• Polymer Science and Technology
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• v.9 no.3
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• pp.193-199
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• 1998

• Proceedings of the Korean Fiber Society Conference
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• 2002.04a
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• pp.199-202
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• 2002

The synthesis of materials with controlled composition and architectures continues to be a focus of considerable current research. Dendritic multiarm polymers such as dendrimer, hyperbranched polymer, and star polymers are three dimensional macromolecules, in which a large number of linear arms of similar molecular weight and narrow molecular weight distribution emanate from a central core. (omitted)

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.146-147
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• 2006

Polyamides have been widely used in the various industrial fields on account of their excellent properties. Especially the largest market with more than 40% of the total demand is in automobiles and transportation equipment. In this lecture, we would like to introduce several new functional materials (new polyamide elastomer UBESTA XPA, UBESTA gas pipe system and new polyamide terpolymer TERPALEX) based on polyamides developed by UBE. Here UBESTA is the trademark for UBE's polyamide12.

• Bulletin of the Korean Chemical Society
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• v.30 no.6
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• pp.1243-1244
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• 2009

• Elastomers and Composites
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• v.47 no.2
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• pp.162-167
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• 2012

Surface modification of macromolecules renders a progressive and favorable method to enhance the properties of polymeric materials and improves conductivity, wettability, stability, adhesion, antibacterial properties, etc. of polymeric surfaces without deterioration of the polymer bulk properties. Polyolefins such as polyethylene and polypropylene were grafted with maleic anhydride(MAH) as a functional monomer in solution. Evidence for grafting was shown with FTIR measurement. The grafting ratio was determined from chemical titration. The higher MAH loading, the lower contact angle(${\theta}$) was obtained. With the increasing content of MAH, melting temperature($T_m$) of maleic anhydride grafted polymer decreased while decomposition temperature($T_d$) of maleic anhydride grafted polymer increased.

• Macromolecular Research
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• v.12 no.1
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• pp.53-62
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• 2004

We have prepared polymer composites of low-density polyethylene (LDPE) and ionomers (Surlyn 8940) containing polar segments and metal ions by melt blending with carbon black (CB) as a conductive filler. The resistivity and positive temperature coefficient (PTC) of the ionomer/LDPE/CB composites were investigated with respect to the CB content. The ionomer content has an effect on the resistivity and percolation threshold of the polymer composites; the percolation curve exhibits a plateau at low CB content. The PTC intensity of the crosslinked ionomer/LDPE/CB composite decreased slightly at low ionomer content, and increased significantly above a critical concentration of the ionomer. Irradiation-induced crosslinking could increase the PTC intensity and decrease the NTC effect of the polymer composites. The minimum switching current (Ι$\sub$trip/) of the polymer composites decreased with temperature; the ratio of Ι$\sub$trip/ for the ionomer/LDPE/CB composite decreased to a greater extent than that of the LDPE/CB composite. The average temperature coefficient of resistance (${\alpha}$$\sub$T/) for the polymer composites increased in the low-temperature region.

• Journal of the Korean institute of surface engineering
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• v.52 no.2
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• pp.84-89
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• 2019

We fabricated durable anti-reflective(AR) layer with silica globular coating on polymer by two steps. Firstly, nano-protrusions of polymer were formed by plasma etching known as R.I.E(reactive ion etching) process. Secondly, silica globular coating was deposited on polymer nano-protrusions for mechanically protective and optically enhancing AR layers by RF magnetron sputter. And then durable antireflective polymers were synthesized adjusting plasma power and time, working pressures of RIE and RF sputtering processes. Consequently, we acquired the average transmission (94.10%) in the visible spectral range 400-800 nm and the durability of AR layer was verified to sustain its transmission until 5,000 numbers by rubber test at a load of 500 gf.

• Journal of the Korean Wood Science and Technology
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• v.32 no.6
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• pp.67-73
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• 2004

The influence of liquefied wood (LW) on the mechanical and thermal properties of liquefied wood-polymer composites (LWPC) was investigated in this study. The thermal behaviors of LWPC were characterized by means of thermogravimetric (TGA) and differential scanning calorimetric (DSC) analyses. LW showed significant effects on the mechanical strength properties. The increase of flexural MOE and Young's modulus was related to the increase of stiffness of LWPC. The effect of LW was also significant on the flexural and tensile MOR. The impact strength decreased with the increase of LW application level. With the increased stress concentration by the poor bonding between LW and polymer, the impact strength of LWPC decreased, compared with that of high-density polyethylene (HDPE). The thermal stability of LWPC decreased with the increase of LW content up to 40%. The melting temperature of HDPE decreased with the increase of LW loading level. Enthalpy of HDPE also decreased with the addition of LW. This study proves the thermal stability necessary for the consolidation of composition materials.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.200-200
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• 2006

Several polynorbornene or poly(norbornene-7-oxide) based functional block copolymers were synthesized by ring opening metathesis polymerization (ROMP) with good molecular weight and polydispersity control. Some representative functional groups in these polymers are a nitrobenzoyl group or ferrocene. These polymers were subjected to various chemical modification reactions to give other block copolymers that contain novel functionality such as amine, diazonium salt, and diazo groups. The resulting polymers were characterized by various techniques such as GPC, NMR, UV-VIS, AFM, and cyclovotammography (CV).

• Bulletin of the Korean Chemical Society
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• v.29 no.9
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• pp.1699-1704
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• 2008