PP Fiber Research Articles

Preparation and characterisation of luminous polypropylene/phosphor strontium aluminate nanocomposite fibres with enhanced dyeability

Phosphor strontium aluminate (SrAl2O4: Eu2+, Dy3+) nanoparticles, SAOED, were melt compounded with polypropylene on an internal mixer to prepare a uniform mixture with polymer and the resulting materials were granulated. PP/SAOED nanocomposite fibres were then produced by melt spinning method at the take-up speed of 1000 m min−1. Morphological, thermal, structural and luminescent properties of the luminous fibres were studied by SEM, differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD) and fluorescence spectrophotometer. The luminous fibres were then knitted and dyed to investigate the effects of SAOED nanoparticles on the dyeability of fibres. SEM results showed that with increasing SAOED nanoparticle amounts, the agglomerates of SAOED nanoparticles were appeared on the fibre surface. DSC results indicated that the SAOED nanoparticles did not affect melting and crystallisation behaviours significantly. WAXD patterns revealed that the crystal type of luminous nanocomposite fibres did not change and was still the α-monoclinic crystal form. The luminous nanocomposite fibres were found to have inferior tensile properties as compared to the neat PP fibre. From fluorescence spectrophotometer results, it can be seen that fibres excited at the wavelength of 400 nm, showed an emission peak at 550 nm and had green light. With increasing the amount of SAOED nanoparticles in the fibres, emission peak intensity of luminous fibres increased and also the fabric dyeability was improved.

A study on the role of polypropylene fibers and silica nanoparticles on the compression properties of silicone rubber composites as a material of finger joint implant

ABSTRACTIn this study, different contents of SiO2 nanoparticles and polypropylene fibers were added to silicone rubber matrix as a material of finger joint implants and mechanical properties of these composites were investigated before and after being soaked in simulated body fluid. Results of compression test revealed that compression stress of silicone rubber by addition of the 2 wt% silica and 2 wt% PP fibers increased from 0.98 to 1.9 and 2.37 MPa, respectively. These stresses decreased after being soaked in SBF and water absorption results proved this. Increasing silica contents caused an increase in water absorption while increasing PP fibers showed contrary behavior.

Development of Cement Based Composites with PVA Fibers

This paper is focused on a mechanical properties of fine-grained cement based composite materials reinforced by short PVA fibers. Cementitious materials are characterized by their fragile matrix. Reinforcing by fibers (e.g. steel fibers, PVA fibers, PP fibers, glass fibers) increase the tensile strength. The behavior of the elements after developing and spreading of micro cracks under load should be described as a strain-softening, strain-hardening, etc. The multiple cracking under load is typical deformations of composite materials reinforced by short PVA fibers, that is worldwide known as a ECC.

Rheological Properties of Polypropylene Reinforced Asphalt Binder

Polypropylene fibers (PP fibers) were used as additives to prepare fiber-reinforced asphalt binders in this work, with concentrations varying from 0 to 2.5 % in increments of 0.5 % by weight of asphalt. The microstructure of fibers and dispersion of fibers in the asphalt were analyzed via scanning electron microscopy (SEM) using a ZEISS microscope at different magnification rates. Penetration, softening point, dynamic shear rheometer (DSR), and Multiple Stress Creep Recovery (MSCR) tests were conducted to study the rheological properties and the results are compared. With the increase in the dosage of PP fibers, the penetration values were decreased while the softening points increased. Complex shear modulus was increased and phase angles were decreased. The Strategic Highway Research Program (SHRP) rutting parameter G*/Sinδ and the Shenoy’s rutting parameter, G*/(1 − (1/sinδ.tanδ)), were improved with fibers. MSCR results indicate that the non-recoverable creep compliance (Jnr) and percent of recovery (R%) are decreased and increased, respectively, with the addition of fibers. The results indicate that the asphalt with PP fiber reduces thermal sensitivity and increased resistance to permanent deformation at high temperatures. The Shenoy’s rutting parameter has better correlation with non-recoverable creep compliance (Jnr) and it can be considered as a better rutting predictor than G*/Sinδ for fiber modified asphalt binders.

