• Carbon letters
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• 제25권
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• pp.60-67
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• 2018

In the present work, capability of thymolphthalein-grafted graphene oxide, which was successfully synthesized in this study, in stabilization of polypropylene against thermal oxidation were investigated and compared with that of SONGNOX 1010, a commercially used phenolic antioxidant for the polymer. The modified graphene oxide were incorporated into polypropylene via melt mixing. State of distribution of the nanoplatelets in the polymer matrix was examined using scanning electron microscopy and was shown to be homogeneous. Measurements of oxidation onset temperature and oxidative induction time revealed that thymolphthalein-grafted graphene oxide modifies thermo-oxidative stability of the polymer in the melt state remarkably. However, the efficiency of the nanoplatelets in stabilization of polypropylene against thermal oxidation in melt state was shown to be inferior to that of SONGNOX 1010. Furthermore, oven ageing experiments followed by Fourier transform infrared spectroscopy showed that the modified graphene oxide improves thermo-oxidative stability of the polymer strongly in the solid state, so that its stabilization efficiency is comparable to that of SONGNOX 1010.

• 공업화학
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• 제10권1호
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• pp.46-50
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• 1999

본 연구에서는 표면이 개질된 목분으로 강화된 PP수지 복합체의 $(NH_4)_2HPO_4$과 boron 혼합물($Na_2B_4O_7:H_3BO_3=5:1\;ratio$)에 대한 난연특성에 관해 알아보았다. 또한 m-phenylene dimaleimide(PDMI)로 개질된 PP수지와 비개질된 PP수지 복합체의 기계적 특성을 비교하였다. $(NH_4)_2HPO_4$로 개질된 복합체의 난연성은 boron 혼합물로 개질된 복합체의 난연성보다 우수하였다. 복합체의 충격강도는 목분의 함량이 증가함에 따라 증가되었고, 인장강도는 감소하였다. 개질된 PP수지 복합체의 기계적 강도는 비개질된 수지의 복합체보다 개선되었다. 또한 난연제의 농도가 증가함에 따라 인장강도는 점진적으로 증가되었고, 25 wt %에서 최대값을 나타내었으며, PDMI의 함량이 증가함에 따라 목분-PP 복합체의인장강도는 16 wt %까지 증가되었다.

• Carbon letters
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• 제27권
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• pp.81-89
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• 2018

The present study aimed to prepare a novel efficient flame retardant additive for polypropylene. The new flame retardant was prepared by chemical grafting of melamine to graphene oxide with the aid of thionyl chloride. Fourier-transform infrared spectroscopy and thermogravimetric analysis proved that melamine had been successfully grafted to the graphene oxide. The modified graphene oxide was incorporated into polypropylene via solution mixing followed by anti-solvent precipitatio. Homogeneous distribution as well as exfoliation of the nanoplatelets in the polymer matrix was observed using transmission electron microscopy. Thermogravimetric analysis showed a significant improvement in the thermo-oxidative stability of the polymer after incorporating 2 wt% of the modified graphene oxide. The modified graphene oxide also enhanced the limiting oxygen index of the polymer. However, the amount of improvement was not enough for the polymer to be ranked as a self-extinguishing material. Cone calorimetry showed that incorporating 2 wt% of the modified graphene oxide lowered total heat release and the average production rate of carbon monoxide during burning of the polymer by as much as 40 and 35%, respectively. Hence, it was concluded that the new flame retardant can retard burning of the polymer efficiently and profoundly reduce suffocation risk of exposure to burning polymer byproducts.

• 한국염색가공학회지
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• 제13권6호
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• pp.405-412
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• 2001

In order to impart dyeability on to Polypropylene fiber, PP/EVA blend in the form of fibers and film were preparared using melt blending process. Ethylene vinylacetate containing 28wt% of vinylacetate(EVA(28)) was used as a copolymer. In the study of mechanical properties, tenacity and initial modulus decreased with Increasing EVA concentrations, whilst extension at break increased with increasing EVA contents. Their results in the dyeing behavior show that dye adsorption increased with increased EVA contents iota both blend fibers and films. The extent of dye uptake of red dye to modified polypropylene fibers was greater than that of Blue and Yellow counterparts due to the difference behavior of dye particles in dyeing bath.

• 한국염색가공학회지
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• 제13권6호
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• pp.47-47
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• 2001

In order to impart dyeablility on to Polypropylene fiber, PP/EVA blend in the form of fibers and film were preparared using melt blending process. Ethylene vinylacetate containing 28wt% of vinylacetate(EVA(28)) was used as a copolymer. In the study of mechanical properties, tenacity and initial modulus decreased with increasing EVA concentrations, whilst extension at break increased with increasing EVA contents. Their results in the dyeing behavior show that dye adsorption increased with increased EVA contents for both blend fibers and films. The extent of dye uptake of red dye to modified polypropylene fibers was greater than that of Blue and Yellow counterparts due to the difference behavior of dye particles in dyeing bath.

