• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.1-5
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• 2018

In this study, we designed and synthesized novel thermal radical initiators of BTAP (1-phenyl-3,3-dipropyltriazene), BTACP (1-(phenyldiazenyl)pyrrolidine), BTACH (1-(phenyldiazenyl)piperidine), and BTACH7 (1-(phenyldiazenyl)azepane) based on a triazene moiety to provide a thermal initiator for radical polymerization. The synthetic method is valuable due to the simplicity. In addition, the synthesized thermal initiator did not affect the color of the polymer. Among the four initiators, the polymerization time for the BTACH of the 6-membered ring decreased by 67%, as opposed to the polymerization time without initiator. Conversion after polymerization was over 92%. DSC experiments also showed that the initiator with hexagonal rings had the lowest peak polymerization temperature of $160^{\circ}C$. Our study suggests a promising new initiator system that is effective for radical polymerization.

• Archives of Pharmacal Research
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• v.6 no.1
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• pp.1-6
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• 1983

The reaction of ethylenecarbonate (I) with bromine was carried out in the presence of benzolperoxide as radical initiator. The following several different esters being ring opened were obtained; bromoacetyl-bromoformate, (1-hyroxy, 1, 2-dibromo)-ethyl bromoformate, (1-hydroxy, 1, 2, 2'-tribromo)diethylacarbonate, 2-bromoethyl-tribromoacetate, (1-acetoxy, 1'-bromomethyl)-bromomalo nate, 2-bromoethyl-bromoacetoxy-tribromoacetate.

• Macromolecular Research
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• v.15 no.4
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• pp.324-329
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• 2007

An octa-functional alkoxyamine initiator, with the 2,2,6,6-tetramethyl-l-piperidinyloxy (TEMPO) free radical, was synthesized based on resorcinarene, with its efficiency to initiate the nitroxide-mediated free radical copolymerization of styrene and methyl methacrylate (MMA) described. A difunctional analogue of this initiator was also synthesized, using resorcinol as the core molecule. The structures of the resulting initiators were confirmed by homolysis studies based on electron spin resonance spectroscopy and molecular modeling. The polymerization behavior and characteristics of the polymers obtained using these two initiators were also compared. Well-defined star-shaped and linear random copolymers, with low polydispersities and controlled molecular weights, were prepared. The efficiencies of these initiators towards copolymerization, as well as the parameters permitting the formation of well-defined polymers, were also investigated. The reactivity ratios were $r_a=0.42(a=styrene)\;and\;r_b=0.33(b=MMA)$ for the octa-functional initiator system and $r_a=0.45\;and\;r_b=0.39$ for the difunctional initiator system.

• Journal of the Korean Chemical Society
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• v.24 no.5
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• pp.398-403
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• 1980

Carboxyl-terminated polybutadiene was prepared by free-radical polymerization using 4,4'-azobis-[4-cyano valeric acid] as an initiator and the effect of initiator concentration on polymer properties was investigated. Polymerization of the carboxyl-terminated polybutadiene was carried out varying the initiator concentration reacting with a constant butadiene concentration. The carboxyl weight percent decreased with increasing initiator concentration. The conversion was proportional to the square root of initiator concentration, giving a functionality greater than 2.0 which is consistent with the general tendency of free radical polymerization.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1208-1211
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• 2004

When irradiated with visible light in HPDLC, photoinitiator and coinitiator produce a radical for photopolymerization. According to the kinds of photoinitiator and coinitiator, quantity and rate of produced a radical is different. It is influence on photopolymerization rate relate on diffraction efficiency. Thus, this paper is about the effect of photoinitiator/coinitiator combinations in terms of diffraction efficiency and real-time first order diffraction efficiency.

• Journal of the Korean Applied Science and Technology
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• v.26 no.3
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• pp.306-316
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• 2009

In this study, block copolymer of polystyrene and polyethylene glycol methyl ether methacrylate(PEGMA) by ATRP(atom transfer radical polymerization) method was synthesized. 4 arm-molecule which contained halogen atom was synthesized for an initiator. With 4 arm-molecule monodispered polystyrene were synthesized by ATRP method. The molecular change of synthesized monodispersed polystyrene with respect to time was investigated and living polymer characteristic was confirmed. Block copolymer of polystyrene and polyethylene glycol methyl ether methacrylate(PEGMA) was synthesized by ATRP with macroinitiator which was synthesized from the monodispersed polystyrene(Mn=12000). The molecular weight of obtained PS-b-PEGMA was 22,000.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.337-337
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• 2006

The synthesis of an octafunctional resorcinarene based initiator for nitroxide mediated polymerization and its ability to yield random star copolymers of styrene and methyl methacrylate is studied. The effect of the initiator conformations towards its activity and the conditions that permit the formation of well-defined star block copolymers is also investigated in detail. The characterization of the initiator and the polymers were carried out by various spectro-analytical techniques. Well-defined random copolymers were obtained with controlled molecular weight and low PDI depending on the monomer feed.

• Bulletin of the Korean Chemical Society
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• v.31 no.3
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• pp.570-576
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• 2010

A variety of ynamides undergo highly regio- and stereoselective radical addition of arenethiols with the aid of triethylborane as a radical initiator. The products, N-[(Z)-2-arylsulfanyl-1-alkenyl]amides, can be reduced with triethylsilane in trifluoroacetic acid to yield N-[2-(arylsulfanyl)alkyl]amides.

• Polymer(Korea)
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• v.31 no.6
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• pp.550-554
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• 2007

Atom transfer radical polymerization (ATRP) has been widely used in bioconjugation as it is an efficient and facile method to prepare polymers with pre-designed structures. Quite often, bioconjugation with proteins employs primary amines in proteins as a functional group to attach an initiator. When 2-bromoisobutryl bromide, the most widely used precursor for ATRP initiator, is used, ${\alpha}-halo$ amide initiating groups are formed in the proteins, which are known to exhibit slow initiation behavior in the ATRP process. Here we studied the ATRP of [poly(ethylene glycol)methyl ether] methacrylate (PEGMA) using amide-based initiator. PEGMA differs for both the nature and size of the polymer side branches and shows good solubility in water and a property that made it an ideal candidate for biomaterials. While normal ATRP produced ill-defined p(PEGMA) with amide based initiators, the halogen exchange method and the external additional of deactivator effectively improved the control of ATRP of PEGMA.

• Journal of the Korean Graphic Arts Communication Society
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• v.11 no.1
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• pp.17-29
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• 1993

As inverstigating the influence of monomers and photoinitiator in the polymerization rate of photopolymerization by using IR spectroscopy, photopolymerizations initiated by ultraviolet radiation are characterized by the presence of an autoacceleration in the polymerization rate as the reaction proceeds. The conversion for the end of the autoacceleration varies considerably depending on the monomer and reaction condition which determines coil size and viscosity. In UV curable systems, the autoacceleration begins at only a few percent conversion and continues to 40% in HEA solution and 60% conversion in EHA solution. The polymerization ate in HEA solution increased as follow; DMHA > HCPK > DMPA and could be explained by the interaction between the initiating radical and HEA monomer and the size of the photodissociated radical of initiator. But the tendency of autoacceleration in EHA solution is almost independent on initiator.