• 폴리머
• /
• 제32권4호
• /
• pp.366-371
• /
• 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.

• Elastomers and Composites
• /
• 제23권4호
• /
• pp.289-298
• /
• 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.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1991년도 추계학술대회 논문집 학회본부
• /
• pp.304-306
• /
• 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.

• 한국응용과학기술학회지
• /
• 제19권1호
• /
• pp.33-42
• /
• 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.

• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 1993년도 ACT 93
• /
• pp.776-780
• /
• 1993

• 한국안전학회지
• /
• 제20권3호
• /
• pp.84-90
• /
• 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.

• Elastomers and Composites
• /
• 제47권4호
• /
• pp.329-335
• /
• 2012

지르코늄계 메탈로센 촉매/Borate계 공촉매 시스템을 이용하여 poly(ethylene-ter-high ${\alpha}$-olefin-ter-p-methylstyrene)를 합성하였으며 이 때 사용한 high ${\alpha}$-olefin인 1-hexene, 1-octene, 1-decene, 1-dodecene의 사슬길이 변화가 삼원공중합체에 미치는 여러 가지 영향을 분석하였다. $^{13}C$ NMR과 $^1H$ NMR을 이용하여 삼원공중합체의 구조 및 조성을 확인하였고 high ${\alpha}$-olefin 사슬길이가 촉매활성도, 수율, 분자량 및 분자량분포도 등에 미치는 영향을 살펴보았다. 또한, 사슬 길이 변화에 따른 삼원공중합체의 morphology 변화, 결정화도 변화 및 열적 거동을 비교하였다.

• 공업화학
• /
• 제9권5호
• /
• pp.704-709
• /
• 1998

${\alpha}$-Methyl styrene과 maleic anhydride를 공단량체로 사용하여 유리전이온도가 높고 내열성이 우수한 poly (${\alpha}$-methylstyrene-co-maleic anhydride) (MSMA) 기재 고분자 (substrate polymer)를 합성하고 여기에 니트로기를 가진 발색단을 고분자반응을 이용하여 도입하는 반응 및 생성된 비선형 광학 고분자의 전기 광학 특성에 대해 조사하였다. MSMA 기재 고분자에 hydroxyl기를 가지는 azo계 발색단 (chromophore) 2-[4-(4-nitrophenylazo)-N-ethylphenylamino]ethanol (DR1)을 고분자 반응 (polymer reaction)으로 maleic anhydride에 ester 결합으로 도입할 때 4-dimethylaminopyridine (DMAP) 촉매만을 쓴 것 (MSMA-D)보다 DMAP와 3-dicyclohexyl carbodiimid (DCC)를 동시에 사용한 경우 (MSMA-DC)가 DR1 발색단의 도입율이 높게 나타났다. 비선형 광학 고분자 (MSMA-DC)의 전기광학계수 ($r_{33}$)는 파장이 632.8 nm인 광원에서 18 pm/V의 값을 나타냈으며 열적 안정성도 유리전이 온도 ($T_g$)가 $175^{\circ}C$ 이상으로 우수하게 나타났다.

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 1992년도 추계학술발표강연 및 논문개요집
• /
• pp.121-121
• /
• 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.

• 한국전기전자재료학회논문지
• /
• 제25권7호
• /
• pp.531-536
• /
• 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.