• 한국염색가공학회지
• /
• 제33권4호
• /
• pp.258-268
• /
• 2021

This study conducted on the introduction of recycled cellulose fibers, which are widely used in the textile industry as eco-friendly biomass materials, into polypropylene resins, which are mainly used for interior and exterior materials such as door trims and console parts of automobiles. In general, cellulose fibers can affect mechanical properties and have a lightening effect when used as a reinforcing agent. However, since cellulose fibers have hydrophilic properties and have relatively low compatibility with industrial polymer resins, they are used in combination through fiber hydrophobic surface treatment. Therefore, through this study, the reforming reaction conditions optimized in terms of hydrophobicity and workability for cellulose fibers are studied. Furthermore, polypropylene containing surface-modified cellulose fibers was prepared to compare physical properties by fiber content and study optimized content.

• The Journal of Advanced Prosthodontics
• /
• 제4권1호
• /
• pp.30-36
• /
• 2012

PURPOSE. The aim of this in-vitro investigation was to describe the effect of reinforcement with different fibers on impact strength of heat polymerized poly-methyl methacrylate (PMMA) denture base resin and to analyze the effect of surface treatment of the fibers on the impact strength. MATERIALS AND METHODS. The specimens were fabricated from the dies formed as per standard ASTM D4812. 2% by weight of glass, polyethylene and polypropylene fibers were incorporated in the PMMA resin. The Izod impact testing was performed on the unnotched specimens and the values obtained were analyzed using appropriate one way ANOVA, followed by unpaired t-test. Fractured ends of the samples were subjected to the SEM analysis. RESULTS. The polypropylene fibers with plasma treatment showed the highest impact strength ($9.229{\times}10^2$ J/m) followed by the plasma treated polyethylene fibers ($9.096{\times}10^2$ J/m), untreated polypropylene fibers ($8.697{\times}10^2$ J/m), untreated polyethylene fibers ($7.580{\times}10^2$ J/m), silane treated glass fibers ($6.448{\times}10^2$ J/m) and untreated glass fibers ($5.764{\times}10^2$ J/m). Also the surface treatment of all the fibers has shown the significant improvement in impact strength. Findings of the SEM analysis justified the improvement in impact strength after surface treatment. CONCLUSION. Reinforcement with the fiber is an effective method to increase the impact strength of PMMA denture base resin. The surface treatment of fibers further increases the impact strength significantly.

• 한국염색가공학회지
• /
• 제25권2호
• /
• pp.102-109
• /
• 2013

A new series of anthraquinoid magenta dyes having alkylphenyl substituents was synthesized and applied toward pure polypropylene fibers. The affinity of the dyes toward polypropylene fibers was increased gradually with the increase of the length of alkyl substituents. The optimum length of alkyl group was determined as heptyl substituents from the practical point of view. The color values of the dyes on polypropylene fabrics displayed slight bluish red, namely magenta which is more practical than primary red in color matching. The good fastness ratings to washing, rubbing and light were obtained for the dyes having longer alkyl groups than hexyl substituents. Expecially they exhibited ratings 4 of light fastness, which is higher than primary red dyes previously reported.

• Structural Engineering and Mechanics
• /
• 제60권2호
• /
• pp.211-223
• /
• 2016

Static loading and fluid impact tests on plates containing mesh reinforcement and polypropylene fibers in ratios of 0 to 3% by volume were performed. The objective was to observe the effect of fluid mass on the total impulse that caused the impact event and the influence of fiber amount on the impact resistance, and to estimate the velocity of fluid that causes scabbing, perforation or total disintegration. The study is the first to express the fluid impact resistance of polypropylene fiber reinforced concrete plates.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1996년도 가을 학술발표회 논문집
• /
• pp.321-327
• /
• 1996

The result of an experimental study on the mechanical properties of different types of polypropylene fiber reinforced concrete are presented in this paper. This study has been performed to obtain the properties of PFRC such as slump, Vee-Bee time, compressive strength, tensile strength, flexural strength, toughness and resistance to impact. The test variables are fiber content, fiber types, fiber length and W/C ratio. Polypropylene fibers were effective in reinforcing the matrix. A remarkable increase in toughness was observed by the addition of polypropylene fibers.

• Advances in materials Research
• /
• 제8권2호
• /
• pp.137-154
• /
• 2019

In this study, thermal effects on the mechanical properties of cement mortars with some types of fibers is investigated. The replaced fibers were made of polypropylene (PP), aramid, glass and basalt. In other words, the main goal of this paper is to study the effects of different fibers on the mechanical properties of cement mortars after subjecting to normal and sub-elevated temperatures. The experimental tests used for investigating these effects were compressive, splitting tensile, and four-point bending tests at 20, 100 and $300^{\circ}C$, respectively. Moreover, the microstructures of the specimens in different temperatures were investigated using scanning electron microscope (SEM). Based on the experimental results, the negative effects of sub-elevated temperatures on four-point bending tests were much more than the others. Moreover, using the fibers with higher melting points could not improve the qualities of the samples in sub-elevated temperatures.

