• Title/Summary/Keyword: alkali solubility

Search Result 98, Processing Time 0.021 seconds

Determination of the Solubility of Water-Soluble or Alkali-Soluble Pressure Sensitive Adhesives (수용성 및 알칼리 가용성 점착제의 수용성 및 알칼리 가용성 측정)

  • Choi, Jeong Hye;Lee, Myung Cheon
    • Journal of Adhesion and Interface
    • /
    • v.14 no.2
    • /
    • pp.88-94
    • /
    • 2013
  • Because of recent requirement for environmentally-friendly adhesive, water and/or alkali soluble pressure sensitive adhesives are being developed and produced. Our research laboratory newly developed the test method for measuring the water and alkali solubility of the adhesives. Also, we made the test method published both in KS and ISO. In this research, the test of measuring the water and/or alkali solubility of the test adhesive samples as a function of time at various temperatures was carried out using the proposed test method. The results showed this proposed test method made stable output data for the change of solubility as a function of time in the proper range of temperature.

Modification of Wool Treated with Alkali and Alkali/CTAB (I) -Changes of chemical properties- (알칼리와 CTAB 처리에 의한 양모섬유의 개질(I) -화학적 성질의 변화-)

  • 김영리;유효선
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.20 no.5
    • /
    • pp.728-737
    • /
    • 1996
  • The purpose of this study is to investigate the change of the chemical properties of wool treated with six kinds of alkali (NaOH, Naac03, NH40H, NH2CH3CH30H, TMAH and BTMAH) with or without CTAB. Content of bound fatty acid liberated from wool surface, elemental composition and allw6rden time were measured to compare the surface modification of untreated and alkali treated wool. Also, the chemical degradation of the fiber was investigated by measuring cystine contents and urea-hydrogensulfite solubility. The result were as follows: 1. By the alkali treatment of wool, the covalently bound fatty acid of the epicuticle was removed and the allworden time was shortened, and in the case of wool treated with TMAH, BTMAH, the allw6rden sacs were formed unevenly and rarely. Also, cystine contents and urea-hydrogensulfite solubility were decreased by alkali treatment on wool. 2. The modification of epicuticle and the chemical degradation of wool were occurred due to alkaline hydrolysis in the order of TMAH, BTMAH > NaOH, Na3c03> NH2CH3CHaOH, NH40H. 3. As a treating time increased, the modification of epicuticle and chemical degradation of wool were accelerated. By the addition of CTAB to the alkali solution, the modification of epicuticle was increase, and the cystine contents and urea-hydrogensulfite solubility were reduced than that of wool teated with alkli without CTAB due to reduction of negative charge on the wool surface by the adhesion of CTAB.

  • PDF

Hydrolysis of Silk Fibroin on Alkali Conditions (견 피브로인의 알칼리 가수분해)

  • 김남정;배도규
    • Journal of Sericultural and Entomological Science
    • /
    • v.39 no.2
    • /
    • pp.197-202
    • /
    • 1997
  • To hydrolyze silk fibroin was treated with NaOH solution on various concentrations and times. And it was examined that the addition effects of NaHSO3 solution on the solubility and colouring of silk fibroin. As obtained results are as follows; The more increasement of concentration and time of NaOH treatment, the more increasement of solubility but solubility was slight above 3% concentration of NaOH. Fibroin yield was decreased above 3% concentration. This was due to formation of peptide or amino acids below molecular weight 3,000. Most of molecular weight distribution came out to be under 3,000 in 2% concentration and 4hrs of NaOH treatment. The more increasement of adding concentration and 4hrs of NaOH treatment. The more increasement of adding concentration of NaHSO3, the more reduction of solubility but white index of powder increased. In the results of FT-IR spectras of silk fibroin powder obtained by various concentrations of NaHSO3 treatment, the absorbent peak at 3,400 cm-1 which was considered as -CH=N- (azomethine) was disappeared by the more addition of NaHSO3. It showed that absorbent peak of $\beta$-fibroin moved into low temperature region and transferred to $\alpha$- and random coil structure through the DSC experiment. In the results of amino acid analysis, alkali hydrolysis reduced the oxy amino contents acid like serine and tyrosine, but increased the glycine content by the more addition of NaHSO3.

  • PDF

A Development of Fire Protective Coating Based on Soluble Alkali Silicate (알칼리 규산염 내화 피복제의 개발)

  • 이내우;김종래;김정훈
    • Journal of the Korean Society of Safety
    • /
    • v.8 no.2
    • /
    • pp.30-38
    • /
    • 1993
  • To increase fire proofing characteristics of protective coating based on soluble alkali silicate, silicate coatings were studied on thermal properties, IR spectroscopy, solubility and intumescence. Intumescence and solubility of the samples were dependent on the strength of cationic cross-links between polysilicate particles. The degree of intumescence and solubility decrease K-silicate > Na-silicate > Li-silicate in the order. Especially Si$_2$O$_{5}$ $^{-2}$ crystalline regions were found to exist in Potassium silicate sample. Mixture of two kinds of silicate, for example, Lithium silicate when added to sodium silicate or potassium silicate was find to significantly reduce efflorescence and increase water resistance. This appears to be a result of stronger crosslinking between polysilicate particles by the small lithium cation.

