• Composites Research
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• 제37권2호
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• pp.68-75
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• 2024

경제성과 가공 시 용이성 등의 장점을 가지는 합성수지는 자연상태에서 분해되지 않고 환경오염을 야기 시키는 문제를 가진다. 이러한 문제를 해결하기 위해 재활용이 가능한 열가소성 수지가 주목되고 있고 그 중 경제성이 뛰어난 폴리프로필렌(PP)에 대한 관심이 높아지고 있다. PP의 경우 기계적 특성 및 열안정성 등과 재활용성이 뛰어나다. 하지만 다수의 문헌에서 열가소성 수지의 반복 가공에 따라 물성의 저하가 일어난다는 것을 확인 할 수 있으며 가공 조건에 따라 품질의 저하가 발생하는 시점이 다르다는 것을 확인할 수 있다. 따라서 본 연구에서는 PP 수지에 여러 첨가 성분을 블렌딩하여 복합 조성물 제조 시 반복 공정에 의한 성능 변화를 평가하기 위해 압출 공정 및 사출 공정을 반복 진행하여 기계적 특성 및 열적 특성을 평가하고자 한다. 또한 반복 공정 시 MFI 값 변화에 따라 복합재료 공정 시 섬유의 함침에 어떤 영향을 주는지에 대해 평가하기 위해 복합재료의 기계적 물성을 평가하고자 한다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.181-184
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• 2005

Experimental results on lap splice performance of high performance fiber reinforced cementitious composite(HPFRCC) with fiber types under repeated loading are reported. Fiber types were polypropylene(PP), polyethylene(PE) and hybrid fiber[polyethylene fiber+steel cord(PE+SC)]. The development length($l_d$) was calculated according to the relevant ACI code requirements for reinforcing bars in concrete. The current experimental results demonstrated clearly that the use of fibers in cementitious matrixes increases significantly the splice strength of reinforcing bars in tension. Also, the presence of fibers increased the number of cracks formed around the spliced bars.

• Composites Research
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• 제20권3호
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• pp.55-62
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• 2007

Jute와 Hemp 섬유/폴리프로필렌 (PP)의 내구성 및 계면 평가는 끓는 물 실험 전 후로 해서 조사되었고 끓는 물 실험 전 후에 따른 Jute와 Hemp 섬유의 수분함량은 TCA를 통해 측정되었다. 끓는 물 실험 후, Jute, Hemp섬유와 폴리프로필렌 기지재 사이의 계면전단강도와 기계적 물성은 감소하였다. 반면에 물에 의해 부풀어 오른 미소섬유에 의해 미처리경우와 비교해서 접착일은 증가를 하였다. 그리고 끓는 물 실험 전·후의 Jute, Hemp섬유와 폴리프로필렌의 표면에너지는 동 접촉각을 통해 얻어졌다. 계면전단강도는 항상 열역학의 접착일과 일치하지는 않는다. 끓는 물 내에서, Jute와 Hemp 섬유는 물에 의해 부풀어지게 된다. 그래서 표면적과 수분 침투공간이 증가한다. 끓는 물 실험 전 후의 Jute와 Hemp 섬유 미세파괴 경향은 명백하게 다르다. Jute와 Hemp 섬유/폴리프로필렌 복합재의 환경적 영향에 의한 미세파괴 형태는 광학 현미경을 통한 관찰과 음향 방출 수와 에너지에 의해 상호 일치함을 보여주었다. 끓는 물 실험 이후, Jute 섬유는 Hemp 섬유와 달리 부풀어진 피브릴에 의한 낮은 인장강도에서 나타나는 미세파괴 형태를 보여주었다. 또한, 부풀어진 피브릴에 의해 미세파괴시 음향 방출 수는 증가를 하였으며, AE 진폭과 에너지는 감소하였다.

• 대한기계학회논문집A
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• 제30권7호
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• pp.794-799
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• 2006

In recent years, the use of natural fiber as reinforcement in polymer composites to replace synthetic fiber such as glass fiber is receiving increasing attention. Because of increasing usage according to the high demand, the cost of thermoplastic has increased rapidly over the past decades. We used a thermoplastic polymer(polypropylene) as the matrix and a lignocellulosic material(rice-husk flour) as the reinforcement filler to prepare a particle-reinforced composite to examine the possibility of using lignocellulosic material as reinforcement filler and to determine data of test results for physical, mechanical and morphological properties of the composite according to the reinforcement filler content in respect to thermoplastic polymer, In this study, PLA/PP rice-husk fiber-reinforced thermoplastic composites that made by the hot press molding method according to appropriate manufacturing process was evaluated as mechanical properties.

