• 한국응용과학기술학회지
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• 제22권3호
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• pp.257-269
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• 2005

This study was focused on the maximization of flame-retardancy of polyesters by a synergism of simultaneously introduced chlorine and phosphorus into polymer chains of modified polyesters. To prepare modified polyesters, reaction intermediates, TD-adduct (prepared from trimethylolpropane /2,4-dichlorobenzoic acid (2,4-DCBA)) and TMBO (prepared from tetramethlene bis (orthophosphate)), were prepared first, then condensation polymerization of the prepared intermediates, adipic acid, and 1,4-butanediol were carried out. In the condensation polymerization, the content of phosphorus was fixed to be 2wt%, and the content of 2,4-DCBA that provides chlorine component was varied to be 10, 20, and 30wt%, and we designated the prepared modified polyesters containing chlorine and phosphorus as ABTTs. The prepared intermediates and modified polyesters were characterized with FT-IR, NMR, GPC, and TGA analysis. Average molecular weight and polydipersity index of the preparation of ABTTs were decreased with increasing 2,4-DCBA content because of the incease in hydroxyl group that retards reaction. We found that the thermal stability of the prepared ABTTs increased with chlorine content at high temperatures.

• 한국응용과학기술학회지
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• 제23권1호
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• pp.26-36
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• 2006

The aim of this study is to synthesis basic resins for the preparation of PU flame-retardant coatings that contain phosphorus and chlorine. After synthesizing intermediates of tetramethylene bis(orthophophate) (TMBO) and neohexanediol trichlorobenzoate (TBA-adduct), the condensation polymerization was performed with the intermediates, 1,4-butanediol, and adipic acid to obtain four-component copolymers. In the condensation polymerization, the content of phosphorus was fixed to be 2%, and the content of trichlorobenzoic acid (TBA) that provides chlorine component was varied to be 10, 20, and 30wt%, and we designated the prepared modified polyesters containing chlorine and phosphorus as TTBA-10C, TTBA-20C and TTBA-30C. Average molecular weight and polydispersity index of the prepared TTBAs decreased with increasing TBA content because of the increase in the number of hydroxyl groups that retards reaction. We found that the thermal stability of the prepared TTBAs increased with chlorine content at high temperatures.

• 한국응용과학기술학회지
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• 제24권4호
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• pp.319-331
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• 2007

The aim of this study is to enhance the flame retardancy by the synergism effect of phosphorus and bromine groups. The flame-retardant polyurethane coatings containing phosphorus and bromine compounds were synthesized. After synthesizing the intermediate products of tetramethylene bis(orthophosphate) (TBOP) and trimethylolpropane/2,3-dibromopropionic acid (2,3-DBP) [2,3-DBP-adduct], the condensation polymerization was performed with four different monomers of two intermediate products, 1,4-butanediol, and adipic acid to obtain four-components copolymer. In the condensation polymerization, the content of phosphorus was fixed to be 2wt%, and the content of 2,3-DBP that provides bromine component was varied to be 10, 20, and 30wt%, and we designated the prepared modified polyesters containing phosphorus and bromine as DTBA-10C, -20C, -30C. Average molecular weight and polydispersity index of the preparation of DTBAs were decreased with increasing 2,3-DBP content because of increase of hydroxyl group that retards reaction. We found that the thermal stability of the prepared DTBAs increased with bromine content at high temperature.

• 한국응용과학기술학회지
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• 제34권2호
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• pp.203-209
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• 2017

양이온계 광중합에 적용 가능한 propenyl ether 형태의 단량체들을 mono 및 di-functional alcohol과 allyl bromide의 축합반응으로 합성하였다. 이들 단량체들을 양이온 광개시제와 혼용하여 코팅조성물을 제조하여 광경화 반응성을 조사하였다. 그 결과 mono propenyl ether 형태인((prop-1-en-1-yloxy)methyl)benzene (POMB)는 dipropenyl ether 계인 1,4-bis(prop-1-en-1-yloxy) benzene (BPOB) 비교하여 초기 중합 속도는 10.2로 상대적으로 낮게 나타났으나 1.5mol%의 광개시제를 포합한 배합물에서는 90초이내에 거의 정량적으로 반응하였다. 또한 긴알킬기를 갖는 술폰산 염계 광개시제들은 단량체들에 빠른 용해 특성을 나타내었고 산성도가 높은 광개시제인(4-n-decyloxyphenyl)diphenylsulfonium hexafluoroantimonate(DPSA)와 (4-n-decyloxyphenyl) diphenylsulfonium triflate (DPST)를 사용한 경우 비교적 높은 중합속도와 전환율을 나타내었다.