  • PDF

Mechanical and Dyeing Properties of Wool Fabric Treated with Papain (파파인 처리한 양모직물의 물성 및 염색성)

  • Sung, Jong-Mi;Kim, In-Young;Song, Wha-Soon
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.34 no.4
    • /
    • pp.697-702
    • /
    • 2010
  • This study researches the mechanical and dyeing properties of wool fabric treated with papain. In this study, shrinkage, water contact angle, alkali solubility, and the dyeability of wool fabric treated with papain at the optimal activity condition were measured to confirm the effect of papain treatment. The shrinkage and water contact angle of wool fabric treated with papain decreased more than the untreated wool; however, the alkali solubility and the dyeability increased. L-cysteine was more active than EDTA as an activator of papain.

Acylation of Wool Keratin with Dibasic Acid Anhydrides(II) ―on properties of acylated wool― (2염기산 무수물에 의한 양모섬유의 아실화(II) -아실화된 양모섬유의 성질을 중심으로-)

  • Shin, Eun Joo;Park, Chan Hun;Choi, Suk Chul
    • Textile Coloration and Finishing
    • /
    • v.8 no.2
    • /
    • pp.64-70
    • /
    • 1996
  • Wool yarns were treated in dimethylformamide solutions containing various concntrations of three dibasic acid anhydrides: succinic, itaconic, and phthalic arthydrides in various conditions. The structurl aspects of these dibasic acid anhydries are different: succinic, itaconic, and phthalic acid arthydrides have saturated aliphatic ethylene, unsaturated aliphatic vinyl and aromatic phenyl one groups, respectively. The properties of acylated wool keratin are as follows: Decreasing amino group and increasing carboxyl group by acylation lowered the hydrophilic property, and then moisture regain, and decreased acid dye uptake and enhanced cationic dye uptake of wool keratin. In the case of phthalic acid anhydries, in spite of lowest acyl content, the minimum of moisture regain was resulted from the bulk benzen ring, occuping much more voids on wool keratin molecules than other reagents. Acid solubility was increased by the decrease of amino group and hydrogen bonding by acylation. Alkali solubility was also increased formation of new amide group on the side chain of keratin, which can be degraded easily by alkali. In the case of phthalic acid anhydride, the relative high solubility was resulted from the much higher molecular weight of dissolved fractions. The surface of wool keratin was not damaged by treatment with any acylating agent.

  • PDF

Physiochemical Characteristics of Corn Starch during the Alkali Gelatinization (알칼리 호화에 따른 옥수수전분의 특성)

  • Cho, Seok-Cheol;Shin, Hae-Hun
    • Korean Journal of Food Science and Technology
    • /
    • v.39 no.6
    • /
    • pp.637-643
    • /
    • 2007
  • In this report, we discussed the physiochemical characteristics of corn starch during the alkali gelatinization process. Here, solubility and the amounts of eluted polysaccharides and amyloses increased in proportion to the amount of alkali added. The X-ray diffraction patterns and DSC thermogram showed that in the early stage of alkali gelatinization, crystallinity of the starch granules was disrupted as compared with heat gelatinization. This resulted in the eluted amylose content, while granule sizes were hardly changed in the alkali treated corn starch. The endotherm peak in the DSC thermogram shifted toward a higher temperature region as the degree of gelatinization increased, suggesting that the retained starch granules were more compactly crystallized during alkali gelatinization than during the heat process. Thus, we concluded that during the alkali gelatinization of corn starch, the disruption of weak particles would occur first, before swelling of the granules.

Interaction of Beta-cyclodextrin with Some Pharmaceuticals (Beta-cyclodextrin과 의약품(醫藥品)과의 상호작용(相互作用))

  • Kim, Shin-Keun
    • Journal of Pharmaceutical Investigation
    • /
    • v.4 no.1_2
    • /
    • pp.13-18
    • /
    • 1974
  • Data are present for the interaction of beta-cyclodextrin with 7 pharmaceuticals in aqueous solution. By means of the solubility method of analysis, definite interaction were found to occur with all the compounds tested. The amount of these pharmaceuticals in equilibrium with their respective solid phase increased progressively with beta-cyclodextrin. A concentration of 1.5 g of beta-cyclodextrin per 100 ml of water increased the solubility of most compounds tested (except one) by 15-120%. Hydrolysis in alkali solution of chrolothiazide was retarded in the presence of beta-cyclodextrin.

  • PDF

A Study on Wool Fabric Treated with Anionic Surfactant and Alkali (음이온계 계면활성제 존재하에서 양모직물의 알칼리 처리에 관한 연구)

  • Lee Jung Boon;Ryu Hyo Seon
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.11 no.2 s.24
    • /
    • pp.101-112
    • /
    • 1987
  • The purpose of this study is to investigate the influence of addition of sodium dodecyl sulfate(SDS) when wool is treated with sodium hydroxide(NaOH). Physical and chemical changes were examined on wool treated with various cone. of NaOH and SDS simultaneously. The result are as follows. 1. The higher the temperature and the longer the time of NaOH treatment are, the more alkali damage wool get : increase in weight loss and decrease in urea-bisalphite solubility and in tensile strength. But the treatment time reacts less effective than the temperature. 2. When wool is treated with NaOH, at NaOH cone. under $10^{-3}M$., the addition of SDS alleviates the alkali reaction on wool: increase in cystine contents and in urea-bisulpite solubility, and decrease in degree of swelling. On the other hand, at NaOH cone. over $10^{-2}M$., the addition of SDS promotes the alkali reaction on the wool. 3. When wool is treated with NaOH, the addition of SDS shows no changes on the tensile strength. On the other hand, at NaOH cone. under $10^{-2}M$., the addition of SDS shows no changes on the softness of wool, but at the $10^{-1}M$. NaOH cone. addition of SDS increases the soft-ness of wool. The area shrinkage of wool treated with NaOH and SDS shows less changes than with NaOH only.

  • PDF