• Applied Chemistry for Engineering
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• v.25 no.6
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• pp.598-601
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• 2014

The effects of process parameters for the formation of polypropylene film such as the polypropylene concentration in the solution, drying temperature for coating film, and variation of nano-silica content on the surface structure and property of polypropylene film have been studied. A super-hydrophobic polypropylene film with a maximum contact angle of $154^{\circ}$ was obtained at the condition of a polypropylene concentration of 30 mg/mL, a drying temperature of $30^{\circ}C$, a drying pressure of 93 mtorr for 90 min. The increase of a drying temperature reduced the contact angle by enhancing the surface smoothness of the film. The increase of nano-silica content in the composite film composed of polypropylene and silica changed the surface shape from microporous to microglobular, which led to increasing the contact angle and showed the super-hydrophobic surface property.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.4
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• pp.409-413
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• 2013

A polypropylene film was ablated using a $CO_2$ laser, Ti-sapphire femtosecond laser, and UV nanosecond laser. For modified atmosphere packaging, polypropylene films were ablated by laser pulse with different pulse energies and measured on an optical microscope. Also, we observed the shelf life of a banana contained within packaging of a breathable zipper bag. As a result, we have demonstrated that the breathable film can efficiently extend the shelf life of respiring foods, particularly fresh fruits and vegetables. The development of breathable film laser microfabrication system will more useful for industrial applications.

• Elastomers and Composites
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• v.56 no.4
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• pp.217-222
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• 2021

In this study, random polypropylene (rPP) was compounded with two of monoglycerides, namely, glyceryl monolaurate (GML) and glyceryl monostearate (GMS), as antifogging agents to improve its antifogging performance. rPP film samples were prepared by a film-casting method using a three-roll casting machine after melt blending through a twin screw extruder. With an increase in the monoglyceride content, the melt flow index for rPP films with GML and GMS increased, and their yield strength decreased. The incorporation of GMS in rPP was proven to be more effective in improving its physical properties than was rPP with GML. When GML and GMS were separately added to the rPP film at contents of more than 1 phr and more than 5 phr, respectively, the film exhibited antifogging performance.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1584-1586
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• 1999

The polypropylene has been known to have higher melting temperature than Polyethylene. and good mechanical properties. This paper introduces the experiment result for tree properties of polypropylene thin film with a crystal structure. According to the experiment. tree properties is appeared boundary section of thin film first of all. Also, Spherulites magnitude of slow cooling is larger than that of rapid cooling.

• Journal of the Korean Society of Safety
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• v.28 no.6
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• pp.17-22
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• 2013

The production of flame-retardant polypropylene powder coating with the addition of flame retardant (PP) controlled rheology (CR) and polypropylene, were discussed comparing the mechanical properties, such as safety and topical coating properties. Mechanical properties measurements showed almost the same as AA-1 where the flame retardant is not added. These results appear to, and because it is excellent in compatibility with polypropylene and flame retardant. Physical properties of the coating film, a test piece flame retardant organic is added, although it shows the physical properties of the coating film was stable, did not show the physical properties satisfactory is the test piece flame retardant of weapons has been added. In the safety of the topic, AA-4, AA-5 the results of thermal analysis but it is excellent, the LOI is excellent in 27.8 vol% 27.0 vol% in AA-4 and AA-2, AA-3, and 27.4 vol%, did not show many obstacles flame AA-5 result UL94.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.247-248
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• 2008

• Textile Coloration and Finishing
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• v.11 no.2
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• pp.27-37
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• 1999

Polypropylene(PP) films were treated with plasma glow discharge to produce peroxy radicals on the surfaces. The peroxy radicals formed on the PP film surfaces were subsequently used for the graft polymerization of acrylic acid and acrylamide in an aqueous solution by heating, respectively. Introduction of acrylic acid and acrylamide on the PP film could be confirmed by the observation of carbonyl and primary amine absorptions based on carboxylic acid and amide, respectively. And introduction of functional group could be confirmed by weight analysis and ESCA. The water contact angle(90$^{\circ}$) of PP film was constant, irrespective of elapsed time, while plasma-treated and functional monomer-grafted PP films were slowly increased with elapsed time, showing the rearrangement of surface polar groups in air condition. The water contact angle$(90^\circ)$ of PP film was decreased by the plasma treatment$(56^\circ)$ and further decreased by the grafting of acrylic acid$(34^\circ)$ and acrylamide$(37^\circ)$, indicating increased hydrophilicity of the modified surfaces. The water contact angle of plasma-treated PP film increased a little as time elapsing. The half-life periods of surface voltage on acrylic acid-(31sec) and acrylamide-grafted PP(42sec) were significantly decreased when compared to those on PP(950sec) and plasma-treated PP film(241sec). In the experiments using acid, basic and disperse dyes, absorbance and $\Delta{E}$ values of functional monomer-grafted PP films were significantly increased than that of oxygen plasma-treated one.

• Transactions on Electrical and Electronic Materials
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• v.12 no.3
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• pp.110-114
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• 2011

Polymeric films of high chemical stability and mechanical strength covered with a thin metallic film have been extensively used in various fields as electric and electronic materials. In this study, we have chosen polypropylene (PP) as the polymer due to its outstanding chemical resistance and good creep resistance. We coated thin nickel film on PP films by the electroless plating process. The surfaces of PP films were pre-treated and modified to increase the adhesion strength of metal layer on PP films, prior to the plating process, by an environment-friendly process with atmospheric plasma generated using dielectric barrier discharges in air. The surface morphologies of the PP films were observed before and after the surface modification process using a scanning electron microscope (SEM). The static contact angles were measured with deionized water droplets. The cross-sectional images of the PP films coated with thin metal film were taken with SEM to see the combined state between metallic and PP films. The adhesion strength of the metallic thin films on the PP films was confirmed by the thermal shock test and the cross-cutting and peel test. In conclusion, we made a composite material of metallic and polymeric films of high adhesion strength.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.1
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• pp.48-52
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• 2010

This paper examined the effects of specimen elongation on the electrostatic electrification voltages when polypropylene film specimens with 500%, 650% and 700% elongations were rotated at 1550 rpm. The results were as follows. The decease of electrification voltage was not measured according to the time elapse, in case of elongated specimens with 70% environment humidity. As +10 kV was applied to the specimens with 650% elongations, the electrostatic electrification voltages were increased by the effect of environment humidity (1.23~1,25 kV at 50~60% humidity, and 1,46 kV at 70% humidity). The voltages were decreased to 1.2 kV at 700% elongation. As -10 kV was applied to the specimens with 500%, 650% and 700% elongations, the electrostatic electrification voltages were negatively increased with the increase of environment humidity and the elongation of specimens.

• KSBB Journal
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• v.17 no.3
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• pp.235-240
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• 2002

The surface of polypropylene was modified by 1 keV $Ar^+$ ion beam in an $O_2$ environment in order to enhance wettability. Contact angle of deionized water on modified polypropylene was reduced from $78^{\circ}$to $22^{\circ}$. The enhanced wettability is originated from newly formed functional groups such as ether, carbonyl, and carbonyl groups. During immersion in deionized water, the enhanced wettability has remained nearly same. After washing in water, the hydrophilic functional groups on the polymer surface have been very stable. The modified polypropylene was adopted as bio-film media to remove organics in synthetic wastewater. Microbe adhesion on the polypropylene surface was improved due to the newly formed hydrophilic groups.