The effect of carbon nanotubes and polypropylene fibers on bond of reinforcing bars in strain resilient cementitious composites

Stress transfer between reinforcing bars and concrete is engaged through rib translation relative to concrete, and comprises longitudinal bond stresses and radial pressure. The radial pressure is equilibrated by hoop tension undertaken by the concrete cover. Owing to concrete’s poor tensile properties in terms of strength and deformability, the equilibrium is instantly released upon radial cracking of the cover along the anchorage with commensurate abrupt loss of the bond strength. Any improvement of the matrix tensile properties is expected to favorably affect bond in terms of strength, resilience to pullout slip, residual resistance and controlled slippage.The aim of this paper is to investigate the local bond of steel bars developed in adverse tensile stress conditions in the concrete cover. In the tests, the matrix comprises a novel, strain resilient cementitious composite (SRCC) reinforced with polypropylene fibers (PP) with the synergistic action of carbon nano-tubes (CNT). Local bond is developed over a short anchorage length occurring in the constant moment region of a four-point bending short beam. Parameters of investigation were the material structure (comprising a basic control mix, reinforced with CNTs and/or PP fibers) and the age of testing. Accompanying tests used to characterize the cementitious material were also conducted. The test results illustrate that all the benefits gained due to the synergy between PP fibers and CNTs in the matrix, namely the maintenance of the multi-cracking effect with time, the increased strength and deformability as well as the highly increased material toughness, were imparted in the recorded bond response. The local bond response curves thus obtained were marked by a resilient appearance exhibiting sustained strength up to large levels of controlled bar-slip; the elasto-plastic bond response envelope was a result of the confining synergistic effect of CNTs and the PP fibers, and it occurred even without bar yielding.

리브를 갖는 FRP 판과 고인성섬유보강콘크리트로 이루어진 합성보의 파괴거동에 대한 실험적 연구

고인성섬유보강콘크리트는 기존의 콘크리트에 비해 인성을 크게 개선한 재료로써, 콘크리트 구조물의 여러 분야에 적용 가능한 건설 신재료로 평가되고 있다. 본 연구에서는 고인성섬유보강콘크리트와 리브를 갖는 FRP 판을 인장 보강재 및 영구거푸집으로 활용한 합성보의 파괴거동에 관한 실험을 실시하였다. 비교를 위해 일반콘크리트와 PVA계열인 RF4000과 PP계열인 PP-macro의 섬유를 사용하였으며, 각각 RF4000+RSC15, PP-macro+RSC15를 혼입하여 합성보를 제작하여 실험하였다. FRP 판에 잔골재를 미부착한 경우는 보의 중앙에 발생한 휨 균열이 크게 벌어지면서 FRP 판과 콘크리트가 미끄러짐에 의한 파괴형태를 보여주고 있음으로 잔골재 부착은 필수적 사항이라 판단되며, 파괴모드에 대한 섬유보강재의 영향은 크지 않은 것으로 판단된다. FRP 판에 잔골재를 부착한 실험 결과는 1200, 2000mm 모두 콘크리트와 FRP 사이에 충분한 부착이 형성되었다. 일반콘크리트보다 섬유보강재를 혼입한 경우 최대 하중이 높게 나타났고, 그 중 PP계열의 섬유보강재를 혼입한 경우 최대 하중이 가장 높게 나타났다. 균열이 섬유보강재에 의해 지연되면서 FRP 리브와의 합성작용에 의해 발생한 것으로 판단된다. DFRCC (ductile fiber reinforced cementitious composites), which are a significantly improved ductile material compared to conventional concrete, were evaluated as a new construction material with a high potential applications to concrete structures for a range of purposes. In this study, experiments on the failure behavior of composite beams with a DFRCC and FRP (fiber reinforced polymer) plank with a rib used as permanent formwork and tensile reinforcement were carried out. A normal concrete and a fiber reinforced concrete with PVA series of RF4000 and the PP series of PP-macro were used for comparison, and each RF4000+RSC15 and PP-macro+RSC15 was tested by producing composite beams. The experimental results of the FRP plank without a sand coating showed that sliding failure mode between the FRP plank and concrete started from a flexural crack at the beam center; therefore it is necessary for the FRP plank to be coated with sand and the effect of the fiber to failure mode did not appear to be huge. The experiment of the FRP plank with a sand coating showed that both 1200mm and 2000mm allowed sufficient bonding between the concrete and FRP plank. The maximum load of the fiber reinforced concrete was higher than that of normal concrete and the case which a series of PP fiber was mixed showed the highest value. The crack latency caused by the fibers led to composite action with a FRP rib.

