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Kwang Ho Sohn Min Kwan Kim So Min Lee Byung Chul Ji Kwang Soo Cho Kyungmoon Jeon Han Do Ghim 《Fibers and Polymers》2011,12(4):451-456
Triphenyl phosphate (TPP) is well known to be one of the most effective flame retardants for acrylonitrile-butadiene-styrene
copolymer (ABS) and its blending resins, such as polycarbonate (PC)/ABS, among various phosphorous-based compounds. However,
TPP can also play a role as a plasticizer, which decreases the mechanical properties of PC/ABS resins at high temperature.
Furthermore considerable amount of TPP has to be evaporated during molding process due on its much lower evaporation temperature.
To overcome these shortcomings, we tried to immobilize TPP by grafting on butadiene moiety of ABS. FT-IR analysis of prepared
TPP-grafted ABS (ABS-g-TPP) comparing with TPP, ABS and their blend confirmed that chemical reactions happened between TPP
and ABS resins and it was attributed to the graft reaction of TPP onto butadiene moieties. Prepared ABS-g-TPP resins were
blended with PC at various compositions to be prepared as testing specimens by injection molding. The physical characteristics
such as mechanical properties, thermal stability, and flame retarding properties of the PC/ABS-TPP graft copolymer were analyzed
through Vicat softening temperature, IZOD impact strength, transmission electron microscope, and UL94 flame retardation tests.
Results showed that PC/ABS-g-TPP resin takes better thermomechanical properties than the existing PC/ABS resins at relatively
low additional TPP amounts. 相似文献
2.
Sung Ok Sohn So Min Lee Yun Mi Kim Jeong Hyun Yeum Jin Hyun Choi Han Do Ghim 《Fibers and Polymers》2007,8(2):163-167
A durable aroma finishing for PET fabric was carried out by adopting poly(vinyl acetate) (PVAc) nanoparticles containing lavender
oil (LO) in core. Relatively small size of PVAc nanoparticles (ca. 244 nm of mean particle diameter) was expected to resist
the frictional destruction of the particles, which is frequently observed in cases of microcapsules. PVAc nanoparticles containing
LO in core were prepared by emulsification-diffusion method and their application as an aroma releasing agent for PET fabrics
was assessed through the observation of releasing profiles of LO in ethanol for experimental acceleration. Melamine-formaldehyde
(MF) microcapsules containing LO were also prepared and treated on fabrics for comparison. PVAc nanoparticles treated on PET
fabric showed higher initial releasing amount, which was ascribed to the enhanced surface area. After 2 days of releasing,
PET fabric treated with PVAc nanoparticles showed slower and more stable releasing profile and reached about 12 ppm of cumulative
release after 16 days, which was under two thirds of that with MF microcapsules. PVAc nanoparticles can be used as an agent
for durable aroma finishing of PET fabrics. 相似文献
3.
Kim Sam Soo Leem Su Gyung Ghim Han Do Kim Joon Ho Lyoo Won Seok 《Fibers and Polymers》2003,4(4):204-209
The effect of padding solution on the microwave heat dyeing of polyester fabric was studied extensively. Polyester fabrics
were impregnated in aqueous urea solution and aqueous sodium chloride solution for 10 min and then dyed for 7 min by microwave
apparatus (2 450 MHz, 700 W) under optimum conditions which provide good exhaustion. Aqueous solutions of urea and sodium
chloride showed more effective than water as a padding solution for microwave heat dyeing. The type of solvent added in padding
media and its concentration significantly affects the K/S values of dyed polyester fabric. Added solvents such as n-hexane,
acetone, and dimethyl formamide were also more effective than 100% water as padding media for the microwave heat dyeing. It
is supposed that the effect of used solvents on dyeing property of polyester fabrics depends on the solubility parameter difference
between solvent and polyester fabric. 相似文献
4.
Hye Min Jung Eun Mi Lee Byung Chul Ji Sung Ok Sohn Han Do Ghim Hyunju Cho Young A Han Jin Hyun Choi Jae Deuk Yun Jeong Hyun Yeum 《Fibers and Polymers》2006,7(3):229-234
Poly(vinyl acetate) (PVAc)/poly(vinyl alcohol)(PVA)/montmorillonite (MMT) clay nanocomposite microspheres with a core/shell
structure have been developed via a suspension polymerization approach. In order to prepare the PVAc/MMT and PVAc/PVA/MMT
nanocomposite microspheres, which are promising precursor of PVA/MMT nanocomposite microspheres, suspension polymerization
of vinyl acetate with organophilic MMT and heterogeneous saponification were conducted. A quaternary ammonium salt, cetyltrimethylammonium
bromide, was mixed with the MMT in the monomer phase prior to the suspension polymerization. The rate of conversion decreased
with an increase in MMT concentration. The incorporation of MMT into the PVAc was verified by FT-IR spectroscopy. Organic
vinyl acetate monomers were intercalated into the interlayer regions of organophilic clay hosts and followed by suspension
polymerization. Partially saponified PVA/MMT nanocomposite microspheres with a core/shell structure were successfully prepared
by heterogeneous saponification. 相似文献
5.
In this paper we investigated the human thermoregulatory responses, especially core temperature behavior during exercise and
recovery at ambient temperature of 10 °C and 50 % R.H. under the conditions of wearing three kinds of clothing with same weight
and different constructions. Six healthy men wore three kinds of clothing: one insulating the upper half of the body thinly
and the lower half of the body heavily (clothing A, the weights in the upper and lower halves of the body were 489 g and 1278
g, respectively.), the second one insulating the upper half of the body heavily and the lower half of the body thinly (clothing
B, 1212 g and 559 g, respectively.), and the third one insulating the upper and lower halves of the body moderately (clothing
C, 899 g and 879 g, respectively.). The level of rectal temperature was the greatest during exercise in clothing C and the
lowest during recovery in clothing A. The increasing and decreasing rates of core temperature during exercise and recovery,
respectively, were the smallest in clothing B. These findings are discussed in terms of different cooling efficiency from
the lower extremities and disfunction of counter current heat exchange system among clothing A, B, and C. 相似文献
6.
