• Preventive Nutrition and Food Science
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• 제21권1호
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• pp.73-77
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• 2016

Flow and dynamic rheological properties of thickened waters prepared with commercial food thickeners were investigated at different pH levels (3, 4, 5, 6, and 7). The commercial xanthan gum (XG)-based thickener (thickener A) and starch-based thickener (thickener B), which have been commonly used in a domestic hospital and nursing home for patients with swallowing difficulty (dysphagia) in Korea, were selected in this study. Thickened samples with both thickeners at different pH levels showed high shear-thinning flow behaviors (n=0.08~0.22). Thickened samples at pH 3 showed higher n values and lower consistency index (K) values when compared to those at other pH levels. The K values of thickener A increased with an increase in pH level, while the n values decreased, showing that the flow properties greatly depended on pH. There were no noticeable changes in the K values of thickener B between pH 4 and 7. At pH 3, the thickened water with thickener A showed a higher storage modulus (G') value, while that with thickener B showed a lower G'. These rheological parameters exhibited differences in rheological behaviors between XG-based and starch-based thickeners, indicating that the rheological properties of thickened waters appear to be greatly influenced by the acidic condition and the type of food thickener. Appropriately selecting a commercial food thickener seems to be greatly important for the preparation of thickened acidic fluids with desirable rheological properties for safe swallowing.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제28회 추계학술대회
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• pp.306-312
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• 1998

This paper describes syntheses of thickener for di-urea grease using constant velocity joint. The thickeners of di-urea grease were synthesized by reaction of diisocyanate with various alkylamines, hexylamine, octylamine, stearylamine and cyclohexylamine at high temperatxire. The synthesized thickener were analyzed by FT-IR spectroscopy and two kinds of Mass spectroscopy (EI & FAB). Dropping point and Consistency of synthesized di-urea grease were determined.

• Preventive Nutrition and Food Science
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• 제19권3호
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• pp.242-245
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• 2014

The flow behaviors of three thickened fruit juices (orange, apple, and grape juice) prepared with a commercial instant xanthan gum (XG)-based thickener that is marketed in Korea were investigated at different thickener concentrations (1.0%, 1.5%, 2.0%, 2.5%, 3.0%, and 3.5%) and setting times (5 and 30 min) using a rheometer and a line-spread measurement method. The flow distance values measured by the line-spread test (LST) were compared with the apparent viscosity (${\eta}_{a,50}$) values measured with a sophisticated computer-controlled rheometer. The ${\eta}_{a,50}$ values of the juices increased as thickener concentration increased, whereas their flow distances decreased. The ${\eta}_{a,50}$ values at the 30-min setting time were much higher than those at the 5-min setting time, indicating that the setting time before serving or consuming thickened juices can affect viscosity values. Plots comparing ${\eta}_{a,50}$ values to LST flow distances revealed strong exponential relationships between the two measures ($R^2$=0.989 and $R^2$=0.987 for the 5- and 30-min setting times, respectively). These results indicate that the LST can be a suitable instrument for evaluating the viscosity of thickened fruit juices prepared with different XG-based thickener concentrations and setting times for the dysphagia diet.

• Preventive Nutrition and Food Science
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• 제20권2호
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• pp.137-142
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• 2015

Rheological properties of thickened fluids used for consumption by people with dysphagia (swallowing difficulty) are very sensitive to several factors, such as thickener type, temperature, pH, sugar, protein, and NaCl. In this study, steady and dynamic rheological properties of thickened water samples mixed with five commercial xanthan gum-based food thickeners (A~E) were studied in the presence of NaCl at different concentrations (0.3%, 0.6%, 0.9%, and 1.2%). The magnitudes of apparent viscosity (${\eta}_{a,50}$), consistency index (K), yield stress (${\sigma}_{oc}$), and dynamic moduli (G' and G") showed significant differences in rheological behaviors between thickened samples with various NaCl concentrations. Dynamic moduli values of all thickened samples, except for samples with thickener C, were much higher than those of the control (0% NaCl). All rheological parameter values (K, G', and G") in a thickener A were much higher than those in other thickeners. These results suggest that rheological properties of thickened samples containing NaCl are strongly affected by xanthan gum-NaCl interaction and depended on the type of thickener.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2009년도 춘계 학술논문 발표대회 학계
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• pp.101-106
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• 2009

