• Polymer(Korea)
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• v.25 no.6
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• pp.833-839
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• 2001

The crystallization characteristics of metallocene linear low density polyethylene was investigated by small angle light scattering and comparison was made with Ziegler-Natta linear low density polyethylene. The special efforts were made to find out the effects of branching number, length of branching and co-monomer content of m-LLDPE on the crystallization behavior of m-LLDPE. It was found that m-LLDPE has longer induction time to start crystallization from the amorphous state than that of conventional LLDPE with similar branching number, but the rate of crystallization seems not change much in both LLDPEs. Lowering of branching number in m-LLDPE resulted in both increasing of rate of crystallization and reducing induction time to crystallize. In general, the maximum size of spherulites of m-LLDPE is bigger than that of conventional LLDPE.

• Journal of the Korean Applied Science and Technology
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• v.28 no.3
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• pp.306-312
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• 2011

In this study, we are crystallized to the low density polyethylene (LDPE) micro-particles in $n$-dodecanol solution by thermally induced phase separation(TIPS) method. The Low density polyethylene micro-particles is used in a wide variety of polymer coatings and industrial application. The utility of that for a particular application depends on a number of factors such as the particle size and distribution, and chemical composition of the materials. However, there are still needs for new methods of preparation which will provide the structure with unique sizes. The widely used processes for micro-size particles are crystallization method and thermally induced phase separation. TIPS process based on the phase separation mechanism was performed for the LDPE system which undergoes liquid-solid phase separation. Effects of various operating parameters were examined on the structure variation of the particles. Professionality, take-up speed and crystallization rate depended on temperature and concentration of polymer in solution.

• The Korean Journal of Rheology
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• v.10 no.4
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• pp.256-258
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• 1998

An experimental study was done to improve the processability and optical property of linear low density polyethylene(LLDPE) film. By modifying the molecular structure of LLDPE with electron beam we could get the improved processability and optical property of film. By appropriate dosing of electron beam and a small addition of UV-stabilizer it was possible to produce gel-free film with low haze. The proceassability was also improved.

• Journal of the Korean Wood Science and Technology
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• v.32 no.1
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• pp.67-72
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• 2004

Wood/polyethylene panels were manufactured from Populus alba × glandulosa particles and low density polyethylene particles at three mixing rates, 50:50, 60:40, and 70:30. A total of 15 wood/polyethylene panels was made at 145℃ and 5 minutes hot-press time. Wood/polyethylene panels were tested for internal bond, bending, and dimensional stabilities such as thickness swell and water absorption. Panel performance data were analyzed using the SAS programing package. The test results of the wood/polyethylene panels showed that as the polyethylene mixing rates were increased, the panel property values increased. Based on panels' dimensional stabilities, the optimum wood/polyethylene mixing ratio appeared to be 60:40.

• 전기의세계
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• v.29 no.8
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• pp.511-518
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• 1980

The thermostimulated discharge currents of low-density polyethylene electrets were measured versus the principal experimental variables. Several electrode types were used for the charging and discharging procedures. The results led to know the experimental conditions for the heterocharge and homocharge accumulating and decreasing. The electronic structure parameters of polyethylene such as trap level, density of traps, hopping length, mobility, trap time constants were deduced. A method for evaluating the local electric field inside the electret is proposed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.191-194
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• 1998

In this paper, the physical and conductivity properties due to the electron beam irradiation for low density polyethylene using insulating materials of the distribution cable and ultra-high voltage cable are studied. The specimens of the low density polyethylene of thickness 100[$\mu\textrm{m}$] irradiated as each 1 [Mrad], 2[Mrad], 4[Mrad], 8[Mrad], 16[Mrad] and virgin are used in this experiment. In order to measure the conductivity properties, the micro electrometer is used, the range of temperature and app1ying voltage are 20 to 120[$^{\circ}C$], from 100 to 1000[V] respectively So. as a result of the conductivity properties, it is confirmed that the conductivity is increased nearly to 50[$^{\circ}C$], and is not changed until the crystalline melting point from the temperature over 60[$^{\circ}C$] because of the defects of morphology and the formation of many trap centers by means of electron beam irradiation

• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.1
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• pp.17-25
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• 1986

Discussions on this paper are related to the effects of organic materials to treeing phenomena of low density polyethylene. As additives, 11 kinds of organic compounds are selected by considering the respective features such as melting point, boiling point, electron affinity as well as molecular structure, and then the specimens of low density polyethylene are prepared by blending with 10wt% of the selected additives. For the comparison of effectiveness of treeing resistance and interpretation of the mechanism of compounds as treeing retardants, several investigations such as the tree acceleration test, the prestressed test and the measurement of internally occurred partial discharge are carried out. As the results, meta-Cresol is regard as the most effective retardant among those, and it is supposed that this aromatic compound to be comprised of radical having large electron affinity has strong capability to accept energetic electron to prevent or delay the growth of discharge streamer. Furthermore, by activating partial discharge at the wall of tree pit through the function of trapped electron at this material, the gas pressure in the pit is increased up to prevent the growth of streamer.

• Fibers and Polymers
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• v.5 no.4
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• pp.270-274
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• 2004

Blends of poly(l-lactide) (PLA) and low density polyethylene (LDPE) were prepared by melt mixing in order to improve the brittleness of PLA. A reactive compatibilizer with glycidyl methacrylate (GMA), PE-GMA, was required as a compatibilizer due to the immiscibility between PLA and LDPE. It contributes to reduce the domain size of dispersed phase and enhance the tensile properties of PLA/LDPE blends, especially for PLA matrix blends. A reaction product between PLA and PE-GMA, which was formed during melt-mixing and considered to act as a reactive compatibilizer, was characterized using $ ^1H-NMR$ spectroscopy.

• Nuclear Engineering and Technology
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• v.9 no.1
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• pp.7-13
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• 1977

This paper attempted to investigate the temperature characteristics and electrical conduction when low density polyethylene is irradiated. It was found that the log $\rho$ versus 1/T in irradiated polyethylene specimen resulted in different characteristics when it was heated upto above the melting point from when it was heated at the beginning stage. It was also found that the relation between the temperature and volume resistivity represented jumping phenomenon and that crystallization by thermal change was closely related to the fusion of crystalline region.

• Journal of Environmental Science International
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• v.22 no.10
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• pp.1287-1294
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• 2013

In this study, thermoplastic starch (TPS), cross-linked starch (CS), and cross-linked starch modified with glycerol (CTPS) were prepared, and the mechanical properties of the compatibilized low-density polyethylene (LDPE) blends (LDPE/TPS, LDPE/CS, and LDPE/CTPS) were investigated and compared with those of uncompatibilized LDPE/TPS, LDPE/CS, and LDPE/CTPS blends. Maleic-anhydride-grafted polyethylene was used as the compatibilizer. The enhanced tensile strength and elongation at break for the compatibilized LDPE/modified starch blends are a result of the improved compatibility between LDPE and the modified starch, which was confirmed by torque measurements and scanning electron microscopy.