• 제목/요약/키워드: Succinate

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Structural Changes of Biodegradable Poly(tetramethylene succinate) on Hydrolysis

  • Shin, Jick-Soo;Yoo, Eui-Sang;Im, Seung-Soon;Song, Hyun-Hoon
    • Macromolecular Research
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    • v.9 no.4
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    • pp.210-219
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    • 2001

  • Quenched and slow cooled as well as isothermally crystallized poly(tetramethylene succinate)(PTMS) films at two different temperatures were prepared. In the process of hydrolysis of the four specimens, structural changes such as the crystallinity, crystal size distribution, lattice parameter, lamellar thickness, long period and surface morphology were investigated by using wide and small angle X-ray scattering (WAXS and SAXS), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The hydrolytic degradation of quenched film was faster than that of slow cooled and isothermally crystallized films. The film crystallized at 100$\^{C}$ exhibited extensive micro voids and thus showed faster degradation than that crystallized at 75$\^{C}$, demonstrating surface morphology is another important factor to govern degradation rate. The crystallinity of the specimen increased by 5-10% and long period decreased after hydrolysis for 20 days. At the initial stage of degradation, the lamellar thickness of quenched film rather increased, while that of slow cooled and isothermally crystallized films decreased. The hydrolytic degradation preferentially occurred in the amorphous region. The hydrolytic degradation in crystal lamellae are mainly at the crystal surfaces.

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Effect of Various Biodegradable Chelating Agents on Growth of Plants under Lead stress (생분해되는 다양한 킬레이트들이 납에 노출된 식물의 성장에 미치는 영향)

  • Lee, Sang-Man
    • Korean Journal of Environmental Agriculture
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    • v.29 no.1
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    • pp.61-65
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    • 2010

  • Phytoextraction is a method of phytoremediation using plants to remediate metal-contaminated soils. Recently, various chelating agents were used in this method to increase the bioavailability of metals in soils. Even though phytoextraction is an economic and environment-friendly method, this cannot be applied in highly metal-contaminated areas because plants will not normally grow in such conditions. This research focuses on identifying chelating agents which are biodegradable and applicable to highly metal-contaminated areas. Lead (Pb) as a target metal and cysteine (Cys), histidine (His), citrate, malate, oxalate, succinate, and ethylenediamine (EDA) as biodegradable chelating agents were selected. Ethylenediamine tetraacetic acid (EDTA) was used as a comparative standard. Plants were grown on agar media containing various chelating agents with Pb to analyze the effect on root growth. Cys strongly increased the inhibitory effect of Pb on root growth of plants, while, His did not affect on it significantly. The inhibitory effect of oxalate is weak, and malate, citrate, and succinate did not show significant effects. Both EDTA and EDA diminished the inhibitory effect of Pb on root growth. The effect of EDA is correlated with decreased Pb uptake into the plants. In conclusion, as biodegradable chelating agents, EDA is a good candidate for highly Pb-contaminated area.

  • https://doi.org/10.5338/KJEA.2010.29.1.061 인용 PDF KSCI

Development of the submerged heat treatment machine for PBSAT(polybutylene succinate adipate-co-terephthalate) monofilament nets and its efficiency (수중 침지식 생분해성 PBSAT 그물 열처리기 개발과 성능 분석)

  • Park, Seongwook;Kim, Seonghun;Lim, Jihyun;Choi, Haesun
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.51 no.1
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    • pp.94-101
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    • 2015

  • The heat treatment machine based on immersion was developed to reduce temperature difference during netting process and appraised it performance compared current heat treatment machine using high pressure. It was also reviewed the optimum heat treatment procedures for PBSAT monofilament net in accordance with the immersion time and temperature. The procedure was based on physical measurement such as breaking load, elongation and angle of the mesh for PBSAT monofilament. The water temperature gap of the treatment machine based on immersion was less than $1^{\circ}C$. and the energy consumption was also increased in high temperature condition. It was identified that the optimum temperature was $75^{\circ}C$ and its optimum processing time was between 15 minutes and 20 minutes to get qualified physical properties.

  • https://doi.org/10.3796/KSFT.2015.51.1.094 인용 PDF KSCI

Study on the Fermentation Conditions Influencing the Production of Vitamin $B_{12}$ by Propionibacterium shermanii (Propionibacterium shermanii에 의한 Vitamin $B_{12}$생성에 영향을 미치는 발효조건에 관한 연구)

  • 김지영;김공환구양모
    • KSBB Journal
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    • v.7 no.2
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    • pp.126-131
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    • 1992

  • The effects of fermentation conditions and medium compositions on the production of vitamin $B_{12}$ by Propionibacterium shermanii IFO 1239 were studied. Changes from an anaerobic to aerobic condition and a complex to synthetic medium after 48hr resulted in a 100% increase in vitamin $B_{12}$ production compared to an anaerobic culture alone. Glucose, fructose and lactose were found to be equally good as a carbon source for vitamin $B_{12}$ production. Addition of succinate and malate to the synthetic medium with glucose as a carbon source led to an increase in vitamin $B_{12}$ production by 33.6% and 17.2% respectively.

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