• 제목/요약/키워드: Molecular Weight Properties

검색결과 1,241건 처리시간 0.028초

두류 전분의 분자구조적 특성 (Molecular Structural Properties of Legume Starches)

  • 권미라;안승요
    • 한국식품과학회지
    • /
    • 제25권3호
    • /
    • pp.264-269
    • /
    • 1993
  • 아밀로오스와 아밀로펙틴의 고유점도와 중합도는 강남콩이 다른 시료에 비해 작았다. 겔 크로마토그래피에 의한 분자량 분포의 연구에서는 전분의 경우 강남콩이 대체로 작은 분자들이 많음을 보여주었다. 아밀로오스의 분자량 분포는 특히 강남콩 아밀로오스가 분자량이 작은 것으로 나타났으며 동부와 녹두는 강남콩이나 팥보다 컸고, 팥은 중간이었다. 아울러 아밀로펙틴의 경우 pullulanase로 분해시켰을 때 잘라지는 가지 부분들이 강남콩은 약간 짧았고 동부나 녹두는 강남콩보다는 길었으며 서로 비슷했다. 또한 동부나 녹두는 긴 사슬(DP 40 부근)에 비해 짧은 사슬(DP 15 부근)의 비율이 더 크게 나타났다.

  • PDF

Aggregation of Fibroin Molecular in Aqueous Solution

  • Son, Hyo-Jin;Hur, Won;Jeong, Jae-Ho;Kim, Ji-Young
    • 한국생물공학회:학술대회논문집
    • /
    • 한국생물공학회 2003년도 생물공학의 동향(XIII)
    • /
    • pp.634-638
    • /
    • 2003
  • For the investigation of the properties of aqueous fibroin solution, the variation of molecular weight by agregation of silk, morphology and difference of molecular weight at pI value was investigated. The distribution of molecular weight investigated using gel filtration chromatography and formation of aggregates were confirmed by using Field emission scanning electron microscope. The precipitation of fibroin solution at its pI value was compared by molecular weight distribution and the formation of fibroin aggregated were investigated. The aggregation kinetics were investigated at various condition.

  • PDF

폴리카복실레이트계 고성능 유동화제의 합성과 시멘트계 내의 유동 및 수화 반응 거동 (Synthesis of High-Performance Polycarboxylate(PC)-Type Superplasticizer, and Its Fluidity and Hydration Behavior in Cement Based-System)

  • 신진용;채은진;홍지숙;서정권;황의환
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
    • /
    • pp.77-80
    • /
    • 2006
  • Graft copolymerized polycarboxylate(PC)-type superplasticizers(PCs) which have carboxylic acid with $\pi$ bond among the molecular structure and polyethyleneglycol methyl ether methacrylate(PMEM) were synthesized by free radical reaction and investigated the chemical structure, polymerization condition, and physical and chemical properties. Also, the effects of PCs in the dispersion, adsorption and hydration of cement were evaluated. As the molecular weight of graft chain decreases, the adsorption amount on cement particles increased. It was advantageous for the flow to reduce molar ratio, the lower the side bone molecular weight, and increase the molar ratio, the larger the side bone molecular weight. The hydration reaction speed was highly delayed at day 1, due to increase in molar ratio and reduction in side bone molecular weight, but it was recovered in the days after.

  • PDF

Nanocomposites Based on Polytetrafluoroethylene and Ultrahigh Molecular Weight Polyethylene: A Brief Review

  • Kirillina, Iu.V.;Nikiforov, L.A.;Okhlopkova, A.A.;Sleptsova, S.A.;Yoon, Cheonho;Cho, Jin-Ho
    • Bulletin of the Korean Chemical Society
    • /
    • 제35권12호
    • /
    • pp.3411-3420
    • /
    • 2014
  • Deficiencies in wear and frost resistance as well as mechanical strength constitute the main causes of equipment failure under the harsh climatic conditions of the Earth's polar regions. To improve the properties of the materials used in this equipment, nanoparticle composites have been prepared from clays such as kaolinite, hectorite, and montmorillonite in combination with polytetrafluoroethylene (PTFE) or ultrahigh molecular weight polyethylene (UHMWPE). A number of techniques have been proposed to disperse silicate particles in PTFE or UHMWPE polymer matrices, and several successful processes have even been widely applied. Polymer nanocomposites that exhibit enhanced mechanical and thermal properties are promising materials for replacing metals and glass in the equipment intended for Arctic use. In this article, we will review PTFE- and UHMWPE-based layered silicate nanocomposites.