• International Journal of Advanced Culture Technology
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• 제3권2호
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• pp.25-33
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• 2015

This study aims to synthesis the self-cleaning fibers. The nano-titanium dioxide ($TiO_2$) were blend with the polypropylene (grade 561R) at 1wt%, 3wt%, 5wt%, 10wt%, 15wt% and 20wt%. The $TiO_2$-fibers were obtained from single screw extruder. The mechanical, thermal, rheology and self-cleaning properties were also investigated. The results showed that the tensile strength of the $nTiO_2$-PP fibers decreased with increasing of the amount of $TiO_2$. The presents of the $TiO_2$ in the PP fibers significantly showed the improving of the self-cleaning properties under sunlight and 20 watt of UV radiation. The $TiO_2$-PP fibers in presents of $TiO_2$ 20wt% showed the best results of self-cleaning under 5 hours of the sunlight which the similar results were found under 5 hours of 20 watts of UV radiation.

• Carbon letters
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• 제15권3호
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• pp.203-209
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• 2014

The adsorption of volatile organic compounds (VOCs) was carried out using an activated carbon fiber (ACF) filter in an automobile. The adsorption capacities of formaldehyde, toluene, and benzene on an ACF filter were far better than those of a polypropylene (PP) mat filter and combined (PP+activated carbon) mat filter by batch adsorption in a gas bag. In a continuous flow of air containing toluene vapor through an ACF packed bed, the breakpoint time was very long, the length of the unused bed was short, and sharp "S" -type breakthrough curve was plotted soon after breakpoint, showing a narrow mass transfer zone of toluene on the ACF. The adsorption amount of toluene on the ACF filter was proportional to the specific surface area of the ACF; however, the development of mesopores 2-5 nm in size on the ACF was very effective with regard to the adsorption of toluene. The ACF air clarifier filter is strongly recommended to remove VOCs in newly produced automobiles.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2006년도 추계 학술논문 발표대회 논문집
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• pp.103-106
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• 2006

This study investigates spalling properties of 60MPa class, high performance concrete, made with the various influential parameters, such as, blaine of cement, mineral admixture and polypropylene(PP) fiber contents. Totally 21 parameters of ${\phi}100{\times}200mm$ in size was fabricated; three specimens for variance in blaine of cement, 4 specimens for combination of mineral admixture type, along with 0.05, 0.1, 0.15% of fiber adding ratio. After that, one hour unloading fire test was conducted, and then spalling appearance and spalling degree of specimens was examined. Test showed that a specimen made with high blaine of cement(H) improved early strength but exhibited similar value to a specimen made with low blaine(L) at the age of 28 days, thus indicating comparable spalling appearance. In conclusion, spalling easily occur in higher strength and smaller particle shape of cement and mineral admixture.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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• pp.417-418
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• 2010

본 연구는 3시간 내화실험으로 고강도콘크리트의 화재저항성을 파악하는데 그 목적이 있다. 섬유의 종류(폴리프로필렌, 나일론)와 콘크리트 피복두께(40mm, 50mm, 60mm)를 조절하여 실험을 하였다. 실험결과 충분한 양의 섬유를 혼입하였을 때 폭렬 저항성을 갖는 것으로 나타났다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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• pp.32-33
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• 2019

This study evaluated the effect of amorphous steel fibers on the spalling characteristics of high-strength concrete. with mix proportions of polypropylene (PP) fibers of 0.15% by concrete volume, and proportions of amorphous steel fibers of 0.3% and 0.5% by concrete volume. In the range of 0.3 vol% of amorphous steel fiber, the effect of suppression of the spalling and the prevention of degradation of strength was shown, but it was evaluated to be ineffective in the suppression of the spalling due to interferences in formation of pore network in the range of 0.5 vol.%.

• 한국산업융합학회 논문집
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• 제5권1호
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• pp.27-32
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• 2002

In this study, estimate of Mechanical Properties depending on Injected direction in Polymer for Automobile Application. The used materials is polyamid(nylon6), polypropylene(PP) of a simple component and its mixed, reinforced glass fiber(15%) in polyamid. One side direction of a simple component is highest strength and the two sides direction of multicomponent appear lowest strength. This is caused by effects of weldline, imperfect fusion and impregnation of multicomponent. To improve mechanical properties, it is necessary to minimize of weldline, compatibility, perfect fusion and impregnation in multicomponent polymer.