• Title, Summary, Keyword: Rosin

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Rosin Microparticles as Drug Carriers: Influence of Various Solvents on the Formation of Particles and Sustained-release of Indomethacin

  • Lee Chang Moon;Lim Seung;Kim Gwang Yun;Kim Do Man;Kim Dong Woon;Lee Hyun Chul;Lee Ki Young
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.9 no.6
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    • pp.476-481
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    • 2004
  • The aim of this study was to formulate a sustained release system for indomethacin (IND) with rosin gum obtained from a pine tree. Rosin microparticles were prepared by a disper­sion and dialysis method without the addition of surfactant. In order to investigate the influence of solvents on the formation of colloidal microparitcles, various solvents like ethanol, DMF, DMAc, and acetone were used. The rosin microparticles containing IND were characterized by X­ray differactometry (XRD) and differential scanning calorimetry (DSC). The morphologies of rosin microparticles observed by scanning electron microscopy (SEM) were spherical. The solvents used to dissolve rosin significantly affected the drug content and drug release rate of IND. The release behaviors of IND from the rosin microparticles were dependent on the drug content and size of the particles. Rosin micorparticles with a higher drug content and of a larger particle size had a slower drug release rate. Also, the IND release rate from the rosin microparticles could be regulated by the rosin content in the microparticles. From these results, rosin microparticles have the potential of being used as a sustained release system of IND.

Studies on the Temperature Effect to Rosin Size in Paper Making (로진 싸이즈에 미치는 溫度의 影響에 關하여)

  • Dong Bum Chi
    • Journal of the Korean Chemical Society
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    • v.7 no.2
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    • pp.133-139
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    • 1963
  • It is well-known that high temperature hurts the sizing effect of rosin size in paper making, mainly owing to the particle size of rosin-aluminium complex in paper stock. In this experiments, author find, when the temperature of stock rises up. the particle size of rosin-aluminium complex of neutral rosin size increases and the degree of sizing decreases finally. However, the behavior of Bewoid size is quite opposite to former. This result showed that, Bewoid size is suitable in hot summer and neutral rosin size in cold winter for better sizing effect.

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Effects of Rosin Pre-treatment on the Quality of Digital Printing on Textiles (로진 전처리가 DTP(Digital Textile Printing)에서 미디어의 프린팅성에 미치는 영향)

  • Park, Soon-Young;Jeon, Dong-Won;Park, Yoon-Cheol;Lee, Beom-Soo;Cho, Hang-Sung
    • Textile Science and Engineering
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    • v.48 no.3
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    • pp.172-179
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    • 2011
  • Rosin pre-treatment was studied to improve the quality of digital textile printing. Silk and cotton media were tested with reactive and pigment inks. The K/S value of cotton printed with reactive ink was decreased by rosin treatment. The K/S values of cotton and silk printed with pigment inks were increased by rosin treatment, making rosin-treated samples more effective in obtaining dark color during pigment ink printing. MIU, MMD, and SMD values, closely related to surface roughness and printing quality, were lowered by rosin treatment. B and 2HB values increased with increasing concentration of rosin used during treatment. Line printing tests showed decreased line blurriness of rosin-treated silk and a sharper line was printing.

Characterization of the PAC Modified Cationic Rosin Size and its Sizing Effect

  • Yan, Yong-Xiang;Chandranupap, Fu-Shan;Wang, Gao-Sheng
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • pp.387-390
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    • 2006
  • Cationic rosin sizes are prepared by premixing extremely pure ployaluminum chloride (PAC) and dispersed rosin size (DRS). It turned out that zeta potential and particle size of the sizing agents took a big change by Plus90 analyzer's and FTIR analyzer's analysis. It turned out that -C=O and -COOH of the DRS have both chemical reaction with PAC to form the muti-hydroxyl aluminum rosin acid and that the cationic rosin sizes modified by PAC has dissymmetric and symmetric flexible vibration two absorbing peaks of the groups (its absorbing peaks $at1596cm^{-1}\;and\;1425cm^{-1}$). By DRS reacting with PAC, zeta potential of the resin size varied from negative to cationic. $Al_{2}O_{3}/rosin=1:0.3$, zeta potential of premixed admixture is tiptop28.8mv, When joined continuously PAC, zeta potential of cationic rosin sizes descend on the contrary.

