• Title/Summary/Keyword: poly($\alpha$-methylstyrene)

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Kinetic Studies on Homopolymerization of $\alpha$-Methylstyrene and Sequential Block Copolymerization of Isobutylene with $\alpha$-Methylstyrene by Living/Controlled Cationic Polymerization (리빙/조절 양이온중합에 의한 알파메틸스티렌 호모중합 및 이소부틸렌과의 블록공중합에 대한 반응속도론 연구)

  • Wu, Yibo;Guo, Wenli;Li, Shuxin;Gong, Huiqing
    • Polymer(Korea)
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    • v.32 no.4
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    • pp.366-371
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    • 2008
  • The controlled/living cationic polymerization of $\alpha$-methylstyrene (${\alpha}MeSt$) and sequential block copolymerization of isobutylene (IB) with ${\alpha}MeSt$ were achieved using 2-chloro-2,4,4-trimethylpentane (TMPCl)/titanium tetrachloride ($TiCl_4$)/titanium isopropoxide ($Ti(OiPr)_4$)/2,6-ditert-butylpyridine (DtBP) initiating system in $CH_3Cl$/hexane(50/50 v/v) solvent mixture at $-80^{\circ}C$. The polymerization rate decreased with increasing $[Ti(OiPr)_4]/[TiCl_4]$ ratio in the homopolymerization of ${\alpha}MeSt$. The effects of $[Ti(OiPr)_4]/[TiCl_4]$ ratios and $PIB^+$ molecular weight on the polymerization rate and blocking efficiency were also investigated. Well-defined poly(isobutylene-b-$\alpha$-methylstyrene)s were demonstrated by $^1H$-NMR and triple detection SEC; refractive index (RI), multiangle laser light scattering (MALLS) and ultraviolet (UV) detectors. Blocking efficiencies for the poly(isobutylene-b-$\alpha$-methylstyrene)s of almost 100% were obtained when ${\alpha}MeSt$ was induced by PIB's of $M_n\;{\geq}\;41000$ at $[Ti(OiPr)_4]/[TiCl_4]=1$. Differential scanning calorimetry (DSC) of the block copolymers showed two glass transition temperatures, thereby demonstrating microphase separation.

Study on The Thermal Properties of Poly(methyl methacrylate) and Poly($\alpha$-methylstyrene-co-acrylonitrile) Mix tures (Poly(methyl methacrylate)와 Poly($\alpha$-methylstyrene-co-acrylonitrile) 혼합물의 열적특성에 관한 연구)

  • Moon, Deog-Ju;Kim, Byung-Chul;Kim, Dong-Keun;Seul, Soo-Duk;Sohn, Jin-Eon
    • Elastomers and Composites
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    • v.23 no.4
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    • pp.289-298
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    • 1988
  • The thermal degradation of poly(methyl methacrylate)(PMMA) and poly($\alpha$-methylstyrene-co-acrylonitrile)(SAN) mixtures were carried out using the thermogravimetry(TG) and differential scanning calorimetry(DSC) in the stream of nitrogen and air with 50 ml/min at the various heating rate from 4 to $20^{\circ}C/min$ and temperature from 20 to $500^{\circ}C$. The value of activation energies of thermal degradation determined by TG and DSC in the various PMMA/SAN mixtures were 34-54 kcal/mol in the stream of nitrogen. The value of activation energy of SAN 60% mixture were appeared high in comparison with addition rule. PMMA/SAN mixtures by the analysis of infrared spectrophotometer were decomposed by main chain scission in the stream of nitrogen.

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Poly-$\alpha$-methylstyrene Films by Plasma Polymerization(I) (플라즈마 중합된 Poly-$\alpha$-methylstyrene 박막(I))

  • Park, Sang-Hyun;Lee, Chwi-Cwung;Han, Sang-Ok;Lim, Youg-Hoon;Lee, Deok-Chool
    • Proceedings of the KIEE Conference
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    • 1991.11a
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    • pp.304-306
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    • 1991
  • A new gas-flow type reactor for plasma polymerization was developed to symthesize functional polymer, which enhances the reaction of radicals activated in discharge. $\alpha$-Methylstyrene was used for the polymerization, which are known as starting monomers for the polymer with degradating characteristics. The molecular structure and molecular weight distribution of the polymers were studied.

