• Title, Summary, Keyword: fiber type composition

Search Result 112, Processing Time 0.054 seconds

Synthesis and Properties of Poly (trifluoropropylmethyl -dimethyl) Siloxane-Polyurea Copolymers (II)-Synthesis and Mechanical Properties of Polysiloxane-Polyurea Copolymers- (폴리(트리플루오로프로필메틸-디메틸)실록산-폴리요소 공중합체의 합성과 성질(II) -폴리실록산-폴리요소 공중합체의 합성과 기계적 성질-)

  • 박성균;고석원
    • Textile Science and Engineering
    • /
    • v.33 no.3
    • /
    • pp.263-272
    • /
    • 1996
  • In order to improve the mechanical properties and to utilize the useful properties of siloxane, -(AB) - type copolymers hove been the subject of study. The copolymers composed of siloxane(A) with functionalized end group as a soft segment and organic polymer(B) as a hard segment. In this study, -(AB) - type polysiloxane-polyurea copolymers were synthesized by reacting the g, m aminopropyl-terminated poly(1,1,1-kifluoropropylmethyl-dimethy1) siloxane as a soft segment and 4,4'-dicyclohexyl methane diisocyanate(H-MDI) and then 4,4'-methylenebis(cyclohexyl amice)Pl-DAM) as a hard segment in a mixed solvent system of THFINMP. It was found that there was THF/NMP mixture ratio to dissolve the copolymers according to the variations of siloxane content and F/O composition. The effects of the siloxane content, molecular weight, block length and the composition upon the mechanical properties were investigated. It was shown that the mechanical properties related to the degree of phase mixing of hard segment and soft segment.

  • PDF

Physicochemical Composition of Head-Type Kimchi Cabbage Leaves (결구배추 잎의 이화학적 성분 조성)

  • Seong, Gi-Un;Hwang, In-Wook;Chung, Shin-Kyo
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.45 no.6
    • /
    • pp.923-928
    • /
    • 2016
  • To increase the consumption of head-type kimchi cabbage leaves as fresh food ingredients, the physicochemical composition was investigated depending on leaf parts. Kimchi cabbage leaves were divided into three portions, such as outer (L1), mid (L2), and inner (L3), and their proximate compositions were determined along with dietary fiber, free sugar, organic acid, free amino acid, and mineral contents. Contents of moisture, crude protein, and crude fat were highest in L1, whereas contents of crude ash and carbohydrate were highest in L3 (P<0.05). Calories ranged 24.5~26.5 kcal/100 g with no significant difference among leaf parts, and dietary fiber content of L1 was highest (P<0.05). Fructose, glucose, and sucrose contents were highest in L3 (P<0.05). Citric acid, malic acid, and succinic acid were detected, and contents of citric acid and malic acid were highest in L3, in contrast, succinic acid was highest in L1 (P<0.05). Glutamic acid, constituting over 30% of the total free amino acid contents, was highest in L3, whereas ${\gamma}-aminobutyric$ acid contents were highest in L1 (P<0.05). K, Na, Ca, and Mg were the major minerals in head-type kimchi cabbage, and their contents showed no significant differences (P<0.05). It can be proposed that marketing of head-type kimchi cabbage as a fresh-cut vegetable could be enhanced due to the different quality characteristics of its leaf parts.

Effects of a Novel p.A41P Mutation in the Swine Myogenic factor 5 (MYF5) Gene on Protein Stabilizing, Muscle Fiber Characteristics and Meat Quality

  • Ryu, Youn-Chul;Lee, Eun-A;Chai, Han-Ha;Park, Jong-Eun;Kim, Jun-Mo
    • Food Science of Animal Resources
    • /
    • v.38 no.4
    • /
    • pp.711-717
    • /
    • 2018
  • Myogenic factor 5 (MYF5) plays an important role in regulating skeletal muscle fiber characteristics, consequently affecting meat production and quality. We identified a novel p.A41P mutation in exon1 of the porcine MYF5 gene by direct sequencing. The mutation was predicted to be destabilizing in protein structure based on the resultant amino acid substitution. We estimated the significant substitution effect of p.A41P on the energy stabilization of Myf5 protein structure. Then, we demonstrated that the mutation in Yorkshire population significantly affected muscle fiber type I composition (p<0.05), loin-eye area of lean meat content (p<0.05) and filter-fluid uptake of meat quality (p<0.01). Furthermore, dominant effects significantly influenced total muscle fiber number (p<0.05). This study suggests that the novel p.A41P mutation in porcine MYF5 may be a valuable genetic marker to affect the muscle fiber characteristics and consequently improve meat production quality and quantity.