• 멤브레인
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• 제20권4호
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• pp.297-303
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• 2010

폴리올레핀 중합공정에서 발생되는 미반응 올레핀 모노머를 회수하기 위한 분리막/냉각응축 공정에 적용할 복합막을 용액 코팅공정과 플라즈마 중합공정의 두가지 방법으로 제조하였다. Polysulfone (PSF) 지지체 위에 poly(dimethylsiloxane) (PDMS) 용액을 코팅하였고 코팅 용액에서 prepolymer의 함량이 높을수록 올레핀 모노머의 선택도는 증가하였으나 막이 치밀하여지는 관계로 절대 투과량은 감소하는 경향을 보였다. 유기물의 복합막 투과는 용액확산 메커니즘에 의한 것으로서 임계온도가 높을수록 분리효율은 향상되고 molar volume이 증가할수록 투과도가 향상되었다. 또한 가교시간에 siloxane 계열의 물질을 plasma 종합하여 복합막을 제조하였는데 PSF 및 polypropylene (PP) 지지체를 사용하였다. 특히 지지체로 기존의 용액코팅 공정에서 사용되기 어렵던 PP 지지체 위에도 복합막을 코팅할 수 있었으며 용액코팅 공정으로 제조된 복합막과 유사한 성능을 나타내었다.

• 폴리머
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• 제26권4호
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• pp.439-444
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• 2002

n-Alkyloxy기를 가지는 4가지 종류의 서로 다른 benzilidene anhydrides (2a~d)를 4-(n-alkyloxy)benzaldehyde (1a,b)와 diethyl succinate와의 Stobbe condensation, 가수분해, 탈수고리화반응으로 이어지는 연속적인 반응을 통하여 성공적으로 합성하였다. 단량체의 화학적 구조를 분광학적 방법으로 분석하여 합성된 단량체 (2a~d)는 (Z,Z)-이성체로 존재함을 확인하였다. 중합은 질소분위기하 150~$210^{\circ}C$의 온도범위에서 괴상중합법으로 행하여졌다. 합성된 고분자의 화학적 구조와 열적 성질을 각각 분광학적 방법과 TGA, DSC를 이용하여 조사하였다. 합성된 고분자의 성질은 곁사슬의 길이에 따른 화학적 구조에 크게 의존함을 알 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제18권3호
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• pp.318-323
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• 1997

ο-(2-Vinyloxyethoxy)benzylidenemalononitrile (3a) and methyl ο-(2-vinyloxyethoxy)-benzylidenecyanoacetate (3b), m-(2-vinyloxyethoxy)benzylidenemalononitrile (4a), and methyl m-(2-vinyloxyethoxy)benzylidenecyanoacetate (4b) were prepared by the condensation of ο-(2-vinyloxyethoxy)benzaldehyde (1) and m-(2-vinyloxyethoxy)benzaldehyde (2) with malononitrile or methyl cyanoacetate, respectively. Bifunctional vinyl ether monomers 3a and 3b polymerized quantitatively with radical initiators in γ-butyrolactone solution at 65 ℃, while meta-isomers 4a and 4b gave lower yields of polymers under the same conditions. The polymers 5-6 obtained from the monomers 3-4 were insoluble in common solvents due to cross-linking. Under the same polymerization conditions ethyl vinyl ether polymerized well with model compounds ο-methoxybenzylidenemalononitrile 7a, methyl ο-methoxybenzylidenecyanoacetate 7b, m-methoxybenzylidenemalononitrile 8a, and methyl m-methoxybenzylidenecyanoacetate 8b, respectively, to give 1:1 alternating copolymers 9-10 in high yields. Cross-linked polymers 5-6 showed a thermal stability up to 300 ℃, and showed a double phase degradation pattern in their TGA thermograms. Polymers 5-6 showed broad endothermic bands around 75-110 ℃ without any characteristic Tg peaks in DSC thermograms. Alternating copolymers 9-10, except copolymer 9b were soluble in common organic solvents. The inherent viscosities of polymer 9-10 were in the range of 0.35-0.62 dL/g. Polymer films cast from acetone solution were cloudy and tough and Tg values obtained from DSC thermograms were in the range of 118-165 ℃.