J. Y. Kim Y. S. Ghim S. B. Lee K.-C. Moon S.-G. Shim G. N. Bae S.-C. Yoon 《Water, air, and soil pollution》2010,205(1-4):259-272
The amounts of nitrogen and sulfur deposited in the region of the Yellow Sea in both dry and wet forms were estimated focusing on the period between 1999 and 2000. Dry deposition fluxes were obtained using concentrations from ground stations on both Korean and Chinese sides and from shipboard and aircraft measurements. Wet deposition fluxes were determined at ground stations on the Korean side. The dry deposition flux over the Yellow Sea was much greater than those for other world oceans. As a whole, the amounts of wet depositions of nitrogen and sulfur were 1.9 and 1.5 times larger than the amounts of respective dry depositions. Substantial influence from China caused by high emissions in East China and westerly wind was possibly suggested. However, the influence from nitrogen emission in Korea was also confirmed. 相似文献
7.
Won?Seok?LyooEmail author Seok?Kyun?Noh Jeong?Hyun?Yeum Gu?Chan?Kang Han?Do?Ghim Jinwon?Lee Byung?Chul?Ji 《Fibers and Polymers》2004,5(1):75-81
To obtain high molecular weight (HMW) poly(methyl methacrylate) (PMMA) with high conversion, methyl methacrylate (MMA) was
polymerized in suspension using a room temperature initiator, 2,2′-azobis(2,4-dimethylvaleronitrile) (ADMVN), and the effects
of polymerization conditions on the polymerization behavior of MMA and the molecular parameters of PMMA were investigated.
On the whole, the experimental results well corresponded to the theoretically predicted tendencies. These effects could be
explained by a kinetic order of ADMVN concentration calculated by an initial rate method and an activation energy difference
of polymerization obtained from the Arrhenius plot. Suspension polymerization at 25 °C by adopting ADMVN proved to be successful
in obtaining PMMA of HMW (number-average degree of polymerization (Pn): 30,900–36,100) and of high yield (ultimate conversion of MMA into PMMA: 83–93 %) with diminishing heat generated during
polymerization. The Pn and lightness were higher and polydispersity index was lower with PMMA polymerized at lower temperatures. 相似文献
8.
End-capping of PET with triphenyl phosphate (TPP), bisphenol A bis(diphenyl phosphate) (BDP), or resorcinol bis(diphenyl phosphate) (RDP) as phosphorous containing flame retardants was performed by using benzoyl peroxide as initiator. 31P NMR and FT-IR spectroscopy were used to evaluate end-capping of PET and structural changes of specimens. From thermal characteristics evaluated by differential scanning calorimetry and thermogravimetric analysis, BDP and RDP end-capped PETs show flame retarding mechanisms similar to those of blended counterparts. However, TPP end-capped PET presented superior carbonaceous char yields of up to 46.7 %, which was attributed to the condensed-phase action of TPP anchored at the ends of PET. 相似文献
9.
In order to prepare high molecular weight poly(methyl methacrylate) (PMMA)/silver nanocomposite microspheres, methyl methacrylate
was suspension-polymerized in the presence of silver nanoparticles at low temperature with 2,2′-azobis(2,4-dimethylvaleronitrile)
as an initiator. The rate of conversion was increased by increasing the initiator concentration. When silver nanoparticles
were added, the rate of polymerization decreased slightly. High monomer conversion (about 85 %) was obtained in spite of low
polymerization temperature of 30°C. Under controlled conditions, PMMA/silver microspheres with various number-average degrees
of polymerization (6,000–37,000) were prepared. Morphology studies revealed that except for normal suspension microspheres
with a smooth surface, a golf ball-like appearance of the microspheres was observed, due to the migration and aggregation
of the hydrophilic silver nanoparticles at the sublayer beneath the microsphere’s surface. 相似文献
10.
Rehtanz M Bossart GD Doescher B Rector A Van Ranst M Fair PA Jenson AB Ghim SJ 《Veterinary microbiology》2009,133(1-2):43-53
Papillomaviruses (PVs) have been shown as being the etiologic agents of various benign and malignant tumours in many vertebrate species. In dolphins and porpoises, a high prevalence of orogenital tumours has recently been documented with at least four distinct novel species-specific PV types detected in such lesions. Therefore, we generated the immunological reagents to establish a serological screening test to determine the prevalence of PV infection in Atlantic bottlenose dolphins [(Tursiops truncatus (Tt)]. Using the baculovirus expression system, virus-like particles (VLPs) derived from the L1 proteins of two TtPV types, TtPV1 and TtPV2, were generated. Polyclonal antibodies against TtPV VLPs were produced in rabbits and their specificity for the VLPs was confirmed. Electron microscopy and enzyme-linked immunosorbent assay (ELISA) studies revealed that the generated VLPs self-assembled into particles presenting conformational immunodominant epitopes. As such, these particles are potential antigen candidates for a TtPV vaccine. Subsequently, the VLPs served as antigens in initial ELISA tests using sera from six bottlenose dolphins to investigate PV antibody presence. Three of these sera were derived from dolphins with genital tumour history and showed positive PV ELISA reactivity, while the remaining sera from lesion-free dolphins were PV antibody-negative. The results suggest that the developed screening test may serve as a potential tool for determining PV prevalence and thus for observing transmission rates in dolphin populations as the significance of PV infection in cetaceans starts to unfold. 相似文献
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