Influence of different fibers on the change of pore pressure of self-consolidating concrete exposed to fire

The focus of this paper is given to investigate the effect of different fibers on the pore pressure of fiber reinforced self-consolidating concrete under fire. The investigation on the pore pressure-time and temperature relationships at different depths of fiber reinforced self-consolidating concrete beams was carried out. The results indicated that micro PP fiber is more effective in mitigating the pore pressure than macro PP fiber and steel fiber. The composed use of steel fiber, micro PP fiber and macro PP fiber showed clear positive hybrid effect on the pore pressure reduction near the beam bottom subjected to fire. Compared to the effect of macro PP fiber with high dosages, the effect of micro PP fiber with low fiber contents on the pore pressure reduction is much stronger. The significant factor for reduction of pore pressure depends mainly on the number of PP fibers and not only on the fiber content. An empirical formula was proposed to predict the relative maximum pore pressure of fiber reinforced self-consolidating concrete exposed to fire by considering the moisture content, compressive strength and various fibers. The suggested model corresponds well with the experimental results of other research and tends to prove that the micro PP fiber can be the vital component for reduction in pore pressure, temperature as well spalling of concrete.

Mechanical Properties of Gypsum Matrix Reinforced with Recycled Fibers

This paper deals with using resonance method for determine a development of mechanical properties of gypsum matrix reinforced with steel fibers from recycled tires. Mechanical properties which were monitored are the dynamic Young's modulus and dynamic shear modulus. Both properties were measured by a resonance method on samples 28 days old. The aim was to check the possibilities of using the recycled tires in construction as reinforcement to the gypsum binder. Many published papers deals with composite materials based on gypsum, but mainly with standard non-metallic reinforcement such as glass fibers, PP and PE fibers etc.

Reduction of bromate from water by zero-valent iron immobilized on functional polypropylene fiber

The highly reactive micro-sized zero-valent iron (mZVI) immobilized in acrylic acid (AA) functionalized polypropylene fiber (PP-g-AA) was successfully prepared, and used for the bromate removal from solution. The PP-g-AA was used as a novel carrier for its high strength and continuous supports with chelating functional groups. The mZVI was immobilized firmly on PP-g-AA via complexation and liquid phase reduction, which prevented the aggregation of mZVI and release of Fe ions. The mZVI/PP-g-AA was characterized by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and emission scanning electron microscope (SEM) and Brunauer–Emmett–Teller (BET) surface area analyzer. Due to the coordination with carboxyl groups, the mZVI presented excellent distribution and high activity for reduction of bromate. Meanwhile, the bromate removal efficiency affected by initial bromate concentration, pH, common anions and humic acid (HA) were respectively evaluated. The effects of pH value on bromate reduction was slight. It was related to the buffering performance of the COOH/COO− groups around the areas where the reduction took place. The inhibitory effects of common anions and HA were slight and negligible. In this study, the concentration of Fe2+/3+ in solution was low (<19.0μg/L) and kept constant during reduction process. On account of the coordination of carboxyl groups on the functional PP fibers, Fe2+/3+ could be remained in the carrier and not be released into solution.

A study on the tensile properties of silicone rubber/polypropylene fibers/silica hybrid nanocomposites

Metacarpophalangeal joint implants have been usually made of silicone rubber. In the current study, silica nano particles and polypropylene fibers were added to silicone rubber to improve silicone properties. The effect of the addition of silica nano particles and polypropylene fibers on the tensile behavior of the resultant composites were investigated. Composite samples with different content of PP fibers and Silica nano particles (i. e. 0, 1 and 2wt%) as well as the hybrid composite of silicone rubber with 1wt% SiO2 and 1wt% PP fiber were prepared. Tensile tests were done at constant cross head speed. To study the body fluid effect on the mechanical properties of silicone rubber composites, samples soaked in simulated body fluid (SBF) at 37°C were also tested. The morphology of the samples were studied by scanning electron microscope. Results of analysis revealed that an increase in PP fibers and silica nano particles content to 2wt%, increases the tensile strength of silicone rubber of about 75% and 42% respectively. It was found out that the strength of the samples decreases after being soaked in simulated body fluid, though composites with PP fibers as the reinforcement showed less property degradation.

PAHs in Household Floor Dust Collected in Amman, Jordan

PP-g-MAA oil sorption materials were synthesized by graft polymerization method of methacrylic acid (MAA) onto polypropylene fibers (PP) using divilylbenzene (DVB) as cross-linking agent. The virgin and grafted PP fibers were characterized by FT-IR, SEM, TGA, and DSC analysis. The results revealed that MAA was grafted onto PP fibers successfully. Factors affected the grafting yield (GY) were examined such as monomer concentration, initiator concentration, effects of temperature as well as reaction time. At the DVB and MAA concentrations of 1.5% and 2%, respectively, the maximum GY was obtained (73.1%). The obtained correlation coefficient (R2) from well-known Langmuir sorption isotherms suggested well-fitting of the experimental data, which is assumed that at maximum coverage with identical sorption sites, there is monomolecular layer sorption on the PP-g-MAA surface. Oil sorption capacity of PP-g-MAA fibers was investigated which revealed a maximum oil sorption capacity (qmax) of 20.833 g/g. SEM pictures and FTIR results were taken for these materials under test.