• 한국실내디자인학회논문집
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• 제17권1호
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• pp.30-38
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• 2008

Borrowed landscape is an Oriental gardening method to draw inside external natural landscape, and borrowed landscape of Japan has a different characteristic from that of Korea or China nature is manipulated and re-interpreted by human will in the course of applying it to architectural space. In other words, not the original scenery, but manipulated one appears which is cut, reduced, or deleted by architectural elements such as wall, window, or fence. Therefore, this study examined how architectural structure of Ando Tadao symbolizing modernist architecture understood and adopted Japanese traditional views on nature, that is, borrowed landscape. To this end, on the basis of the understanding on 'polymerization of abstraction and form' he mentioned, his geometric architectural principles are discussed, since this serves to be an important beginning of architectural concretization by the concept of 'form' experienced and perceived by human being through geometric means called architecture 'abstraction.' The findings of this study are as follows: first, it was found that Ando Tadao generates borrowed landscape effects by polymerizing and manipulating his simple and geometric structures with each other and thereby editing natural scenery, while Japanese traditional borrowed landscape introduces source scenery inside, through condensation and symbolization. Second, the results of this study revealed that his architecture functions to transcend external and internal realm of a space, which is also observed in Japanese traditional architectural borrowed landscape. Therefore, this study is considered significant in the sense that it proved that Ando Tadao's architectural language is based on borrowed landscape as a specific Japanese traditional element, going beyond the scope of previous studies focusing simply on the introduction of natural elements.

• Carbon letters
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• 제25권
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• pp.95-102
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• 2018

We examined the pressure effects on petroleum pitch synthesis by using open and closed reaction systems. The pressure effects that occur during the pitch synthesis were investigated in three pressure systems: a closed system of high pressure and two open systems under either an atmosphere or vacuum. A thermal reaction in the closed system led to the high product yield of a pitch by suppressing the release of light components in pyrolysis fuel oil. Atmospheric treatment mainly enhanced the polymerization degree of the pitch via condensation and a polymerization reaction. Vacuum treatment results in a softening point increase due to the removal of components with low molecular weights. To utilize such characteristic effects of system pressure during pitch preparations, we proposed a method for synthesizing cost-competitive pitch precursors for carbon materials. The first step is to increase product yield by using a closed system; the second step is to increase the degree of polymerization toward the desired molecular distribution, followed by the use of vacuum treatment to adjust softening points. Thus, we obtained an experimental quinoline insolubles-free pitch of product yield over 45% with softening points of approximately $130^{\circ}C$. The proposed method shows the possibility to prepare cost-competitive pitch precursors for carbon materials by enhancing product yield and other properties.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 봄 학술발표회 논문집
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• pp.335-336
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• 2003

The synthesis of poly(trimethylene terephthalate) (PTT), whose application is being expanded very rapidly to new apparel and carpet materials, was investigated by melt condensation polymerization using 1,3-propanediol (PDO) and terephthalic acid (TPA). No catalyst was used in the 1st step reaction (esterification), but tetrabutyl titanate(TBT) was used as a polyesterification catalyst ranging from 25 to 75 ppm based on the weight of TPA used in the 2nd step reaction (polyesterification). The molar ratio of PDO to TPA was set as 2.2:1. The effect of reaction conditions on the color and intrinsic viscosity of the final product was investigated. (omitted)