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Coagulation of Cationic Rosin Emulsion and its Effect on Ink Receptivity of Coating Layer (양이온성 로진 에멀션의 응결현상이 도공층의 잉크흡수성에 미치는 영향)

  • 박철웅;이학래
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.30 no.3
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    • pp.74-83
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    • 1998
  • The phenomenon of decrease in sizing efficiency when the stock temperature is increased is well recognized as summer sizing, and this is believed to be caused by uneven distribution of sizing agents on paper surface most often incurred by coagulation of sizing agents. When unevenly sized paper is used as coating base stock, nonuniform consolidation of the coating layer may result, which, in turn, causes uneven distribution of binder on coating surface. This causes nonuniform ink absorption to produce print mottle. In this study the effects of simple or polymeric electrolytes, storage temperature and time on the coagulation of cationic dispersed rosin size were investigated using a turbidity measurement method which was verified to correlate well with the particle size of rosin emulsion or its coagulates. Handsheets sized with rosin dispersions coagulated under various conditions were prepared and their sizing degree and coated paper properties including gloss and ink density were examined. The relationship between the sizing nonuniformity of coated papers and its ink absorption property was evaluated. Turbidity of rosin emulsion increased as the storage temperature and time were increased. Addition of simple or polymeric electrolytes caused reduction in $zeta$ -potential of the rosin dispersion and accelerated the coagulation tendency substantially. Reversion of the $zeta$ -potential of rosin dispersion, however, did not occur when coagulation was induced with simple electrolytes. On the other hand, addition of an anionic polyelectrolyte reversed the $zeta$ -potential of the flocculated rosin dispersion. This indicated that electrical double layer compaction and bridging flocculation were coagulation mechanisms for simple and polymeric electrolytes, respectively. Sizing degree decreased as coagulation of rosin was increased. Paper gloss, ink gloss and ink density were increased when sizing degree of base stock was increased most probably due to prevention of base paper swelling and increased binder migration to coating surface. This suggested that uneven printing ink density occurred when uneven sizing development was induced by coagulation of rosin particles.

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Molecular Weight Distribution of Rosin Modified Phenol Resin Used in Media for Printing Varnishes. (인쇄잉크용 로진변성 페놀수지의 분자량 분포에 관한 연구)

  • SungBinKim
    • Journal of the Korean Printing Society
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    • v.7 no.1
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    • pp.65-72
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    • 1989
  • Modified phenolics can have a retarding effect on the gelation of wood oil. Modified phenolic resins can be used in media for paint, varnishes, primers, overprinting varnishes, litho, letterpress and rotogravure inks. Varnishes based on rosin phenolic are faster drying, have better durability, are harder and glosser, and have greater resistance to water than ones based on ester gums. These physical properties is concerned with molecular weight distribution of rosin modified phenol resin. This paper was studied about molecular weight distribution of rosin phenolics which were prepared between $130~250^{\circ}C$. The results were as follows: 1) Average molecular weights inereased with increasing reaction temperature. 2) $M_w/M_n$ were from 3.43 to 46.44 with increasing reaction temperature and so the molecular weight distributions were changed from random distribution to broad distribution. 3) The relation ship between intrinsic viscosity and weight average molecular weight was follows: $[{\;}{\;}]={\;}1{\times}{\;}10^{-6}M_w,{\;}M_w=M_w$ 4) Esterification reaction between the acid group of rosin and polyol was started about $230^{\circ}C$$.