• 콘크리트학회논문집
• /
• 제20권6호
• /
• pp.747-754
• /
• 2008

본 연구에서는 강섬유 혹은 폴리프로필렌 섬유로 하이브리드 보강되고, 수직하중과 수평하중을 받는 고강도 콘크리트 내민받침을 제작하고 실험하였다. 실험 결과, 강섬유, 폴리프로필렌 섬유를 혼입함에 따라 내하력, 강성, 연성, 균열폭, 균열 수 측면에서 고강도콘크리트 내민받침의 성능은 향상되었다. 폴리프로필렌 섬유로 보강된 고강도콘크리트 내민받침은 강섬유로 보강된 내민받침보다 다소 낮은 내하력을 보였지만, 수평하중 하에서 더 큰 연성을 보였다. 또한, 주인장 타이 철근으로 사용된 헤디드 바의 헤드는 뛰어난 정착을 보여주었다. 실험 결과를 설계기준의 규준식 및 여러 연구자들이 제안한 예측모델과 비교한 결과, 정밀 스트럿-타이 모델이 수평하중 하에서 가장 정확하고 보수적인 예측 결과를 보여주었고, Fattuhi가 제안한 트러스 모델은 섬유 보강 고강도콘크리트 내민받침의 강도를 잘 예측하는 것으로 나타났다.

• 터널과지하공간
• /
• 제20권5호
• /
• pp.378-389
• /
• 2010

해저에 시공되는 터널은 일반시공보다 환경에 더 많은 영향을 받는다. 특히 해수의 침입에 따른 염해의 위험에 노출되어 있으며, 이는 콘크리트에 포함된 철근과 강섬유의 부식에 큰 영향을 미친다. 해수 침투에 따른 염해 가능성이 염려되는 터널에서 최근 내부식성 섬유로 그 활용도가 증가하고 있는 폴리프로필렌섬유를 대상으로 강섬유와의 성능 비교를 통하여 적정 배합비를 결정하고, 원형패널 시험과 휨인성 시험을 통해 지보재로서의 성능을 평가하였다. 본 연구의 결과는 해저에 시공되는 터널에서 섬유보강재의 선택 및 섬유보강 숏크리트 설계에 활용될 수 있을 것으로 판단된다.

• 접착 및 계면
• /
• 제7권2호
• /
• pp.1-11
• /
• 2006

미처리 Jute와 Hemp섬유와 처리된 Jute와 Hemp섬유가 강화된 polypropylene-maleic anhydride-g-polypropylene copolymer (PP-MAPP) 복합재료의 계면 물성을 미세역학시험법과 동적접촉각 측정을 통해서 평가하였다. Jute와 Hemp섬유의 통계적인 인장강도의 경우 두 형태 와이블 분포가 단일 형태 분포보다 더 일치하는 것을 확인할 수 있었다. 천연섬유 복합재료의 계면전단강도(IFSS)에 대한 산-염기 상호작용변수는 접착일($W_a$)의 계산을 통해 그 특성을 기술 할 수 있다. 천연섬유에 대한 알칼리, 실란커플링제의 영향은 PP-MAPP 기지재의 MAPP 함량을 변화시킴으로써 얻을 수 있었다. 알칼리 처리된 Jute와 Hemp섬유의 경우 약한 계면층이 모두 제거되고 표면적이 증가됨으로 인해 표면에너지는 더 증가하였다. 반면 실란 커플링제를 이용하여 표면 처리된 Jute와 Hemp 섬유의 경우 차단된 높은 에너지의 기들로 인해 표면에너지는 감소하였다. PP-MAPP기지재속의 MAPP의 함량증가는 산-염기 기의 도입으로 인해 표면에너지는 증가하였다. 두 천연섬유 복합재료의 미세파괴 형상은 두 섬유의 인장강도가 다르기 때문에 명확히 구분되었다.

• 한국염색가공학회지
• /
• 제22권1호
• /
• pp.1-7
• /
• 2010

The five new red disperse dyes for unmodified pure polypropylene fibers were synthesized. As a coupling component, a di-n-hexyl substituent was used in common, while various substituents were used for the diazo component. The dye having electron donating group at diazo component showed hypsochromic shift compared to the unsubstituted dye, while the dyes having electron withdrawing groups showed bathochromic shift. Owing to their extreme hydrophobicity caused by the di-n-hexyl substituent, all dyes exhibited very high affinity toward pure polypropylene fibers. Fastness to washing was very good for all dyes and fastness to light was good except two purplish red dyes.