• Polymer Science and Technology
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• v.3 no.6
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• pp.465-474
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• 1992

지금까지 우리는 환상 단량체(cyclic monomer)를 이용한 macromonomer의 다양한 합성 방법론에 대해 고찰해 왔다. 리빙 개환 중합(iving ring-opening polymerization)이 좁은 분자량 분포 및 예견할 수 있는 well-defined 구조를 갖는 macromonomer들을 합성할 수 있는 최상의 방법임은 주지의 사실이다. 또한 이렇게 합성된 macromonomer들을 이용한 graft 공중합체의 합성은 이미 언급한 바와 같이 다방면에 사용되고 있다. 다음으로 중요한 점은 많은 과학자들이 과학적 용어(scientific term)의 사용에 있어서 사용자들에게 많은 혼돈을 주고 있다는 사실이다. 예를들면 macromonomer는 Macromer$^{(R)}$ 혹은 macromolecular monomer등과 같은 의미이지만 어느 한가지로 통일되지 못하고 사용되고 있는 실정이다. 덧붙이자면 macromonomer는 기능화된 고분자(functionalized polymer) 혹은 넓은 의미의 'telechelic polymer'의 범주에 속한다. 본래 telechelic polymer란 분자 말단에 두개의 반응성기를 갖는 고분자나 oligomer를 일컫는 말로서 기능성 고분자(functionalized polymer)의 범주에 속한다. 이러한 사실들을 고려해 볼때 macromonomer는 중합이 일어날 수 있는 반응성 기를 가진 기능성 고분자 혹은 telechelic 고분자이다. 또한 많은 사람들이 macroinitiator와의 상이점을 구별치 못하는 경우가 있다. 물론 macroinitiator는 보통 block 공중합체를 제조하는데 이용되고 있는 반면 macromonomer는 graft 공중합체 합성에 사용되는 고분자 또는 oligomer이다.

• Macromolecular Research
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• v.12 no.5
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• pp.512-518
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• 2004

We have synthesized a novel macromonomer of vinyl-terminated bifunctional polyurethane having a molecular weight of 37,000 g/mol and successfully applied it to the dispersion polymerization of methylmethacrylate(MMA). We verified the presence of the vinyl terminal group and the macromonomer grafted onto the poly(ethylene glycol)(PEG) block in the PMMA particles by using $^1$H and $\^$13/C NMR spectroscopies. Monodisperse PMMA microspheres that have good uniformity of 1.01 were prepared at 20 wt% macromonomer content; we investigated the characteristics of the PMMA particles in terms of their molecular weight, molecular weight distribution, size of the particles, thermal properties, and glass transition temperature. We have found that the synthesized polyurethane macromonomer is an effective stabilizer.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.86-88
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• 2006

The novel linear- (V-LUM) and cross-type macromonomers (C-VUM) of vinyl-terminated bifunctional polyurethane were synthesized and applied to the dispersion polymerization of styrene and MMA in ethanol. The existence of the vinyl terminal groups and the grafted macromonomer with styrene and PMMA was verified using 1H NMR and 13C NMR. Monodisperse polystyrene (PS) microspheres were successfully obtained above 15 wt % of macromonomer relative to styrene. The macromonomer can efficiently stabilize higher surface area of the particles compared to a conventional stabilizer, PVP. The grafting ratio of the PS calculated from 1H NMR linearly increased up to 0.048 with 20 wt % of the macromonomer and the high molecular weights (501,300 g/mol) of PS with increased glass transition and enhanced thermal stability were obtained. Furthermore, the stable and monodisperse PMMA microspheres having a weight-average diameter of $5.09{\mu}m$ and a good uniformity of 1.01 were obtained with 20 wt% L-VUM. The molecular weight increased, but the size of the PMMA particles decreased with the macromonomer concentration due to the increased stabilizing effect. The molecular weight of the PMMA was approximately two fold higher than that by a conventional PVP. The L-VUM acts as a reactive stabilizer, which gives polyurethane-grafted PS or PMMA with a high molecular weight. In addition, the XPS result showed that the C-PS (PS using the C-VUM) was anchored with a larger amount of PEG than that of the L-PS (PS using the L-VUM) on the particle surface. Thus, the reaction and stabilizing mechanism of the macromonomers for the formation of PS particles is proposed.

• Macromolecular Research
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• v.8 no.1
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• pp.44-52
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• 2000

Styrenic macromonomers with/without a silyloxy-functional group were synthesizedvia chain-end functionalization using 4-vinylbenzyl chloride as a terminating agent insec-butyllithium-initiated polymerization of styrene. The yields were 92 mol% for the silyloxy group and 88 mol% for the styrenic unit. Crystalline polystyrene-g-amorphous polystyrenes were synthesized by (η$^{5}$ -indenyl)-trichlorotitanium ((Ind)TiCl$_3$)-catalyzed copolymerizations of the macromonomers with styrene in the presence of methyl-aluminoxane (MAO) in toluene at 4$0^{\circ}C$. The macromonomer having $\alpha$, $\alpha$'-bis (4-[tert-butyldimethylsilyl-oxy]phenyl) group was also utilized for the preparation of a precursor of hydroxyl-functionalized syndio-tactic polystyrene. The obtained polymers were characterized by a combination of$^1$H, $^{13}$ C NMR spectroscopic, size exclusion chromatographic, and differential scanning calorimetric analysis. The (Ind)TiCl$_3$-catalyzed copolymerization of styrene with the macromonomer carrying the silyloxy functional group was found to be an efficient method to modify syndiotactic polystyrene without a great loss of physica] property by controlling the feud ratio of the macromonomer.