We study on the segregation reduction effect of Self-Leveling Color Mortar by using variable composition set of plasticizer and thickener, Naphthalene, melamine and polycarbonate-based dispersants were employed as plasticizers for examining on fluidity of mortar mixtures. For enhancement of mortar stability without loss of it's fluidity, two types of thickener were used such as polysaccharide(PS) and hydroxyethylcellulose(HEC). As a result, the most effective mortar was composed by feeding 0.519% of polycarbonate-based dispersant with 0.002587% of PS and 0.155844% of HEC on amount of basic mortar.

• 대한화학회지
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• 제20권3호
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• pp.173-184
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• 1976

鋼製毛細管粘度計를 제작하여 윤활유의 流動性質을 연구하였다. 使用한 윤활유는 bentone 윤활유(thickener의 무게 농도 2.0, 4.0, 6.0, 8.0 및 $10.0{\%}$)와 Lime-soap윤활유(thickener의 무게농도 2.4, 7.0, 9.3, 12.1 및 15.2%)이었다. Lime-soap윤활유의 流動性質에 對하여 resident-time(毛細管內에 윤활유가 殘留하는 時間) 效果를 硏究하기 위하여 半徑(R)과 길이(L)를 달리하는 各種毛細管을 使用하였다. 그러나 bentone 윤활유의 流動性質의 仔細한 硏究를 위하여서는 單一種의 毛細管을 使用하였다. 實驗結果(流出量對 shear 速度)에 對하여 Ree-Eyring 式에 나타나는 $X_1{\beta}_1/{\alpha}_1$(Newton 單位에 對한 量), $X_2/{\alpha}_2$ 및 ${\beta}_2$(非 Newton 單位에 對한 量) 等의 係數가 thickener 농도와 溫度에 對하여 어떻게 變化하는가를 보았다. 이 硏究의 分析結果에 依하면 ${\Delta}H_1^{\neq}$와 ${\Delta}H_2^{\neq}$(각각 流動單位 type1과 type2의 流動活性化엔탈피)가 溶媒(base oil)의 流動活性化엔탈피(${\Delta}H_b^{\neq}$)에 近似的으로 一致한다. 이 事實로부터 thickener의 流動單位 (type 1, type 2 공히)는 溶媒分子의 移動으로 因하여 장만된 小孔에 뛰어드러감으로써 全體系의 流動이 이루어짐을 알 수 있다. Bentone 윤활유에 대하여 ${\beta}_2$는 어느 주어진 溫度에 있어서 thickener 농도에 無關함을 알아냈으니 이것은 旣往文獻에 發表된 事實과 一致한다. 殘留時間效果를 lime-soap 윤활유에 對하여 보려고 詩圖하였으나 그 結果는 分明하지 않았다. 그 理由는 lime-soap 윤활유 自身의 性質에도 依存하지만 著者들의 使用한 毛細管의 L/R 値(殘留時間에 比例하는 常數)가 너무 적었음에 原因이 있다고 생각된다.

• Tribology and Lubricants
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• 제28권1호
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• pp.33-37
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• 2012

Automotive wheel bearing grease helps to reduce stresses and prevent wear of wheel bearings. But it is easily contaminated by water and other contaminants. Previously, our research group reported the change of grease physical properties such as dropping point, work penetration and oxidation work stability, water washout characteristics, leakage tendency, oil separation, evaporation loss and rust protection by water contamination. In this paper, we analyzed the physical characteristics of grease such as lubricity, viscosity and total acid number to investigate the mechanism of thickener decomposition. In water contaminated grease, the total acid number and wear scar were increased, the viscosity was decreased due to the decomposition of lithium complex thickener.