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Deterioration Mechanism of Paper according to Sizing and Beating(I)-Influences of Sizing- (사이징과 고해에 따른 종이의 열화기구(제1보)- 사이징의 영향 -)

  • 김봉용
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.30 no.2
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    • pp.24-29
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    • 1998
  • This study was carried out in order to elucidate the deterioration mechanism of paper according to various sizing chemicals. No additive paper and four kinds of papers containing rosin-alum, alum only, alkylketene dimer(AKD)-cation polymer and cation polymer only were treated by UV light to study changes of water-resistant, optical and mechanical properties from the view points of natural deterioration of paper. Since rosin chemicals have UV absorption at the relatively long wavelength region, rosins are degraded to form hydrophilic groups such as carboxylic acid from their double bonds by UV treatments. These phenomena caused the decreasing of sizing degree and wetting time in case of rosin-sized paper, while the UV treatments brought about the slight increase of wetting time in rosin-free papers such as no additive, alum and kymene only paper owing to the auto-sizing effect. Optical properties were primarily influenced by sizing chemicals. Rosin-sized paper showed lower brightness after UV and near UV treatment because of its UV instability.

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Peel Stength of the Acrylic Copolymer and Pressure Sensitive Adhesives (아크릴계 점착제의 박리강도와 점착부여제)

  • 김현중
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.31 no.1
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    • pp.79-88
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    • 1999
  • The stability and performance (peel strength) of the acrylic copolymer and various modified rosin systems were investigated. The peel strength was measured over a wide range of scaling rates, and the influence of the viscoelasticity of the PSA(pressure sensitive adhesive) was considered. In the case of miscible systems, the peak of peel strength (PSA performance) over wide peel rates was changed and modified systematically with increasing glass transition temperature of the blends. The peak of the peel strength for blended systems shifts toward the lower rate side as glass transition temperature ($T_g$) of the blend increased. The influence of esterification of the rosin on performance and stability against deterioration was greatly modified by blending with rosin of glycerol ester and rosin pentaerythritol ester. The failure mode of the blend varies with the combination with acrylic copolymer and modified rosin, and cohesive failure was found at a lower peel rate while interfacial failure was found at a high peel rate. A few systems where a single Tg could be measured, despite the fact that two phases were observed microscopically, were detected.

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A Study of Effect of Droplet Distribution Functions in Modeling of Pressure-Swirl Atomizer (압력 선회 분사기 분무모델에서 액적분포함수 영향 고찰)

  • Moon, Yoon-Wan;Seol, Woo-Seok;Yoon, Young-Bin
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • pp.117-120
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    • 2007
  • This study investigated the spray modeling of the pressure-swirl atomizer installed in liquid rocket engine and the effect of drop distribution function especially. The $X^2$, originally implemented to KIVA, Rosin-Rammler and modified Rosin-Rammler distribution functions were investigated theoretically and compared to each other. Also, they were applied to pressure-swirl atomizer similar to the injector installed in liquid rocket engine to evaluate the feasibility for LRE injector. Among the distribution functions, original Rosin-Rammler distribution function was the most compatible with predicting the spray characteristics of pressure-swirl atomizer installed in liquid rocket engine.

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Synthesis and Characteristics of Unsaturated Polyester Modified with Rosin Containing 2-Hydroxyethylmethacrylate (2-Hydroxyethylmethacrylate가 도입된 로진 변성 불포화 폴리에스테르의 합성과 그 특성)

  • Kang, D.W.;Yoon, D.K.;Kweon, D.K..
    • Applied Chemistry for Engineering
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    • v.10 no.3
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    • pp.450-455
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    • 1999
  • Unsaturated diol (UD) was prepared from the esterification of maleic anhydride with diethylene glycol (DEG). Unsaturated polyesters modified with rosin (UPMR) or with rosin maleic anhydride adduct (RMA) from 2-hydroxyethylmethacrylate (HEMA) and rosin (UPMRH) were prepared by the reaction of UD with RMA or RMA-HEMA. After crosslinking of UPMR and UPMRH with styrene and methylmethacrylate (MMA), respectively, solvent resistance, tensile strength, and adhesion property of the resins were measured. UPMR crosslinked with styrene or MMA shows an excellent resistance to water and acid. Solvents resistance and tensile strength of UPMR using styrene as crosslinking agent were increased compared with those of UPMR using MMA as crosslinking agent. UPMRH showed better solvents resistance and tensile strength than UPMR. Adhesion strengths of UPMR crosslinked with styrene and MMA were 1.61 and 3.02 MPa, and those of UPMRH were 2.32 and 3.89 MPa, respectively.

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