Fire Spalling Prevention via Polypropylene Fibres: A Meso- and Macroscale Approach

A deep understanding of concrete at the mesoscale level is essential for a better comprehension of several concrete phenomena, such as creep, damage, and spalling. The latter one specifically corresponds to the separation of pieces of concrete from the surface of a structural element when it is exposed to high and rapidly rising temperatures; for this phenomenon a mesoscopic approach is fundamental since aggregates performance and their thermal properties play a crucial role. To reduce the risk of spalling of a concrete material under fire condition, the inclusion of a low dosage of polypropylene fibres in the mix design of concrete is largely recognized. PP fibres in fact evaporate above certain temperatures, thus increasing the porosity and reducing the internal pressure in the material by an increase of the voids connectivity in the cement paste. In this work, the contribution of polypropylene fibres on concrete behaviour, if subjected to elevated thermal ranges, has been numerically investigated thanks to a coupled hygrothermomechanical finite element formulation. Numerical analyses at the macro- and mesoscale levels have been performed.

Investigation on Flexural Properties of Hybrid Fibre Reinforced Self-compacting Concrete

The paper considers compressive and flexural parameters of self-compacting concrete reinforced with combination of steel and polypropylene fibers. Three volume ratios of steel fibers (0.5%, 1.0%, 1.5%) were mixed with two amounts (0.3%, 0.9%) of two types of polypropylene fibers. The influence of hybrid fibers on the compressive strength of SCC was negligible and comprised in the range of -5 to 11% of the strength of the matrix. Based on the flexural tensile tests on hybrid fibre-reinforced mixes it was noticed that steel fibers play the most important role in enhancement of the mechanical parameters. Meanwhile, in the hybrid mix of polypropylene fibers only slightly improve the toughness, irrespectively of the length of the PP fibers. The highest applied amount of the longest polypropylene fibers indeed improved the flexural parameters of the SCC matrix reinforced with steel fibers but on the other hand such concrete did not satisfy the requirements for SCC in the fresh state.

Influence of Fibers Geometry on the Intake Height PP Yarns

Fibrous materials represent an important product in the application of fibres destined for clothing production, indoor textiles production and technical textiles production. Different kinds of clothing are used in direct or indirect contact with human skin. These types of textiles require appropriate utility properties, mainly suitable heat and moisture transport - physiological properties. This work examines the effect of the geometry of PP fibres on the structure and utility properties of textiles – thermoclothing. The fibers geometry highly influences the heat and mass transfer through textile clothing. Four polypropylene fibers of different cross sectional shapes namely four channel profile, round hollow, round and hollow triangle were used in this work. A relationship between the called shape factors for the different fibers was established. The intake heights were analyzed. It was found that the size of the surface area has an impact on process of processing fibres, determines the penetration of gases or liquids, sorption and diffusion in the fibres. The cross sectional shape of fibers has also influences the heat and mass transfer through textile clothing.

The effect of nano-titanium dioxide on the self-cleaning properties of TiO2-PP composite fibers

This study aims to synthesis the self-cleaning fibers. The nano-titanium dioxide (<TEX>$TiO_2$</TEX>) were blend with the polypropylene (grade 561R) at 1wt%, 3wt%, 5wt%, 10wt%, 15wt% and 20wt%. The <TEX>$TiO_2$</TEX>-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 <TEX>$nTiO_2$</TEX>-PP fibers decreased with increasing of the amount of <TEX>$TiO_2$</TEX>. The presents of the <TEX>$TiO_2$</TEX> in the PP fibers significantly showed the improving of the self-cleaning properties under sunlight and 20 watt of UV radiation. The <TEX>$TiO_2$</TEX>-PP fibers in presents of <TEX>$TiO_2$</TEX> 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.

원형패널 시험을 활용한 두 종류 섬유 보강 숏크리트의 휨거동 평가

This study evaluated the flexural performance of steel and PP fiber reinfroced shotcrete using round panel test according to ASTM that can consider the actual stress of fiber reinforced shotcrete in tunnel and under ground structures. The results of round panel test are converted to the square panel test results according to the EFNARC. The energy absorptions of each fiber reinforced shotcrete were classified according to the EFNARC toughness classification. Test results show that the PP fiber reinforced shotcrete has better flexural performance compared with the steel fiber reinforced shotcrete.