• 공업화학
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• 제8권4호
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• pp.673-678
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• 1997

본 연구에서는 associative macromonomer로서 비이온성 vinyl surfactant ester(alkyloxy $poly(ethyleneoxy)_n$ ethyl acrylate)[VSE]를 사용한 유화중합을 통하여 회합형 아크릴 증점제를 합성하고, 유성학적 물성을 고찰하였다. VSE의 소수성 말단기의 탄소수, ethoxylation 정도에 따라 회합형 증점제의 증점제의 증점효과가 크게 영향을 받았다. VSE의 종류를 고정하고, 공단량체 조성을 달리하여 제조한 아크릴 회합형 증점제의 수용액 점도 병화를 고찰한 결과, VSE의 양이 늘어날수록 증점효과가 증가하였다. 이것은 VSE의 소수성 말단기의 상호작용에 의한 회합 증점 메카니즘에 의해 증점효과가 향상되었기 때문이다. 또한 사슬전이제에 의한 분자량이 감소할수록 hydrodynamic volume이 작아져 증점효과가 감소하였다.

• 한국식품과학회지
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• 제49권3호
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• pp.229-234
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• 2017

노화로 인해 삼키는 데 어려움이 있는 노인들을 위한 천연 증점소재 개발을 위해 식이섬유 및 기타 유용한 성분이 함유된 것으로 알려진 마, 연근, 돼지감자 가루를 선택, 시판증점제의 0.5, 1, 2포에 해당하는 점도값을 갖도록 시판 국에 첨가하여 첨가량을 결정하고 점도 및 물리적, 관능적 특성을 비교하였다. 세 천연소재의 호화특성 분석결과, 마가루는 쌀전분과 유사한 최고점도를, 연근가루는 쌀가루보다 큰 최고점도를 보여 증점제로서의 가능성을 보였다. 돼지감자가루는 전혀 호화특성을 보이지 않아 그 자체로는 증점소재로서 바람직하지 않으나, 노인들에게 필요한 식이섬유를 많이 함유하고 있어 잔탄검을 첨가하여 증점제로서의 가능성을 확인하였다. 세 소재를 이용하여 시판증점제의 0.5포 및 1포에 해당하는 점도값을 갖는 첨가량은 결정할 수 있었지만, 천연소재 첨가만으로는 시판증점제 2포에 해당하는 첨가량을 결정하기는 어려웠다. 노인을 대상으로 국에 증점소재를 첨가하여 관능검사를 실시한 결과 마가루 첨가군이 가장 높은 선호도를 얻어 시판증점제를 대체할 천연소재로서의 가능성을 보였다.

• 한국의류산업학회지
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• 제15권5호
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• pp.825-833
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• 2013

In this study, the dyeing properties of Phellodendron amurense on cotton and silk fabrics were evaluated to establish a scientific database of dyeing methods using natural dyes with the ultimate aim of facilitating the practical use of these dyes. The optimal thickener and dyeing concentrations depending on the thickener type were identified when dyeing with P. amurense, and the fabric color, color fastness, and antibiosis were examined for various thickeners, fabrics, and mordants. The results were as follows.: The optimal concentrations of thickeners when dyeing on cotton and silk fabrics were CMC 3% (w/w), Mayprogum 7% (w/w), and Indalka 9% (w/w). The optimal concentration of P. amurense was 25% (w/w), irrespective of the type of thickener. To maintain the hue unique to P. amurense, thickening with Mayprogum or Indalka and mordanting with Al was effective for cotton, while thickening with Mayprogum or Indalka and mordanting with Al or thickening with CMC and mordanting with gallnut was effective for silk. The dry-cleaning fastness and abrasion resistance of cotton fabrics dyed with P. amurense were excellent at the 4-5 level. Gallnut was effective for washing fastness and perspiration fastness against color degradation, and FFC was effective for light fastness. The washing fastness, dry-cleaning fastness, abrasion resistance, and perspiration fastness of silk fabrics dyed with P. amurense were excellent at level 4, except for washing and perspiration fastness, and FFC was effective for the improvement of light fastness. Dyeing cotton and silk fabrics with P. amurense thus yielded antibiosis and excellent washing fastness.