• Biotechnology and Bioprocess Engineering:BBE
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• 제10권3호
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• pp.230-235
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• 2005

For the acellular pertussis vaccine with a high immunogenicity, the concentration, composition and characteristics of acellular pertussis antigens are the crucial points to be considered. Nevertheless, it has not been proved yet whether or not the polymerization degree, one of the characteristics of formalin-detoxified acellular pertussis antigens, has an influence on vaccine potency. Thus, in the present study, the correlations among detoxification conditions of acellular pertussis bulks, their polymerization degrees and their immunogenicities were examined. In addition, the relative importance of pertussis toxoid in vaccine immunogenicity was also investigated. Results show that a lower lysine concentration during detoxification induces highly-polymerized antigens, the immunogenicity has a great dependency on the polymerization degree of antigens, and also pertussis toxoid has a relatively stronger influence on the immunogenicity than other antigens. Accordingly, in the aspect of the potency of detoxified acellular pertussis vaccine, it can be demonstrated that the polymerization of antigens and its degree are the major factors affecting the immunogenicity along with a relatively high content of pertussis toxoid

• 한국결정학회:학술대회논문집
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• 한국결정학회 2002년도 정기총회 및 추계학술연구발표회
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• pp.53-53
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• 2002

Alkali-soluble random copolymer (ASR) was used as a functional resin in the emulsion polymerization of styrene to prepare structured nanoparticles. The calorimetric technique was applied to study the kinetics of emulsion polymerization of styrene using ASR and conventional ionic emulsifier, sodium dodecyl benzene sulfonate (SDBS). ASR could form aggregates like micelles and the solubilization ability of the aggregates was dependent on the neutralization degree of ASR. The rate of polymerization in ASR system was lower than that in SDBS system. This result can be explained by the creation of a hairy ASR layer around the particle surface, which decreases the diffusion rate of free radicals through this region. Although a decrease in particle size was observed, the rate of polymerization decreased with increasing ASR concentration. The higher the concentration of ASR is, the thicker and denser ASR layer may be, and the more difficult it would therefore be for radicals to reach the particle through this layer of ASR. The rate of polymerization decreased with increasing the neutralization degree of ASR. The aggregates with high neutralization of ASR are less efficient in solubilizing the monomer and capturing initiator radicals than that of the lower neutralization degree, which leads to decrease in rate of polymerization.

• 한국전기전자재료학회논문지
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• 제27권12호
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• pp.847-851
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• 2014

The characteristics of dielectric constant and $tan{\delta}$ of low viscosity silicone oils with changing degree of polymerization were investigated. The result shows dipole loss mechanism at low temperature range. The dielectric loss in the range of low frequencies are predominantly of ionic nature with temperature increase. The peak of dielectric loss is the detrapping of the electrons which is were trapped in the localized level of the silicone oils at the frequency of 30 kHz. The increase of ionic conduction is attributed to the presence of ionizable oxidation products and their increased dissociation feature. The activation energy ${\Delta}H$ and dipole moment ${\mu}_d$ were increased whit increasing degree of polymerization.

• 대한치과기공학회지
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• 제29권2호
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• pp.9-15
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• 2007

As the development of nanotechnology, the use of composite resins which containing nanofillers becomes popular. The purpose of this study was to test the degree of polymerization of nanofillercontaining composite resins. For the study, three different nanofiller-containing composite resins and two different light-curing units were used. To evaluate the degree of polymerization, the maximum polymerization shrinkage taking place during the light curing, and the microhardness, after the light curing, were measured. As results, two light-curing units exhibited a similar emission spectrum to that of the included photoinitiator, camphorquinone. The only difference between the light-curing units were the width of the emission spectrum. Three different composite resins showed different microhardness values. Among them, Grandio showed the greatest microhardness value. However, there was less microhardness difference on the top and bottom surfaces due to the difference of the light-curing units. The maximum polymerization shrinkage values were also similar in the tested specimens regardless of the difference of the light-curing units. However, Grandio showed the least polymerization shrinkage. According to the manufacturers' data, Grandio showed the highest filler content(vol%).

• 한국표면공학회지
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• 제29권6호
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• pp.739-744
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• 1996

Lanthanide diphthalocyanines have interesting properties on electrochemical and chemical redox reactions. It is however, difficult to use because of thier short device life. Plasma-polymerization attends to improvement thier device life. Yb-diphthalocyanine ($YbPc_2$) polymer film was deposited in a parallel plate electrodes-type RF plasma reactor. $YbPc_2$ was sublimed into the argon plasma, and polymer film was obtained on a substrate. Radio frequency was constant of 13.56MHz. Pressure of argon gas, sublimation rate of $YbPc_2$ and RF power were variable parameters depending on film quality. Surface of polymer films include a lot of sub-micron order lumps. It was indicated that size of lumps depends on polymerization degree controled by parameters. Size of lumps and polymerization degree are increased with RF power. However, by the high RF power over 40W, polymerization degree is decreased with RF power and surface of film is rough. In condition of RF power is high, polymerization will compete with etching of film. We obtained good films for electrochromic display with RF power of 20W, argon gas pressure of 8.0 Pa and sublimationrate of $1.2 \times 10$ mol/min, and good films for gas sensor with RF power of 30W, argon gas pressure of 10.6Pa and sublimation rate of $1.2 \times 10$ mol/min.