• Elastomers and Composites
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• 제57권2호
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• pp.40-47
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• 2022

The effects of maleic-anhydride-grafted polypropylene (PP-g-MAH) and montmorillonite (MMT) on the wear resistance of polypropylene (PP) were investigated. The surface of MMT was modified with 3-aminopropyltriethoxysilane, and the interfacial interaction between PP and MMT was improved using PP-g-MAH. Fourier-transform infrared spectroscopy was used to confirm that silane was grafted on the surface of MMT. The Taber abrasion test and scanning electron microscopy were used to determine the wear resistance and observe the surface morphology of PP, respectively, after wear testing. Energy-dispersive X-ray spectroscopy was used to compare the effects of PP-g-MAH and silane modification of MMT on the dispersion of MMT. The results indicated that silane was successfully grafted onto the surface of MMT. Moreover, the wear resistance of PP was improved by the addition of MMT. The wear resistance of PP composites comprising silane-modified MMT and PP-g-MAH was higher than those of other PP composites. This was attributed to silane improving the interfacial interaction between MMT and PP.

• Fibers and Polymers
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• 제4권4호
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• pp.210-214
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• 2003

Siloxylated polypropylene fibers composed of polypropylene (PP) and aluminosiloxane (AS) were prepared by melt blending followed by spinning. The effects of blend compositions on the thermal behaviors, surface and tensile properties of PP/AS blend fibers were investigated by DSC, WAXD, SEM, static honestometer, etc. The heat of fusion of PP/AS blends decreased with increasing AS contents. In addition, the peak intensity of PP/AS blends in X-ray diffraction patterns decreased with increasing AS contents. It was observed that the silicone molecules exist and well distribute on the surface of siloxylated polypropylene fibers. From the results of the half-life period measurements, the anti-static properties of PP fibers siloxylated with AS was found to be significantly modified.

• 한국염색가공학회지
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• 제21권1호
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• pp.46-52
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• 2009

Dyeing properties of hydrophobic polypropylene fibers using cationic dyes were investigated to improve dyeability by electron beam irradiation and sulfonic acid incorporation. The color strength of irradiated polypropylene fibers was examined according to the dyeing conditions including pH of dyebath, absorbed doses, and introduction of functional group to fiber substrate. The best dyeing result was obtained when sulfonic acid group incorporated polypropylene fibers after electron beam irradiation were dyed with cationic dyes at alkaline conditions and 30$\sim$75kGy irradiation ranges.

• Elastomers and Composites
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• 제41권1호
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• pp.49-56
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• 2006

Allylamine을 이용하여 UV하에서 폐타이어 분말을 개질하였으며, 이를 이용한 PP/폐타이어분말 복합체의 열적, 유변학적 성질을 분석하였다. X-ray 분석결과 무수말레 산이 그라프트된 폴리프로필렌과 같은 상용화제가 없는 경우 ${\beta}$ 결정의 피크 강도가 증가한 반면 상용화제가 있는 경우 완전히 없어짐을 알 수 있었으며, DSC 결과에서도 이를 확인할 수 있었다. 개질된 폐타이어 분말을 함유한 복합체의 용융점도와 탄성모듈러스는 개질되지 않은 분말을 함유한 복합체 보다 높은 값을 나타내었으며, 이는 개질된 분말 표면의 아민기와 말레이산이 그라프트된 PP의 상호작용에 기인하는 것으로 판단된다.

• 폴리머
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• 제30권4호
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• pp.318-325
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• 2006

아미노 실란이 도입된 기능성 클레이를 제조하고, 이를 폴리프로필렌과 상용화제인 무수 말레인산이 그래프트 중합된 폴리프로필렌과 함께 용융 혼합법으로 공유 결합이 형성된 폴리프로필렌/클레이 나노복합체를 제조하였다. 아미노 실란으로 개질된 클레이의 구조 및 표면 특성은 각각 엑스선 회절 분석, 적외선 분광 분석, 그리고 고체상태 핵자기 공명 분석 결과를 통해 확인하였다. 아미노 실란을 이용한 클레이의 개질은 약 $19.8{\AA}$ 의 실리케이트 층간 거리를 증가시켰으며, 클레이 층상에 존재하는 히드록시기의 $3650cm^{-1}$ 에 존재하는 피크의 강도가 약해지는 것을 확인하였으며, 아민 그룹이 치환된 Si를 의미하는 -69 ppm 부근의 시그널도 확인하였다.