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The Kinetics of Radical Copolyerization of ${\alpha}$-Methylstyrene with Acrylonitrile in a CSTR (연속반응기에서 ${\alpha}$-Methylstyrene과 Acrylonitrile 라디칼 공중합 속도론)

  • Kim, Nam-Seok;Park, Keun-Ho
    • Journal of the Korean Applied Science and Technology
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    • v.19 no.1
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    • pp.33-42
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    • 2002
  • Copolymerization of ${\alpha}$-Methylstyrene(AMS) with Acrylonitrile(AN) was carried out with benzoylperoxide(BPO) as an initiator in toluene at $80^{\circ}C$ in a continuous stirred tank reactor. Reaction volume and residence time were 0.6 liters and 3 hours, respectively. The monomer reactivity ratios, $r_{AMS}$ and $r_{AN}$ determined by both the Kele$T{\"{u}}d\"{o}s$ method and the Fineman-Ross method were $r_{AMS}$=0.16(0.14), $r_{AN}$=0.04(0.06). The cross-termination factor ${\Phi}$ of the copolymer over the entire AMS composition ranged from 0.75 to 0.92. The ${\Phi}$ factors of poly(AMS-co-AN) were increased with increasing AMS content. The simulated conversions and copolymerization rates were compared with the experimental results. It was observed that the average time to reach dynamic steady-state was three times the residence time.

A Study of Thermal Decomposition Characteristics of Poly(${\alpha}$-Methylstyrene-co-Acrylonitrile) (${\alpha}$-SAN 공중합체의 열분해 특성에 관한 연구)

  • Kim, Nam-Seok;Seul, Soo-Duk;Park, Keun-Ho;Lee, Woo-Nae;Kim, Duck-Sool;Lee, Seok-Hee
    • Journal of the Korean Society of Safety
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    • v.20 no.3 s.71
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    • pp.84-90
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    • 2005
  • Thermal decomposition of the copolymer of ${\alpha}$-Methylstyrene(AMS) with Acrylonitrile(AN) was investigated. The copolymer was synthesized in a continuous stirred tank reactor(CSTR) at $80^{\circ}C$ using toluene and benzoyl peroxide(BPO) as solvent and initiator, respectively. The reactor volume was 0.3 liters and residence time was 3 hours. The activation energy of thermal decomposition was in the ranges of $34{\sim}54$ kcal/mol for AMS with AN copolymer. The thermogravimetric trace curves were well agreed with the theoretical calculation.

Effects of the Chain Length of High α-olefins on the Terpolymerization (High α-olefin의 사슬길이가 삼원공중합에 미치는 영향)

  • Kim, Tae-Wan;Lee, Jun Chul;Park, No-Hyung;Kim, Hyun Ki;Cho, Ur-Ryong;Kim, Dong Hyun
    • Elastomers and Composites
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    • v.47 no.4
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    • pp.329-335
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    • 2012
  • In this study, we synthesized poly(ethylene-ter-high ${\alpha}$-olefin-ter-p-methylstyrene) using Zr metallocene catalyst/borate type cocatalyst system. Various effects of the high ${\alpha}$-olefin (1-hexene, 1-octene, 1-decene, and 1-dodecene) were observed. The structure and composition of the terpolymers were characterized using $^{13}C$ NMR and $^1H$ NMR. Catalytic activity, polymer yield, molecular weight and molecular weight distribution were analyzed according to the chain length of high ${\alpha}$-olefin. We determined morphology, crystallinity and thermal properties of the terpolymers.