Wear Properties of the Alumina Short Fiber Reinforced Tin-Bronze Matrix Composites manufactured by Hot Pressing (가압소결법으로 제조된 알루미나 단섬유 보강 청동기지 복합재의 마모특성)

  • Choi, Jun-Ho;Huh, Moo-Young
    • Transactions of Materials Processing
    • /
    • v.4 no.4
    • /
    • pp.398-409
    • /
    • 1995
  • The wear properties of the alumina short fiber reinforced tin-bronze matrix composites manufactured by hot pressing was studied at the room temperature and $350^{\circ}C.$ The wear loss of various specimens having different constituent and different density was examined by a pin-on-disc type wear testing machine. The results were discussed by the observation of the worn surface morphology and the analysis of the composition on the worn surfaces. Since the reinforced effect of the alumina fiber on the wear resistance was dependent on the strength of alloy matrix, the pressureless sintered composites having a lower matrix strength showed a marked increase in wear resistance by the fiber reinforcement. As the wear condition became severe, the fiber reinforcement was more effective. The delamination on the wear surface was observed in the pressureless sintered specimens having pores which are related to the initiation and the propagation of cracks. However, the wear mechanism acting on a big failure area was not found on the wear surfaces of the hot pressed specimens having a few pores.

  • PDF

Effect of Glass Fiber and Graphite on Wear Properties in Tin-Bronze Matrix Composites (유리섬유 강화 청동기지 복합재에서 마모특성에 미치는 유리섬유와 흑연의 영향)

  • 황순홍;김종국;허무영
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • /
    • pp.181-187
    • /
    • 1995
  • The effet of glass fiber and graphite on the wear properies in tin-bronze alloy matrix composites was studied by a pin-on-disk type wear testing machine. The results obtained from the wear test were analized by SEM observations of worn surfaces of pins and disks and EPMA composition measurments. The amount of wear was devreased as increasing the content of glass fiber in matrix, since the alloy matrix was reinforced by glass fibers. The wear mechanism of the matrix specimen without glass fibers was proved as the contact area delamination. Oxide layer formed on sliding surface led to the increasing wear resistance. Specimens containing graphite particles showed an lubrication effect to counter disks.

  • PDF

Preparation and Characterization of Actuator Based on Carbon Nanotubes/lonic Liquid (탄소나노튜브와 이온성 액체를 이용한 액추에이터 제조 및 특성연구)

  • Seo, Mi-Jeong;Jung, Yeon-Su;Lee, Jeong-Ah;Ahn, Hyeong-Joon;Lee, Joon-Seok;Jeong, Yeong-Jin
    • Textile Science and Engineering
    • /
    • v.48 no.1
    • /
    • pp.14-19
    • /
    • 2011
  • Actuators of ionic electro-active polymer were prepared using single walled carbon nanotubes (SWNTs), poly(vinylidene fluoride-heaxafluoropropylene) (PVdF-HFP) and an ionic liquid. The effect of the composition of the electrode layer on the characteristics of the actuator was examined. The actuators were very light, flexible and bent largely at low voltages (IV). Overall, the maximum bending angle decreased with increasing amount of PVdF-HFP. The response time was also dependent on the type of ionic liquid. The actuator prepared with l-ethyl-3 methylimidazolium tetrafluoroboratre ($EMIBF_4$) operated faster and deformed morc than the one prepared with I-butyl-3-methylimidazolium tetrafluoroboratre ($BMIBF_4$) owing to its high ionic conductivity. Measurements of the voltage-displacement revealed the actuator made trom $EMIBF_4$ to have better linearity (recoverability). The composite actuator prepared in this study has potential applications ranging from micro switches to a11ificial muscles, robotics, etc..

The structures and mechanical properties of unidirectionally solidified Al-Fe-Ni alloy (일방향응고시킨 Al-Fe-Ni 합금의 조직과 기계적 성질)

  • 김여원;신민교
    • Journal of the Korean Society of Marine Engineering
    • /
    • v.7 no.1
    • /
    • pp.79-90
    • /
    • 1983
  • The examination for the changes of structures and mechanical properties in directionally solidified Al-Fe-Ni alloys containing the small amount of Fe and Ni was carried out by the varying the composition and solidification rate R of alloy, provided that the temperature gradient was 80 .deg.C/cm. The result were obtained as follows. A) In proportion to the increase of the solidification rate (R), the crystallized phase of this alloy was changed from the Ribbon-type structure to the Rod-type structure. B) The strength was rapidly increased in the changing process of composite shape from the Ribbon-type to the Rod-type with the solidification rate (R) increasing. C) The fiber stress (${\sigma}^f$) and Young's modulus ($E_f$) calculated for the Rod-type structure were 220 kg/$mm^2$ and 11, 800 kg/$mm^2$ respectively, which were in good accord with the rule of Mixtures.

