty acid profile also were determined.

According to the results, the physico‐chemical properties of oils from nuts and walnuts were comparable to those of good quality conventional oils. The oil seeds are a good source of unsaturated fatty acids, especially oleic and linoleic acids.

Implies the identification of fatty acid profile and physico‐chemical properties of oils extracted from nuts and walnuts, and to prevent certain types of diseases.

The paper identifies a new source of essential fatty acids extracted from oilseeds.

The purpose of the present study was to investigate the effect of camel milk protein hydrolysates (CMPHs) on physico-chemical, sensory, colour profile and textural quality attributes of chevon patties.

Camel milk proteins were hydrolyzed with three different proteolytic enzymes, viz., alcalase (CMPH-A), α-chymotrypsin (CMPH-C) and papain (CMPH-P), and dried to powder form before further utilization. Four treatments were prepared with incorporation of CMPH, viz., CMPH 0 per cent (C), CMPH-A 0.09 per cent (T₁), CMPH-C 0.06 per cent (T₂) and CMPH-P 0.09 per cent (T₃), in the product formulation. The developed goat meat patties were evaluated for physico-chemical (pH; emulsion stability, ES; cooking yield, CY; water activity, a_w), instrumental colour and texture profile and sensory attributes.

The pH, moisture, fat and ES values of goat meat emulsions were comparable amongst treatments as well as with the control; however, treated emulsions had higher ES and moisture content. The pH and moisture per cent of cooked chevon patties varied significantly, whereas other physico-chemical (CY, a_w, per cent protein, per cent fat, per cent ash and per cent dietary fibre) as well as dimensional parameters (per cent gain in height and decrease in diameter) were comparable amongst treatments and the control. Hardness, springiness, stringiness, cohesiveness, gumminess and resilience of chevon patties decreased significantly (p < 0.05) with the incorporation of CMPH than that of the control; however, the values were comparable among all the treated products. Protein hydrolysate in chevon patties resulted in significant increase in redness (a*) values, whereas all other parameters (L*, b* and hue) decreased significantly as compared to that of the control. The colour and appearance, texture, juiciness overall acceptability scores were comparable in all the treated products and were significantly (p < 0.05) higher than the control. The flavour scores of C, T₁ and T₃ were comparable but significantly lower than that of T₂. The overall acceptability scores of T₁ and T₂ were also comparable and significantly higher than C and T₃; however, the highest score was recorded for T₂.

Results concluded that chevon patties with acceptable sensory attributes and improved CY and textural attributes can be successfully developed with the incorporation of CMPH.

The protein hydrolysates of different food proteins could be explored in a same pattern to find out their implication in food matrices.

This paper aims to gain a greater insight into the molecular level changes occurring in lac‐epoxy blends, at elevated temperatures for different intervals of time. It is also to determine the changes in key physico‐chemical parameters of these blends, before and after applying thermal stress on these blends.

Films of lac‐epoxy blends, applied on tin panels, were baked at 200°C for different time intervals. The baked films were examined by specular reflectance spectroscopy, as these were otherwise difficult to examine through conventional IR techniques, using KBr pellet method. The results obtained were compared and reported. The blends were also tested for different physico‐chemical parameters like scratch hardness, flexibility, adhesion, acid resistance, etc.

On baking the blends of lac‐epoxy resin at 200°C for different time intervals, the strained three membered epoxy ring apparently break open, releasing some free hydroxyl groups, which react with carboxylic groups in lac resin to form ester linkages, resulting in condensation. In terms of different physico‐chemical parameters, blends of 70 per cent lac:30 per cent epoxy were found to be better in performance than blends of 50 per cent lac:50 per cent epoxy and blends of 30 per cent lac:70 per cent epoxy resins, baked at 200°C for different time intervals. Adhesion and acid resistance of lac‐epoxy blends were very good compared with the parent resins.

The spectral studies on lac‐epoxy blends were done qualitatively. Although desirable, quantitative studies could not be carried out, due to the inherent difficulties in handling the resins.

Lac‐epoxy blends may find an important role in printing inks, varnishes and finishing industries owing to their very good adhesion, gloss, scratch hardness and resistance to the action of acids.

As of now, there is no record of specular‐reflectance and derivative spectrometric studies on lac‐synthetic resin blends. This paper represents the first attempt to obtain and correlate reflectance data with physico‐chemical changes. It also highlights the convenience of the method and the scope of sophisticated data analysis, including derivative spectrometry and spectral subtraction techniques.

The wool scales present on the fibre surface give rise to certain unwanted effects in textile wet processing, for example, felting and poor wettability. In the past, the removal of scale was done either through physical/chemical degradation of the scales or by deposition of polymer on the scales. In modern treatments, a combination of both methods are usually carried out. Because the deposition of polymer on the fibre surface depends greatly on the surface characteristics of the fibre, therefore, the surface properties of modified fibres are important factors for polymer application. On the other hand, the modified surface may also result in improved wettability of the fibre. The present paper investigated the surface physico-chemical properties of wool fibres subjected to different surface modification treatments.

In this paper, Soxhlet extracted (dichloromethane extracted) wool fibres (21 J..lm diameter) were modified by potassium permanganate / salt treatment, sodium metabisulphite treatment and plasma treatments (oxygen, nitrogen, 25% hydrogen and 750% nitrogen gas mixture). The study of wool fibre surface physico-chemical properties included contact angle measurement with different solvents, critical surface tension, surface free energy and saturated adsorption value. Experimental analysis showed that these properties were imQroved after the surface modification treatments, and the results were calculated quantitatively and discussed.

This paper aims to examine the quality of the surface waters of the bitumen deposit area of Nigeria and also to establish the relationship between the deposit and the waters.

Physico-chemical parameters were measured using standard analytical procedures, while the elemental contents were determined using total reflection X-ray fluorescence spectroscopy. Data acquired were interpreted using statistical techniques – charts, t-test, pollution index (PI) and cross-plot analysis.

A river located close to the bitumen well contained the highest concentrations of metals that are known to be associated with hydrocarbon formation. Comparison of the levels of the analyzed parameters in the waters with their standard permissible limits showed that the levels of Cl−, SO₄2-, total alkalinity and Cr, Mn, Fe, Ni, Cu, Zn and Pb in the river very close to the capped bitumen well and big rivers were high and low in the small streams. This was corroborated by their pollution index values. Results of the cross-plot analysis of the waters-river close to bitumen well/bitumen (R2=0.5); small streams/bitumen (R2=0.8) and big rivers/bitumen (R2=0.2) showed moderate; strong and weak positive correlations respectively, suggesting moderate, strong and weak inter-element correlations respectively between the sets of waters and the Nigerian bitumen deposit, and also establishing relationships between the deposit and the surface waters.

The paper provides insight into the potability of the waters; establishment of the inter-element relationship between the bitumen deposit and the waters. These results can serve as a fingerprint for bitumen exploration elsewhere and for similar mineral deposit settings.