• 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.

• 접착 및 계면
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• 제7권2호
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• pp.1-11
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• 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.

• 한국의류산업학회지
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• 제20권5호
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• pp.600-607
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• 2018

Polypropylene fibers, while having many advantages such as light weight, sweat fast drying, water-repellent, drainage, thermal insulation, anti-static property has a drawback in dyeing. In recent years, the development of dyeable polypropylene fibers has expanded its value in the textile market. The purpose of this study is to fabricate composite spun yarns using polypropylene, acrylic, rayon and wool and to analyze tensile properties, uniformity characteristics, bending properties, hairiness, and surface shape according to the degree of fineness and blended ratio. The specimens consisted of 100% polypropylene spun yarn pp30, pp40 and ppa(pp/acrylic), ppr(pp/rayon), ppw(pp/wool), 5 altogether sed in this study. The results of the study are as follows. The breaking strength of polypropylene spun yarn blended with rayon and acrylic was higher than that of 100% polypropylene spun yarn. The polypropylene spun yarn is higher the fineness been shown to decrease the breaking strength and elongation. The bending properties of polypropylene spun yarns were in the order of ppa>ppr>pp40>pp30>ppw. The unevenness of ppw, ppr, and ppa was higher than pp40 and pp30. With the exception of ppw with crimp properties, pp30 and pp40 were found to have a hairiness index greater than ppr, ppa. In the microscopic photographs of polypropylene spun yarn, pp30, which had the highest hairiness index, was found to have a thick yarn and a large number of hairs, and ppw had hairs of 3 mm or more protruding elongated outwardly.

• 한국조경학회지
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• 제46권6호
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• pp.120-126
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• 2018

본 연구는 콘크리트에 잔골재와 폴리프로필렌섬유를 혼입한 실험과 화강토와 폴리프로필렌섬유를 혼입한 실험을 하였다. 특히 두 종류의 실험은 폴리프로필렌섬유의 양을 변경하여 슬럼프, 압축강도, 인장강도 등의 역학적 특성에 대하여 실험적으로 규명하였다. 두 종류의 실험 결과를 비교하여 잔골재를 실험 재료로 사용한 경우와 화강토를 사용한 재료를 비교 분석하여 건조 수축 균열로 인한 부분적인 파괴를 예방하고, 가벼워서 사용하기 편한 품질 좋은 조경용 구조물 및 포장재 개발의 기초자료를 수립하는데 목적이 있다. 콘크리트에서 PP 섬유의 양이 증가할수록 PP 섬유의 체적 또한 현저히 증가하게 되므로 슬럼프가 감소해지는 것으로 판단된다. 압축강도의 결과, 화강토콘크리트는 콘크리트 강도의 59%~71% 정도로 측정되었다. PP 섬유의 혼입량이 증가할수록 압축강도는 상대적으로 줄어드는 경향이 나타났다. 인장강도의 결과 화강토 콘크리트는 콘크리트 인장강도의 68%~67% 정도로 나타났다. PP 섬유를 콘크리트나 화강토콘크리트에서 혼입량을 증가시킬수록 압축강도가 감소하는 것으로 나타났다. 그리고 콘크리트와 화강토콘크리트에 폴리프로필렌섬유를 혼입하면 인장강도가 증가하는 것으로 나타났다. 이러한 결과들을 분석해 화강토를 혼입한 콘크리트에 일정량의 PP섬유를 혼입하여 조경분야의 각종 구조물 또는 포장과 관련된 재료에 활용하면 구조물의 취성에 의한 파괴 및 균열로 인한 박리 박락의 방지 개선효과가 있을 것으로 판단된다.

• 한국염색가공학회지
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• 제25권3호
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• pp.165-171
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• 2013

A new monoazo violet dye optimized for polyolefin fibers such as polypropylene and ultra high molecular weight polyethylene fibers was synthesized and its dyeability was investigated. Two hexyl groups were introduced to coupler, 2,5-dimethoxyaniline, in order to increase hydrophobicity of the dye. The maximum absorption wavelength was appeared at 580nm, which meant that the dye showed violet color. From the dyeing results at various conditions, the optimum dyeing was determined as $130^{\circ}C$ for 1 hour with 5% owf of dyes. The good fastness ratings to washing, rubbing were obtained showing at least 4 for both fibers. Light fastness was acceptable for polypropylene fibers giving ratings 3~4. However, relatively poor light fastness was obtained in case of ultra high molecular weight polyethylene fibers showing ratings 2.

