Synthesis and Characterization of Macrophotoinitiators of Poly(<i>ε</i>-caprolactone) and Their Use in Block Copolymerization

Degirmenci, Mustafa; Hızal, Gürkan; Yaǧcı, Yusuf

doi:10.1021/ma020668t

Cited by 113 publications

(68 citation statements)

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“…The detailed polymerization conditions and characterization processes were given in previous article. 8 …”

Section: Preparation Of End-chain and Mid-chain Functional Macrophotomentioning

confidence: 99%

“…7 To further enhance the ER properties of ER system we prepared a new series of poly("-caprolactone), and reported the synthesis, characterization and ionomer preparation in an our earlier article. 8 For this ER active ionomer suspensions, the high dielectric constant (933) and conductivity ratios (3:88 Â 10 À8 Sm À1 ) between particles and SO have been considered to be responsible for the strong ER effect ( ¼ 7:4 kPa).…”

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End-chain and Mid-chain Functional Macrophotoinitiators of Poly(ε-caprolactone) and Their Molar Mass Effects on Strong Electrorheological Response

Yılmaz

Degirmenci

Yilmaz

et al. 2006

Polym J

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ABSTRACT:Electrorheological (ER) fluids are suspensions composed of ionomer solid particles dispersed in insulating liquids, which show abrupt changes of rheological properties under the stimulation of an external electric field. In this study, electrical and ER properties of end-chain and mid-chain functional macrophotoinitiators of poly-("-caprolactone) were investigated. For this purpose 4 different samples of poly("-caprolactone) were synthesized with different molar masses. They were then ground milled for a few hours to obtain micron size. The particle sizes of the poly("-caprolactone)s were determined by dynamic light scattering. Suspensions of poly("-caprolactone)s were prepared in silicone oil (SO), at a series of concentrations (c ¼ 5{20%, m/m). The gravitational stability of suspensions against sedimentation was determined at constant temperature (T ¼ 25 C). Flow times of the suspensions were measured under no electric field (E ¼ 0 kV/mm), and under an external applied electric field (E 6 ¼ 0 kV/mm) strengths and a strong ER activities were observed for all the poly("-caprolactone)s/SO suspensions. Further, the effects of suspension concentration, molar mass of the poly("-caprolactone)s, shear rate, electric field strength, frequency, promoter and temperature onto ER activities of suspensions were investigated. [doi:10.1295/polymj.PJ2006048] KEY WORDS Electrorheological Fluids / Ring-Opening Polymerization (ROP) / Poly("-caprolactone) / Molar Mass / Shear Stress / Electrorheological (ER) fluids display remarkable rheological behavior, being able to convert rapidly and repeatedly from a fluid to a solid-like when an external electric field (E) is applied or removed. The wide potential of ER fluids in industrial applications have been attracted much attention, and a great deal of research activities has been carried out in this area.1,2 However, as have been usually recognized, the luck of ER fluids with strong ER effect has become the bottleneck of the development of ER technology, which includes materials design, preparation, and characterization, application establishment and controlling.3 Electrorheological fluids have attracted much industrial attention because of their possible use in devices such as valves, dampers, clutches, brakes and robotic actuators. 4,5 Industrially desired shear stress of ER fluids is usually reported to be not less than 5 kPa under low shear rates. 6 We have recently reported the preparation of ER active suspensions composed of poly(Li-2-hydroxyethyl methacrylate)/SO system, which shown a good ER response with a ¼ 13:75 kPa shear stress.7 To further enhance the ER properties of ER system we prepared a new series of poly("-caprolactone), and reported the synthesis, characterization and ionomer preparation in an our earlier article.8 For this ER active ionomer suspensions, the high dielectric constant (933) and conductivity ratios (3:88 Â 10 À8 Sm À1 ) between particles and SO have been considered to be responsible for the strong ER effect ( ¼ 7:4 kPa).However, to prepare E...

