• Polymer(Korea)
• /
• v.33 no.5
• /
• pp.490-495
• /
• 2009

The reactive compatibilization of amorphous poly-${\alpha}$-olefins (APAO)/amorphous polyamide (aPA) blends was carried out using two kinds of reactive compatibilizers such as maleated polypropylene and ethylene-glycidyl methacrylate-methyl acrylate copolymer. The grafting reaction rates between aPA and the compatibilizers were examined using FT-IR, SEM and rheometer. The effect of the reactive compatibilization on the mechanical property of the blends was investigated with a universal testing machine. The adhesion strength of the blends including a hydrocarbon tackifier resin, C9 was also measured.

• Proceedings of the Polymer Society of Korea Conference
• /
• 2006.10a
• /
• pp.371-372
• /
• 2006

Poly(${\varepsilon}-caprolactone$) (PCL) is a highly crystalline polymer that is miscible with several amorphous polymers including chlorinated polyether, poly(vinylchloride), poly(hydroxyether) and Bisphenol A polycarbonate. The crystallization behavior of miscible blend of amorphous/crystalline polymers has widely been studied. Generally a depression of the crystallization ability has been found with addition of amorphous component because of the reduction of chain mobility, the change of free energy of nucleation as a result of a specific interaction, and so on [1]. In this work, for the first time, the blend of PCL and copolymer of polyurethane containing polycaprolactone as a soft segment is considered. The structural similarity of TPU soft segment with PCL affects on formation of the miscible component and crystallization behavior of PCL in the blend. This has been studied using differential scanning calorimetry (DSC) and Wide-angle X-ray Scattering (WAXS).

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.303.1-303.1
• /
• 2016

Polymer-like amorphous carbon films were deposited on polyethylene naphthalate (PEN) substrate by plasma-enhanced chemical vapor deposition (PECVD) and their water vapor transmission rates (WVTR) were tested. propane was used as precursors. To make a polymer-like amorphous carbon film the deposition rate, surface roughness, light transmittance, and WVTR of the films were characterized as a function of the precursor feed ratio and plasma power. The water vapor transmission rates of bare PEN film and single layer PAC on PEN substrate were 6.95 g/m2/day and 0.3 g/m2/day, respectively. The superior property the water vapor permeability of thin layers of PAC was attributed to uniform coverage and good adhesion between PAC film and PEN substrate.

• Polymer Science and Technology
• /
• v.8 no.1
• /
• pp.67-74
• /
• 1997

• Polymer Science and Technology
• /
• v.8 no.2
• /
• pp.211-218
• /
• 1997

• Macromolecular Research
• /
• v.15 no.7
• /
• pp.662-670
• /
• 2007

The crystallization behavior and fine structure of poly(ethylene terephthalate) (PET)/A-zeolite nanocomposites were assessed via differential scanning calorimetry (DSC) and time-resolved small-angle X-ray scattering (TR-SAXS). The Avrami exponent increased from 3.5 to approximately 4.5 with increasing A-zeolite contents, thereby indicating a change in crystal growth formation. The rate constant, k, evidenced an increasing trend with increases in A-zeolite contents. The SAXS data revealed morphological changes occurring during isothermal crystallization. As the zeolite content increased, the long period and amorphous region size also increased. It has been suggested that, since PET molecules passed through the zeolite pores, some of them are rejected into the amorphous region, thereby resulting in increased amorphous region size and increased long period, respectively. In addition, as PET chains piercing into A-zeolite pores cannot precipitate perfect crystal folding, imperfect crystals begin to melt at an earlier temperature, as was revealed by the SAXS profiles obtained during heating. However, the spherulite size was reduced with increasing nanofiller content, because impingement between adjacent spherulites in the nanocomposite occurs earlier than that of homo PET, due to the increase in nucleating sites.

• Macromolecular Research
• /
• v.15 no.2
• /
• pp.185-190
• /
• 2007

Poly(norbornene dimethyl dicarboxylate)s, (PNDMD)s, were prepared by addition polymerization with palladium(II) catalyst from pure exo-monomers, and their structure and properties were compared with those of poly(norbornene dicarboxylic acid dialkyl ester)s, (PNDADA)s. Both polymer series exhibited good solubility in general organic solvents and excellent thermal stability up to $330^{\circ}C$. Wide-angle X-ray scattering (WAXS) study indicated the presence of nano-scale layer-like order in amorphous PNDADAs, while PNDMDs showed random amorphous structure. The glass transition temperatures and dielectric constants of solid polymers were found to decrease as the alkyl side-chain length increases for both polymer series. However, PNDMDs showed lower glass transition temperatures and higher dielectric constants, as compared with those of PNDADAs containing the same alkyl substituents. This difference, caused by the higher side-group mobility of PNDMDs, may be closely related to the nano-scale order in amorphous PNDADAs and its absence in PNDMDs.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.1455-1458
• /
• 2008

Amorphous silicon (a-Si:H) thin-film transistors (TFTs) are fabricated on flexible organic polymer foil substrates. As-fabricated performance, electrical bias-stability at elevated temperatures, electrical response under mechanical flexing, and prolonged mechanical stability of the TFTs are studied. TFTs made on plastic at ultra low process temperatures of $150^{\circ}C$ show initial electrical performance like TFTs made on glass but large gate-bias stress instability. An abnormal saturation of the instability against operation temperature is observed.

• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.9 s.174
• /
• pp.173-178
• /
• 2005

Recently plastic parts are molded for the purpose of mass production in multi-cavity system. Therefore, designer is usually designing mold that has geometrically balanced runner lay-out for filling balance at each cavity. Although, mold is manufactured with geometrically balanced runner lay-out, there are actually filling imbalances in the cavities. These filling imbalances phenomenon are caused by complicated interaction between melt and mold. In this study, based on previous studies for filling imbalances in cold-runner mold, filling imbalances in hot-runner mold were investigated by CAE and injection molding experiments. ABS and PMMA as amorphous polymer, PA as crystalline polymer were used to compare the filling imbalances. There were different results of CAE and experiment. The filling imbalances decreased as injection rate increased without regard to kind of resins and were lower than the one of cold-runner.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.598-601
• /
• 2005

Plastic parts are molded for the purpose of mass production in multi-cavity system. Therefore, designer is usually designing molds that has geometrically balanced runner lay-out for filling balance at each cavities. Although, mold is manufactured with geometrically balanced runner lay-out, there are actually filling imbalances in cavities. These filling imbalances phenomenon are caused by complicated interaction between melt and mold. In this study, based on previous studies for filling imbalances in cold-runner mold, filling imbalances in hot-runner mold were investigated by CAE and injection molding experiments. ABS, PMMA as amorphous polymer and PA, PP as crystalline polymer were used to compare the filling imbalances. The filling imbalances decreased as injection rate increased without regard to kind of resins and were lower than the one of cold-runner.