Syndiotactic polypropylene nanofibers obtained from solution electrospinning process at ambient temperature

ABSTRACTFabrication of semicrystalline syndiotactic polypropylene (sPP) nanofibers by solution electrospinning was studied. It was found that sPP nanofibers with an average diameter of 230 nm were successfully fabricated via solution electrospinning with methylcyclohexane as solvent at room temperature (25°C). The obtained diameter was significantly thinner than the minimum diameter of 350 nm of PP fibers that were reported previously. It was also found that increasing viscosity of the sPP solution, which was customarily a useful way of fabricating noncrystalline thin fibers, was found ineffectual in producing thinner semicrystalline sPP fibers in our experiments. In fact, a careful selection of solvent by considering the evaporation rate and the specific viscosity could effectively lead to the fabrication of thinner sPP fibers by imposing proper elongation and preventing the sPP solution from gelation. The results could be applied to other semicrystalline polyolefins with similar gelation characteristics analogous to sPP to produce thinner nanofibers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43238.

Analysing effect of the factors on ultrasonic seam tensile properties of nonwoven fabrics by Nested Anova Design

Purpose– The purpose of this paper is to investigate the factors effecting ultrasonic seam tensile properties.Design/methodology/approach– In this study, 100 percent polypropylene and 100 percent polyester spunbond and meltblown nonwoven fabrics were sewn by using ultrasonic sewing machine with different rollers which have two, three and four rows. Seam tensile properties of the sewn nonwoven fabrics were investigated. Four-Level Nested Anova Design was applied to the data by using Minitab 15 software program.Findings– Higher seam strength values were obtained by using four rows roller, PP fiber, spunbond fabric and 50 g/m2 fabric area density for all nonwoven fabrics. Statistical significance was found between fabric area density, roller rows and seam tensile strength properties and between fabric type, roller rows and seam elongation at break values.Originality/value– When the authors look at the studies related to ultrasonic sewing, several researchers studied on welding parameters of ultrasonic sewing but very limited studies were performed on assembling of nonwoven fabrics with ultrasonic sewing. Therefore effect of production methods of nonwoven fabrics on the properties of ultrasonic sewing such as seam strength and elongation at break should be investigated.

Strength and deformation characteristics of engineered cementitious composite slabs with different polymer fibres

This paper presents a study on the compressive and flexural strength of engineered cementitious composite (ECC) cubes and slabs, reinforced with various polymer fibres. The type of fibre, fibre content and aspect ratio were the parameters considered in this study. For all types of fibre, the compressive strength of the ECC decreased as the reinforcing index increased. For the ECC polypropylene fibre (PP) slabs, the first crack strength significantly decreased with an increase in the fibre content. For the ECC polyethylene fibre (PE) slabs, the first crack strength decreased as the reinforcing index increased. For the ECC PE slabs, the usage of PE 1600D fibres showed a substantial increase in flexural strength due to their higher tensile strength and E modulus. The ECC PP slabs behaved like plane concrete due to the zero value of flexural strength, which was attributed to the weak interfacial bonding with the cement matrix, low tensile strength and E modulus of the PP fibres. The highest ductility was observed for the ECC-PE slabs with the highest recorded deflection values; these values achieved many extended multiple cracks and an extensive area under the load–deflection curve indicating high energy absorption capacity.

Preparation and characterization of polypropylene fiber-grafted polybutylmethacrylate as oil sorbent

Polypropylene fiber-grafted polybutylmethacrylate (PP-g-PBMA), a new oil absorbent, was prepared by suspension polymerization using butyl methacrylate as monomer, benzoyl peroxide (BPO) as initiator, and N,N′-methylenebisacrylamide as cross-linker. The effects of monomer concentration, initiator concentration, and cross-linker dosage on the oil absorbency were studied. The results revealed that the pseudo-second-order kinetics model fitted well with the experimental results. The sorption isotherms studies indicated that the equilibrium process was well described by the Freundlich isotherm model. The structures of polypropylene fiber (PP) and PP-g-PBMA were characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), N2 adsorption–desorption, contact-angle (CA) measurements, and differential thermogravimetric analysis. The results of FTIR and SEM show that PBMA was successfully grafted onto PP fiber substrate. The maximum oil sorption capacity of PP-g-PBMA for toluene, diesel, soybean oil, and lubricating oil can reach 18.65, 25.74, 33.56, and 38.90 g/g, respectively. In order to simulate real marine environment, the oil sorption capacities of PP-g-PBMA at different stirring speed values, temperatures, and salinity were investigated. Furthermore, PP-g-PBMA can be reused and recycled more than eight times. It can be concluded that PP-g-PBMA with low-cost and high oil sorption capacity could be used for removal of oil spill.