• 한국염색가공학회지
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• 제10권5호
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• pp.13-18
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• 1998

Polypropylene-ethylene/vinyl acetate copolymer (PP-EVA) blends were prepared by mechanical blending using relatively semi-crystaline ethylene-vinyl acetate copolymer and polypropylene. In order to obtain dyeable PP fiber, PP-EVA blends were prepared using below 10wt.％ of EVA and formed a filament by the melt spinning method. The resultant fibers had tensile strengh of 2∼3g/d, elongation of 330∼600%, initial modulus of 22∼46g/d, and exhibited markedly improved dyeing property.

• 한국의류산업학회지
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• 제16권3호
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• pp.456-461
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• 2014

The objective of this study is to give PP(polypropylene) fabric a good affinity for water. Oxygen plasma was treated to PP fabrics in a commercial glow discharge reactor with different RF power, discharge pressure, and reaction time. The PP fiber surfaces were characterized by the measurement of contact angle and ESCA. A JEOL scanning electron microscope was used to observe the surface morphology of fibers. The spontaneous water uptake amount of PP fabrics was determined by the demand wettability test. To determine the effect of aging on the surface properties of $O_2$ plasma treated PP, all the above measurements of the samples were carried out after 1, 7, 30, 60, and 150 days. The results are as follows. The PP fiber surfaces treated by $O_2$ plasma treatment have a chemical composition that consisted of various oxygen containing polar groups. Consequently, the contact angles of the treated PP fibers decreased, which improved the water uptake rate of PP fabrics. Surface roughness of the treated PP affected the fabric wettabiity as well. Wettability of the treated PP decreased and leveled off with aging. The $O_2$ plasma treatment is a simple and effective method to increase the water uptake rate of PP fabrics.

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

• Advances in materials Research
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• 제8권2호
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• pp.103-115
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• 2019

Polypropylene (PP) fibers for making fabric which is used for packing cement have a high strength and high tear resistance. Due to these excellent properties the present study investigates the effect of PP fibers on the mechanical strength of concrete. Mechanical strength parameters such as compressive strength, splitting tensile strength and flexural strength are evaluated. Structural integrity of concrete using Ultrasonic Pulse Velocity (UPV) was also studied. Concrete containing PP fibers in percentage of 0%, 0.15%, 0.25%, 0.5% and 0.75% was developed with a characteristic compressive strength of 25 MPa. Concrete cubes, cylinder and prismatic specimens were cast and tested. It was found that the UPV values recorded for all specimens were of the similar order. Test results indicated the used of PP fibers can significantly improve the flexural and splitting tensile strengths of concrete materials whereas it resulted a decreased in compressive strength. The relative increase in split tensile and flexural strength was optimum at a fiber dosage of 0.5% and a mild decreased were observed in 28 days compressive strength. The findings in this paper suggested that PP fibers deriving from these waste cement bags are a feasible fiber option for fiber-reinforced concrete productions.

• Advances in concrete construction
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• 제11권2호
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• pp.163-171
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• 2021

This paper studies the effect of using multi-scale reinforcement additives on mechanical strengths, damage performance, microstructure, and water absorption of cementitious composites. Small dosages of carbon nanotubes (CNTs) or polypropylene (PP) microfibers; 0.05%, 0.1%, and 0.2% by weight of cement; were added either separately or simultaneously into cement mortar. The experimental results show the ability of these additives to enhance the mechanical behavior of the mortar. The best improvement in compressive and flexural strengths of cement mortar reaches 28% in the case of adding a combination of 0.1% CNTs and 0.2% PP fibers for compression, and a combination of 0.2% CNTs and 0.2% PP fibers for flexure. Adding CNTs does not change the brittle mode of failure of plain mortar whereas the presence of PP fibers changes it into ductile failure and clearly enhances the fracture energy of the specimens. Scanning electron microscopic (SEM) images of the fracture surfaces highlights the role of CNTs in improving the adhesion between the PP fibers and the hydration products and thus enhance the ability of the fibers to mitigate cracks propagation and to enhance the mechanical performance of the mortar.