• Polymer(Korea)
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• v.26 no.1
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• pp.28-36
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• 2002

In this study, we synthesized novel thiophene derivatives by the protection of the carboxyl group of 3-thiophene acetic acid with differently substituted benzyl groups. While 3-thiophene acetic acid is not electro-polymerizable, the modified monomers can be easily electro-oxidized to form stable electroactive polymers. The protecting groups can be easily removed in the solid state and the desired reactive carboxyl group can be introduced on the polymer surface. SEM observations show that obtained polymer films show a very good film surface and homogeneous morphology on the Pt electrode. After introduction of macromonomer, FT-IR spectrum shows new absorption bands at 1650 and $1550 cm^{-1}$, which is consistent with the formation of an amide bond. Electroactivity measurements were examined by cyclic voltammogram(CV). These polymers showed the characteristic electrochemical behavior of poly(3-alkylthiophene)s with reversible redox transition in the range of 0.7-0.9 V.

• Polymer Science and Technology
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• v.3 no.4
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• pp.275-284
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• 1992

지금까지 우리는 환상 단량체들을 이용한 macroinitiators 및 이들을 이용한 block 고중합체들의 합성방법론에 대해 고찰해 보았다. 이 방법들 중 living polymerization은 block 공중합체의 합성 뿐 만아니라 macroinitiator와 같은 기능성화된 고분자 합성을 위한 최적의 방법이다. 여기서 우리가 지적하고 싶은 것은 macroinitiator라는 과학적인 의미의 혼돈이다. 특히 macroinitiator와 macromolecular initiator는 같은 scientific terms들로서 혼돈이 있어서는 안되며 macroazoinitiator 역시 azo group을 가진 macromolecular initiator의 한 종류이다. 또한 macroinitiator와 macromonomer를 혼돈해서는 안되며 macroinitiator는 block 그리고 macromonomer는 graft 공중합체 및 Network 고분자 제조에 각각 이용되는 기능성화된 고분자(functionalized polymer) 혹은 oligomer를 의미한다.

• Macromolecular Research
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• v.15 no.4
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• pp.337-342
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• 2007

The n-butyllithium-initiated ring-opening polymerization of ethylene oxide, in a mixture of benzene and dimethylsulfoxide (DMSO), between $25-45^{\circ}C$, with potassium tert-butoxide, is a useful and powerful method to control the molecular weight as well as achieve a quantitative chain-end functionalization yield of the resulting polymeric alkoxide via a one pot synthesis. The molecular weight of the product could be controlled by adjusting the ratio of grams of monomer to moles of initiators, such as n-butyllithium ([n-BuLi]) and potassium t-butoxide ([t-BuOK]). The yields for the macromonomer and ${\omega}-brominated$ poly(ethylene oxide) (PEO) were quantitative in relation to the chain-end functionalizations of the polymeric alkoxide formed. The resulting products were characterized by a combination of $^1H-NMR$ spectroscopic and size exclusion chromatographic analyses.

• Biomaterials and Biomechanics in Bioengineering
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• v.2 no.2
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• pp.97-109
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• 2015

A series of amphiphilic graft copolymers were synthesized by varying the number of graft chains and graft chain lengths. The polarity of the hydrophobic graft chain on the copolymers was varied their solution properties. The glass transition temperature of the copolymers was in the low-temperature region, because of the amorphous nature of poly (trimethylene carbonate) (PTMC). The surface morphology of the lyophilized colloid gel had a bundle structure, which was derived from the combination of poly(N-hydroxyethylacrylamide)( poly(HEAA)) and PTMC. The solution properties were evaluated using dynamic light scattering and fluorescence measurements. The particle size of the graft copolymers was about 30-300 nm. The graft copolymers with a higher number of repeating units attributed to the TMC (trimethylene carbonate) component and with a lower macromonomer ratio showed high thermal stability. The critical association concentration was estimated to be between $2.2{\times}10^{-3}$ and $8.9{\times}10^{-2}mg/mL$, using the pyrene-based fluorescence probe technique. These results showed that the hydrophobic chain of the graft copolymer having a long PTMC segment had a low polarity, dependent on the number of repeating units of TMC and the macromonomer composition ratio. These results demonstrated that a higher number of repeating units of TMC, with a lower macromonomer composition, was preferable for molecular encapsulation.

• Applied Chemistry for Engineering
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• v.8 no.4
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• pp.673-678
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• 1997

Associative acrylic thickeners were prepared by emulsion copolymerization using nonionic vinyl surfactant esters as an associative macromonomer and their rheological properties were investigated. The thickening efficiency was shown to depend on the chain length of therminal hydrophobe and degree of ethoxylation of VSE. increasing the content of VSE enhanced the efficiency of the resulting polymers as a thickener. It was attributed to the intermolecular association of terminal hydrophobes of associative thickener in aqueous solution. The chain transfer agent caused to reduce the molecular weight of associative thickener, resulted in decrease of thickening efficiency.

• Clean Technology
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• v.5 no.2
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• pp.37-44
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• 1999

The influence of the reactant composition on the surface free energy and on the dispersity in water was investigated by using the fluorine-containing water-soluble polyurethane synthesized with the fluorine-containing diol and hydrophilic diol. The diol donating ionic characteristics was more effective than polyol, and stable emulsion with the diameter of 610~310 nm was obtained in the range of 0.3~0.7 molar ratio of the diol to polyol. According to the increment of fluorine-containing compound up to 10 wt %, the surface free energy of polyurethane was dramatically decreased from 22.3 to 12.6 dyn/cm, and the diameter of water dispersed polyurethane increased from 380 to 860 nm due to the strong interaction between polymer molecules because fluorine segments are arranged on the surface of molecules. The macromonomer with perfluoroalkyl group was more effective in complement of the weak point of water-soluble polyurethane, which is a decrease of hydrophobicity, because of strong hydrophobicity.