전력케이블 절연층용 원재료의 특성비교 (Characteristic Comparison of Raw Materials Used for Power Cable Insulation)

  • 오우정;고정우;김종은;서광석;이건주
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1997년도 추계학술대회 논문집 학회본부
    • /
    • pp.302-304
    • /
    • 1997
  • Chemical structure and electrical properties such as water treeing and space charge accumulation of various raw materials(XLPE) used for power cable insulation were investigated. It was found that chemical structure was changed after crosslinking reaction and every materials have different amounts of DCP and antioxidant. Electrical properties were also changed after extraction using $CHCl_3$ and xylene. Water tree length was smaller with additives such as DCP and antioxidant and bigger with low molecular weight components of polyethylene than that of extracted samples. Heterocharge was changed into homocharge after extraction. This shows that additives and low molecular weight components of polyethylene cause the heterocharge.

  • PDF

로진 변성 페놀 수지의 분자량 변화에 따른 인쇄 잉크의 유변학적 특성에 관한 연구 (The Rheological Properties of Printing Ink according to the Molecular Weight of Rosin Modified Phenol Resin)

  • 이규일;김성빈;김태환
    • 한국인쇄학회지
    • /
    • 제24권1호
    • /
    • pp.1-12
    • /
    • 2006
  • The rheological characteristics of an ink relate to its performance on the press and to the printing quality such as ink stability, transfer characteristics, mottle, squash, misting, dot gain, and so on. For lithographic print, the emulsification of ink is an important factor to determine the product. And also the rheological characteristics of the emulsified ink should be investigated. Thus, in this study, the effects of the changing molecular weight of rosin modified phenolic resin on the water-pickup ratio of neat inks were studied. And then rheological properties of neat inks and emulsified inks with changing molecular weight of rosin modified phenolic resin were analyzed by using rotational rheometer.

  • PDF

감귤과 유자중의 펙틴질의 이화학적 성질 (Physicochemical Properties of Pectic Substances from Citrus Fruits)

  • 이헌주;이혜수
    • 한국식품조리과학회지
    • /
    • 제6권1호
    • /
    • pp.9-12
    • /
    • 1990
  • This study was carried out in order to investigate the physicochemical properties of isolated pectic substances from Citron, Satsuma mandarin, Marumero, and Natsudaidai. Among varieties, Citron had the highest value of isnoluble pectin and Marumero had the hightest ratio of soluble pection. The total pectin contents isolated by 2% Sodium hexameta-phosphate(SHMP) varied in the range of 1.85% ~ 2.63%. Anhydrogalacturonic acid(AUA) contents were 78.64%~89.14% and were lower than commercial pectin. Isolated pectin contained above 7% methoxyl content and above 50% esterification. The apparent molecular weight of commercial pectin and isolated pectin were 72,000 and 42,000~46,000 respectively. Esterification and ester methoxyl content were the lowest and apparent molecular weight was the highest in Satsuma mandarin. Citron's values were a little higher in esterification and ester methoxyl content and lower in apparent molecular weight than the others.

  • PDF

분자량에 따른 키토산 필름의 특성 (Molecular weight of chitosan affect characteristics of chitosan films)

  • 임종환;함경식;박선영
    • 한국포장학회지
    • /
    • 제6권1호
    • /
    • pp.24-30
    • /
    • 2000
  • 분자량이 다른 네 종류의 키토산으로 제조한 필름의 색깔, 수증기투과도, 수분용해도, 인장강도 및 연신율을 측정하여 키토산 필름의 특성에 미치는 키토산의 분자량의 영향에 대해 조사하였다. 일반적으로 키토산 필름의 총색차와 수분용해도는 키토산의 분자량이 증가할수록 감소하였으며, 반면에 인장강도와 연신율은 키토산의 분자량이 증가할수록 증가하는 경향을 나타냈다. 키토산 필름의 수증기투과도는 키토산의 분자량과 뚜렷한 상관관계를 보이지 않았다.

  • PDF