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“…The detailed polymerization conditions and characterization processes were given in previous article. 8 …”

Section: Preparation Of End-chain and Mid-chain Functional Macrophotomentioning

confidence: 99%

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confidence: 99%

End-chain and Mid-chain Functional Macrophotoinitiators of Poly(ε-caprolactone) and Their Molar Mass Effects on Strong Electrorheological Response

Yılmaz

Degirmenci

Yilmaz

et al. 2006

Polym J

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“…This methodology affords possibility to incorporate functional groups into polyesters provided that in addition to the hydroxyl groups, the initiator contains desired functionality. Previously, we have prepared thermal- [21][22][23][24][25][26][27], photo- [28,29], and electro-functional [30] polymers of biocompatible polymers by taking advantage of the functional initiator approach [31].…”

Section: Introductionmentioning

confidence: 99%

Synthesis, characterization, and hydrolytic degradation of graft copolymers of polystyrene and aliphatic polyesters

Küküt

Karal-Yılmaz

Yaǧcı

2012

Designed Monomers and Polymers

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In the present study, a new class of biodegradable graft copolymers of polystyrene (PS) with aliphatic polyester (APE) side chains were synthesized through combination of nitroxide-mediated free radical polymerization (NMRP) and ringopening polymerization (ROP) with copper (I)-catalyzed 'click' chemistry. First, the click component, azido-functional PS (PS-N 3 ) was prepared by copolymerization of styrene and chloromethyl styrene by NMRP followed by the conversion of chlorine groups of the resulting copolymer to azido groups by using NaN 3 in N,N-dimethylformamide. Propargyl functional APEs were prepared independently by ROP of lactic acid and glycolic acid using tin octoate in the presence of propargyl alcohol at 130°C. Finally, PS-N 3 was coupled with the resulting polymers by click chemistry to yield graft copolymers (PS-g-poly (L-lactic-co-glycolic acid) [PLLA] and PS-g-PLLGA, respectively). The intermediates and final graft copolymers were characterized by proton nuclear magnetic resonance ( 1 H NMR) and Fourier transform infrared spectral and gel permeation chromatography analyses. The hydrolytic degradation behavior of the obtained graft copolymers in phosphate buffer saline solution were investigated by the weight loss and molecular weight measurements. It is shown that both copolymers undergo slow hydrolytic degradation, PS-g-PGLLA being relatively faster due to the presence of hydrophilic glycolic acid groups in the structure.

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“…For instance, photoinitiated polymerization methods might accommodate room temperature or below synthesis conditions, which is deficient in synthesis methods employing thermal energy such as thermal curing and free-radical polymer synthesis with thermally degradable initiators [8,9]. In the literature, benzoin, 2-hydroxy-2-methyl-1-phenyl propan-1-one (Darocure 1173), 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl propan-1-one (Irgacure 2959) photoinitiators were used in the synthesis of PCL based macrophotoinitiators via stannous octoate catalyzed living ring-opening polymerization (ROP) to induce photopolymerization of methyl methacrylate (MMA) resulting in block copolymers of ɛ-caprolactone (CL) and MMA [10]. Similarly, mid-chain macrophotoinitiators comprised of poly (D,L-lactide) homopolymer and tetrablock poly(D,Llactide)-poly(ε-caprolactone) copolymers were synthesized via ROP and they were utilized in further installation of MMA units via light induced polymerization [11].…”

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confidence: 99%

Photopolymerization of acrylates by enzymatically synthesized PCL based macrophotoinitiator

Kaya¹,

Önen²,

Güvenilir³

2017

Express Polym. Lett.

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Synthesis and Characterization of Macrophotoinitiators of Poly(ε-caprolactone) and Their Use in Block Copolymerization

Cited by 113 publications

References 24 publications

End-chain and Mid-chain Functional Macrophotoinitiators of Poly(ε-caprolactone) and Their Molar Mass Effects on Strong Electrorheological Response

End-chain and Mid-chain Functional Macrophotoinitiators of Poly(ε-caprolactone) and Their Molar Mass Effects on Strong Electrorheological Response

Synthesis, characterization, and hydrolytic degradation of graft copolymers of polystyrene and aliphatic polyesters

Photopolymerization of acrylates by enzymatically synthesized PCL based macrophotoinitiator

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