  • PDF

A Study on the Effect of Appearance of Chelate Resin Matrix and Its Chemical Composition on the Adsorption Ability of Heavy Metal Ions(I) -Graft Copolymerization of 2-Methyl-2-oxazoline onto Chloromethylpolystyrene- (Chelate Resin Matrix의 외관과 그 화학적 조성이 중금속 흡착능에 미치는 영향에 관한 연구(I) -2-Methyl-2-oxazoline의 Chloromethylpolystyrene에 대한 그라프트공중합-)

  • 유혜자;전동원
    • Textile Science and Engineering
    • /
    • v.25 no.3
    • /
    • pp.1-9
    • /
    • 1988
  • Polyethyleneimine type chelate resin was synthesized by graft copolymerization of 2-methyl-2-oxazoline onto crosslinked chloromethylpolystyrenes. Polymeric effect such as crosslinking ratio and crosslinking agent introduced to chloromethylpolystyrene resin matrix on the graft copolymerization was investigated. The addition of dimethylformamide as solvent to the graft system increased the degree of graft copolymerization and decreased the activation energy of graft copolymerization.

  • PDF

Effects of Composition on the Properties of UV-Cured Polyurethane Acrylates (자외선 경화 Polyurethane Acrylate의 물성에 미치는 조성의 영향)

  • 이동진;최재혁
    • Textile Science and Engineering
    • /
    • v.31 no.4
    • /
    • pp.286-292
    • /
    • 1994
  • UV- curable polyurethane acrylate prepolymers were synthesized from hexamethylene diisocyanate (HMDI). polyols(polypropylene oxitlc biol(PPG)/polytetramethylenc ether glycol(PTMG)/glycerinc(GL) (or ethylene glycol(EG). 2-hydroxyethyl acrylate(HEA), and dibutyl tin dilaurate as a catalyst. The effect of prepolymer type and overall composition of the prepolymerfdiluent on the properties of UV-cured polyurethane acrylate as a function of temperature are investigeted. The gel content of the UV-cured polyurethanc acrylates roached to about 9$0^{\circ}C$, within 1 sec curing. The storage modulus increased with increasing PTMG and GL(or EG) content in mixed polyol PPG/PTMC/GL(or EG). The UV-curried polyurethane acrylate films commonly have two main glass transition temperatures in thin temperature range of -10$0^{\circ}C$~14$0^{\circ}C$. The higher temperature Tg of sample A series almost unchanged around 5$0^{\circ}C$ regardless of the composition of PPC/PTMC. but the lower temperature Tg decreased with increasing PTMG content in PPG/PTMG. These two Tgs of sample B and C series based on PPG/PTHG/GL(or EG) were about talc same regardless of the composition of PTMG/GL(or EG) at the fixed content of PPG. The viscosity of UV-curable polyurethane acrylate decreased tlramatically with increasing trimethylolpropane triacrylate(TMPTA) content antral temperature. and the viscosity of UV-curable polyurethane acrylates containing 20wt% and above of TMPTA was given below 1000cps at $65^{\circ}C$.

  • PDF

Seasonal Variation in the Dietary Fiber, Amino Acid and Fatty Acid Contents of Porphyra yezoensis (채취시기별 방사무늬김(Porphyra yezoensis)의 식이섬유, 아미노산 및 지방산 함량 변화)

  • Shin, Dong-Min;An, Se-Ra;In, Seo-Kyoung;Koo, Jae-Geun
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.46 no.4
    • /
    • pp.337-342
    • /
    • 2013
  • Porphyra yezoensis is potentially an excellent source of dietary fiber, amino acids, and eicosapentaenoic acid (EPA) because this red seaweed is available in large quantities and is rich in polysaccharides, proteins, and n-3 fatty acids. This study determined the insoluble dietary fiber (IDF), soluble dietary fiber (SDF), neutral detergent fiber (NDF), acid detergent fiber (ADF), amino acid, and fatty acid contents of P. yezoensis harvested monthly from November 2011 to March 2012. The total dietary fiber (TDF) and IDF contents ranged from 27.2-34.9% and 18.5-26.9%, respectively, and were greater in March than November. The SDF content ranged from 4.9-8.4% and did not differ significantly during growth. Galactose and 3,6-anhydro galactose were the major sugars in IDF and SDF. The higher levels of galactose and 3,6-anhydro galactose in IDF might be due to associated porphyran-type polysaccharides. Mannose and xylose were also major sugars in IDF. The total amino acid contents decreased gradually from November to March. The total amino acid composition of Porphyra was dominated by alanine, glutamic acid, arginine, and aspartic acid. No significant changes in the fatty acid profile were observed throughout the study period. The dominant fatty acid during all seasons was EPA, which comprised as much as 50% of the total fatty acid content.