• Bulletin of the Korean Chemical Society
• /
• v.32 no.4
• /
• pp.1303-1309
• /
• 2011

Melt copolymerization reactions of bis(diethylamino)tetramethyldisiloxane with several aryldiols were carried out to afford poly(carbotetramethyldisiloxane)s containing fluorescent aromatic chromophore groups in the polymer main chain: poly{oxy(4,4'-biphenylene)oxytetramethyldisiloxane}, poly{oxy(1,4-phenylene)oxytetramethyldisiloxane}, poly[oxy{(4,4'-isopropylidene)diphenylene}oxytetramethyldisiloxane], poly[oxy{(4,4'-hexafluoroisopropylidene)diphenylene}oxytetramethyldisiloxane], poly{oxy(2,6-naphthalene)oxytetramethyldisiloxane}, poly[oxy{4,4'-(9-fluorenylidene)diphenylene}oxytetramethyldisiloxane], poly{oxy(fluorene-9,9-dimethylene)oxytetramethyldisiloxane}, and poly[oxy{4,4'-(9-fluorenylidene)bis(2-phenoxyethylene)}oxytetramethyldisiloxane]. These materials are soluble in common organic solvents such as $CHCl_3$ and THF. The FTIR spectra of all the polymers exhibit the characteristic Si-O-C stretching frequencies at 1021-1082 $cm^{-1}$. In the THF solution, the polymeric materials show strong maximum absorption peaks at 215-311 nm, with strong maximum excitation peaks at 250-310 nm, and strong maximum fluorescence emission bands at 310-360 nm. TGA thermograms indicate that most of the polymers are stable up to $200^{\circ}C$ with a weight loss of less than 10% in nitrogen.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.42 no.2 s.332
• /
• pp.15-22
• /
• 2005

Using the existing analog circuits, required resistor matching and Poly-Si TFT characteristics are investigated for the implementation of analog circuits to be integrated on System-on-Glass. Matching requirements on resistor values, threshold voltage and mobility of poly-Si TFT are derived as a function of the resolution of display system. Also, the effective mobility of poly-Si TFT required for the realization of source driver is analyzed for various panel sizes.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.40 no.1
• /
• pp.91-98
• /
• 1991

Electrical conductivity of poly (3-alkylthiophene) derivatives with substituted long alkyl chain such as poly (3-butylthiophene), poly (3-hexylthiophene), poly (3-octylthiophene), poly (3-decylthiophene), poly (3-dodecylthiophene), and poly (3-docosylthiophene) increases with increasing temperature. However, after attaining a maxiumum value, it decreases with further temperature increase. Hysteresis is also observed in the temperature dependence of conductivity and absorption spectra. The absorption spectra also changes rapidly at the phase transition. These phenomena are discussed in terms of the increase of the energy band gap in the liquid states due to the decrease of co-planarity of thiophene rings accompanied by remarkable conformation changes.

• Textile Coloration and Finishing
• /
• v.8 no.2
• /
• pp.49-55
• /
• 1996

Poly(4, 4'-diphenyl ether pyromellitamic acid) was prepared from pyromellitic anhydride with 4, 4'-diamino diphenyl ether by means of low-temperature solution polymeriztion. The reation was exothermic and very fast when carried out at room temperature. The synthesized poly(4, 4'-diphenyl ether pyromellitamic acid) was converted to poly(4, 4'-diphenyl ether pyromellitimide) by thermal dehydrocyclization. FTIR analysis was widely used as a means of determining the course of imidization from intensity of characteristic bands of the imide ring at $1790cm^{-1}$ and $1490cm^{-1}$. The density of poly(4, 4'-diphenyl ether pyromellitimide) was higher than poly(4, 4'-diphenyl ether pyromellitamic acid) indicating the greater crystallinity, perhaps because of the reduction of molar volume of polymers

• Journal of Pharmaceutical Investigation
• /
• v.22 no.3
• /
• pp.237-240
• /
• 1992

A series of biodegradable block copolymers consisting of $poly({\gamma}-benzyl\;L-glutamate)$ (PBLG) and poly(ethylene oxide) (PEO)-lactoselactone were prepared by polymerization of PEO-lactoselactone and ${\gamma}-benzyl$ L-glutamate-N-carboxyanhydride and characterized by IR and NMR. From circular dichroism measurements, it was found that the polymers exist in the ${\alpha}-helical$ conformation. Block copolymer microspheres were prepared by solvent-extraction-precipitation method for their primary evaluation for medical and biological applications.

• Electrical & Electronic Materials
• /
• v.10 no.8
• /
• pp.794-799
• /
• 1997

Poly-Si films have been prepared by solid phase crystallization of LPCVD(low-pressure CVD) amorphous silicon. The crystallinity of poly-Si films has been derived from UV reflectance spectrum and lies in the range between 70% and 80% . From XRD measurement the peak at 28.2$^{\circ}$from (111) plane is dominantly detected in the SPC poly-Si films, The average grain size of poly-Si film is determined by the image of SEM and varies from 4000 $\AA$ to 8000$\AA$. The electrical conductivity of as-deposited amorphous silicon film is about 2.5$\times$10$^{-7}$ ($\Omega$.cm)$^{-1}$ , and 3~4$\times$10$^{-6}$ ($\Omega$.cm)$^{-1}$ of room temperature conductivity is the SPC poly-Si films. The conductivity activation energies are 0.5~0.6 eV or the 500$\AA$-thick poly-Si films.

• Polymer(Korea)
• /
• v.25 no.2
• /
• pp.226-232
• /
• 2001

The properties of poly(ethylene terephthalate) (PET)/maleic anhydride-grafted polypropylene (MAgPP)/poly(styrene-co-maleic anhydride)(PScMA) ternary blend were investigated. The ternary blend was immiscible based on the glass transition temperatures measured by dynamic mechanical analyzer (DMA). The degradation of MAgPP during melt mixing for 30 min at 280$^{\circ}C$ did not affect the properties of the ternary blend. The interaction among the components was confirmed from the rheological properties, which was increased with the PSCMA contents. In terms of the mechanical properties, it was observed to satisfy the mixture rule for a multiple system.

• Journal of applied mathematics & informatics
• /
• v.39 no.1_2
• /
• pp.45-56
• /
• 2021

D.S. Kim et al. [9] considered some identities and relations for Korobov type numbers and polynomials. In this work, we investigate the degenerate Korobov type Changhee polynomials and the (p,q)-poly-Korobov polynomials. We give a generalization of the Korobov type Changhee polynomials and the (p,q) poly-Korobov polynomials. We prove some properties and identities and explicit relations for these polynomials.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.1182-1184
• /
• 2006

A mica has been introduced as a new substrate material for the fabrication of the poly-Si TFTs. A poly-Si film is produced on the mica substrate at $550^{\circ}C$ by the nickel-induced crystallization and the poly-Si TFTs on the mica substrate are successfully fabricated for the first time.

• Honam Mathematical Journal
• /
• v.41 no.4
• /
• pp.781-798
• /
• 2019

This paper is designed to introduce a Hermite-based-poly-Bernoulli numbers and polynomials with q-parameter. By making use of their generating functions, we derive several summation formulae, identities and some properties that is connected with the Stirling numbers of the second kind. Furthermore, we derive symmetric identities for Hermite-based-poly-Bernoulli polynomials with q-parameter by using generating functions.