Synthesis and Properties of Nonlinear Optical Polymer Derived from α-Methyl Styrene/Maleic Anhydride by Polymer Reaction (고분자 반응을 이용한 Maleic anhydride계 비선형 광학 고분자의 합성 및 전기광학 특성)

  • Park, Lee Soon;Keum, Chang Dae;Song, Jae Won;Kim, Kwang Taek;Kim, Gi Heon;Kang, Shin Won
    • Applied Chemistry for Engineering
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    • v.9 no.5
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    • pp.704-709
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    • 1998
  • Non-linear optical polymer based on poly (${\alpha}$-methylstyrene-co-maleic anhydride) (MSMA) substrate polymer was prepared by polymer reaction method and its thermal and electro-optic properties were examined. In the polymer reaction between MSMA substrate polymer and 2-[4-(4-nitrophenylazo)-N-ethylphenylamino]ethanol (DR1) chromophore, the degree of substitution of DR1 into MSMA was higher with the 4-dimethylaminopyridine (DMAP) as catalyst and 3-dicyclohexyl carbodiimide (DCC) as dehydrating agent (sample, MSMA-DC) than the one with just 4-dimethylaminopyridine as catalyst (sample, MSMA-D). The synthesized NLO polymer (MSMA-DC) exhibited electro-optic coefficient of 18 pm/V (632.8 nm) and glass transition temperature ($T_g$) of about $175^{\circ}C$.

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Deformation Behavior in Compatible Polymer Blends (고분자블렌드에서의 변형거동)

  • 전병철
    • Proceedings of the Materials Research Society of Korea Conference
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    • 1992.05a
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    • pp.121-121
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    • 1992
  • Deformation behavior of compatible polymer blends was studied using scanning electron, optical, and transmission electron microscopies. Four different compatible systems were employed and charaterized in this investigation : polystyrene(PS) and polyphenylene oxide(PPO), polystyrene(PS) and polyvinlmethylether(PVME), polystyrene(PS) and poly $\alpha$-methylstyrene(P$\alpha$MS). Individual craze and shear deformation zone microstructures were examined by transmission microscopy (TEM). For TEM observations, specimens deformed in-situ on a TEM grid were utilized. Quantiative analysis of these crazes and shear deformation zones was obtained from the nicrodensitometry of the TEM negatives in the manner developed by Lauterwasser and Kramer. Microdensitometry resulys showed that the fibril extension ratio decreased as the PPO content increased in the PS/PPO blends, and finally, for 100% PPO, only shear deformation zones were observed. For the PS/PVME blends, the ribril extension ratio also decreased as the VME content increased. For the PS/P$\alpha$MS blends, the fibril extension ratio increased as the P$\alpha$MS content increased, For the PPO/P$\alpha$MS blends, the fibril extension ratio increased as the P$\alpha$MS content increased.

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Organic Semiconducting Thin Films Fabricated by Using a Pre-metered Coating Method for Organic Thin Film Transistors (정량 주입(Pre-metered) 코팅 방식을 이용한 유기 트랜지스터 반도체 박막 제작 연구)

  • Cho, Chan-Youn;Jeon, Hong-Goo;Choi, Jin-Sung;Kim, Yun-Ki;Lim, Jong-Sun;Jung, J.;Cho, Song-Yun;Lee, Chang-Jin;Park, Byoung-Choo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.7
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    • pp.531-536
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    • 2012
  • We herein present results of flat and uniform polymer-blended small molecular semiconductor thin films. Which were produced for organic thin film transistors (OTFTs), using a simple pre-metered horizontal dipping process. The organic semiconducting thin films were composed of 6,13-bis(triisopropylsilylethynyl)-pentacene (TIPS-PEN) composite blended with a polymer binder of poly(${\alpha}$-methylstyrene) (PaMS). We show that the pre-metered horizontal-dip-coating(H-dip-coating) process allowed the critical control of the thickness of the blended TIPS-PEN:PaMs thin film. The fabricated OTFTs using the TIPS-PEN:PaMs films exhibited maximum field-effect mobility of $0.22\;cm^2\;V^{-1}\;s^{-1}$. These results demonstrated that H-dip-coated TIPS-PEN:PaMS films show considerable promise for the production of reliable, reproducible, and high-performance OTFTs.