• 대한소아치과학회지
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• 제26권2호
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• pp.296-309
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• 1999

가철성 상교정 장치에 많이 사용되는 자가중합형 상교정용 레진의 미반응 단량체는 레진의 물성과 생물학적인 면에 많은 영향을 끼친다. 따라서 미반응 단량체를 최소화하고 중합률을 최대로 하는 중합방법에 대한 연구는 중요한 의의를 갖는다. 저자는 자가중합형 상교정용 레진의 중합시간과 중합방법에 따른 중합률을 비교해보기 위해 시편을 다음과 같이 5군으로 나누어 연구를 진행하였다. 상교정용 레진의 분말과 용액을 혼합하여 제 1군은 $28^{\circ}C$의 공기중에 보관하였고, 제 2군은 $28^{\circ}C$의 물에, 제 3군은 $28^{\circ}C$의 물과 30psi의 압력에, 제 4군은 $43^{\circ}C$의 물에, 제 5군은 $43^{\circ}C$의 물과 30psi의 압력하에 각각 보관하였고, 10분, 1시간, 12시간, 1일, 3일 경과 후에 각 시편을 Fourier 변환적외선분광법을 이용하여 중합률을 측정하여 다음과 같은 결론을 얻었다. 1. 모든 군에서 중합시간이 경과함에 따라 중합률도 지속적으로 증가하는 양상을 보였다. 10분 경과 후의 결과와 비교하여 볼 때, 제 1군은 12시간 경과 후부터 중합률의 증가가 유의성이 있었고, 제 2군과 3군, 4군, 5군은 1시간 경과 후부터 유의성이 있었다(p<0.05). 2. 10분과 1일, 3일 경과 후에 제 5군, 제 4군, 제 3군, 제 2군, 제 1군의 순서대로 중합률이 높았다. 3. 중합시 온도에 따른 비교에서, 1일 경과 후를 제외하고는 모든 시간에서 $43^{\circ}C$에서 중합시킨 군의 중합률이 $28^{\circ}C$에서 중합시킨 군의 중합률 보다 유의성 있게 높았다(p<0.05). 4. 압력은 12시간 경과 후를(p<0.05) 제외하고는 중합률에 영향을 주지 못했다. 5. 보관방법은 1시간 경과 후를(p<0.05) 제외하고는 중합률에 영향을 주지 못했다.

• 한국의류학회지
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• 제20권5호
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• pp.905-914
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• 1996

To study the effect of the bleaching agents in detergents on the degradation of cotton fabrics, the carboxyl contents, copper numbers, degree of polymerization, the change of tensile strengths and fiber surfaces of cotton fabric before and after washing were examined. The results obtained were as follows: As the cycles and temperature of washing increased, the carboxyl content of washed cotton fabric changed little but the copper unmber of cotton fabric was increased. At 6$0^{\circ}C$ , 8$0^{\circ}C$ the copper number of cotton fabric washed with soidum perborate (PB) was higher than that of with sodium percarbonate (PC). The degree of polymeriazation and tensile strength of cotton fabric were decreased and at higher temperature those were more decreased but were less decreased when tetraacetyehylenediamine (TAED) was added. The degree of polymerization had negative relation with copper unmber but with tensile strength of cotton fabric had positive relation. Cotton fiber surface was more degraded by bleaching agents and hydrogen peroxide exhaustion was increased as the temperature of washing increased. And hydrogen peroxide exhaustion had negative relation with the degree of polymerization.

• 대한화학회지
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• 제6권1호
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• pp.19-24
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• 1962

In the emulsion polymerization of vinyl acetate with Triton-X(Alkyl-aryl-polyether alcohol) and polyvinyl alcohol as emulsifier, some relations between the conditions of polymerization and the polymerization rate, polymerization degree and stability of the emulsion are studied and discussed.

• 한국치위생학회지
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• 제9권3호
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• pp.369-379
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• 2009

This study investigated the polymerization inhibition effect of latex gloves on addition silicone impression material. Three different kinds of addition silicone impression materials and a natural latex gloves were used in this study. The results were as follows. 1. Compared to the control group, all of those three kinds of impression materials took longer curing time in order of unwashed, alcohol and washed group, on the other hand, degloving group had shorter curing time than control group(p<0.05). 2. By the type of impression materials, there was no significant difference observed between Exafine and Twinz in ungloved group, Exafine and Imprint II in unwashed group, and Exafine and Twinz in degloving group(p>0.05). 3. The degree of polymerization at 6 minutes after mixing impression materials was evaluated by dividing its range into score 1 to 5. All of the impression materials got score 5 in control group and degloving group, which implies perfect polymerization. In unwashed group, most of them appeared to be score 2 while score 3 were most frequently observed in alcohol group and score 4 in washed group. Thus each group showed differences in the degree of polymerization(p<0.05).

• 한국자기공명학회논문지
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• 제20권1호
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• pp.7-12
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• 2016

PTMEG(Polytetramethylene ether glycol) is a polymer compound widely used as a wide range of applications in the textile industry. PTMEG substance carrying various 1,800~2,000 molecular weight are mainly used as the raw material of the spandex production. Molecular weight and degree of polymerization value for 4 different PTMEG samples under pilot plant scale synthetic process were determined by a new quantitative NMR method. In NMR experiments, p-toluenesulfonic acid(TSOH) was used for external standard material of PTMEG quantitative analysis. were measuring The concentration of the primary standard TSOH was measured by UV/Vis spectroscopy. By using NMR peak assignments and the integral values of designated proton NMR peaks, We were able to measure the % composition of the synthetic PTMEG polymers, concentrations, molecular weight and the degree of polymerization that show the synthetic process of each manufacturing pilot plant. By utilizing a newly developed quantitative NMR method were able to obtain the molecular weight of PTMEG samples within 0.08 error % range.