Properties Of Polypropylene Fibers Research Articles

Comparison of Colour Properties of Polypropylene and Poly-(Lactic) Acid Fibres Dyed With Photoluminescent Dye

Abstract Every manufacturer wants to protect their textile products and their brand. A possible solution is, for example, the insertion of fibres with special pigments visible under irradiation by UV light into the final product. The paper focused on the study of the structure and colourimetric properties of polypropylene (PP) and poly-(lactic) acid (PLA) fibres modified with photoluminescent dye and halloysite (HNT) modified with photoluminescent dye. The photoluminescent dye and HNT modified with photoluminescent dye affected the structure of PP and PLA fibres differently. Increasing the HNT content up to 0.15 % increased the orientation of the PP fibres. In the case of PLA fibres, the increased content of photoluminescent dye in PLA fibres increased their orientation in the observed concentration area. PLA-based knitted fabrics showed better light stability, where there was no visible degradation of the knitted fabric, only its darkening. Likewise, PLA-based knitted fabric showed luminescence in UV light even after accelerated light aging.

Dual role of nanoclay in the improvement of the in-situ nanofibrillar morphology in polypropylene/polybutylene terephthalate nanocomposites

The present study has addressed the effects of nanoclay on the properties of polypropylene (PP)/polybutylene terephthalate (PBT) blend fibers such as their dyeability and, rheological and resiliency behaviors which are produced by melt spinning. The results of the differential scanning calorimetry (DSC) analysis indicated that the presence of both nanoclay and PBT significantly influenced the crystallinity of PP which also confirmed their nucleating effects on the nanocomposite fibers. Compared to neat PP fibers, the incorporation of 0.5–1wt.% of nanoclay and 10 wt.% of PBT nanocomposite fibers caused approximately 23% and 52% enhancements in the resiliency and dye uptake respectively without using toxic carriers. The rheological analysis was carried out for investigating the viscoelastic behavior, and microstructural and dispersion of nanoclay in the nanocomposite fibers. The rheological behavior in the small amplitude oscillatory shear (SAOS) test demonstrated the percolation threshold network of the structure of PBT fibrils in the PP matrix. When the PBT domains are fibrillated, the storage modulus (G′) and complex viscosity increase compared to neat PP. Also, the nonterminal behavior at low frequencies indicates the uniform dispersion of nanoclay in fiber nanocomposites. These all cause the improvement of the melt strength of the PP matrix. Transmission electron microscopy (TEM) was used to study the dispersion and localization of nanoclay. Nanoclay has also played a compatibilizing role in the immisible PP/PBT blend and was localized mainly in the PBT disperse and interface, and therefore prevented coalescence. The role of the compatibility of nanoparticles is to decrease the mean diameter of the nano-fibrils to 75 nm, for the hot-drawn nanocomposite fibers, as measured by scanning electron microscopy (SEM). All of the above lead to increasing the melt strength and elasticity of the nanocomposites in the fiber spinning process.

Polypropylene fiber reinforced concrete improved by using silica fume and acrylic emulsion polymer

The current study aims at exploring the beneficial effect of silica fume (SF) and acrylic emulsion polymer (PR) on the enhanced properties of polypropylene fiber reinforced concrete (FRC) with the supplementary cementitious binder comprised of the Portland cement, slag, silica fume and fly ash. The compressive strength and impact-abrasion resistance were used for the estimation of engineering properties while the water absorption performance, surface electricity resistance, and rapid chloride penetration resistance were used for estimation of durability. Experimental results showed that a sole addition of SF increased the compressive strengths but decreased the abrasion-impact resistances of modified FRCs, which was just opposite to the influence of a sole addition of PR. A sole addition of either the SF or PR could moderately improve the durability of modified FRCs, respectively. However, due to the beneficial effect of the complementary interaction between SF and the optimal amount of PR, the mechanical properties and durability of modified FRCs seemed to become significantly improved.

Influence of steel and PP fibers on mechanical and microstructural properties of fly ash-GGBFS based geopolymer composites

In this study, experimental investigations were carried out to estimate the mechanical and microstructural properties of polypropylene (PP) and steel fiber reinforced geopolymer mortar. Two industrial by-products are used as binders to produce the geopolymer composites, i.e., fly ash (FA) and ground granulated blast furnace slag (GGBFS). Different percentages of PP and steel fibers are used in geopolymer mortars to find the mechanical properties such as compressive, splitting tensile and flexural strengths were investigated to understand the strength behavior. However, the compressive elastic modulus values were estimated through the proposed equation based on the compressive strength of the fiber reinforced geopolymer composite samples. Moreover, to understand the geopolymeic reaction, microstructural studies, i.e., scanning electron microscopy (SEM), were conducted. The experimental results revealed that the addition of PP fibers up to 2.0% (volume fraction) enhanced the flexural properties of geopolymer mortar samples. The compressive strength of the steel fiber-reinforced geopolymer composite reached a maximum of 2.5% volume fraction, being a 13.26% improvement over the control mix. The flexural toughness index of the PP and steel fiber reinforced composites improved with increasing the fraction. However, steel fiber reinforced geopolymer samples are shown better flexural toughness compared to PP fibers. The SEM analysis of the geopolymer control mix achieved a good degree of geopolymerization and both the fibers yielded a considerable interfacial bonding with the geopolymer paste.

Mechanical Properties of Polypropylene Fiber

Mechanical Properties of Polypropylene Fiber

Effect of Organoclay on the Rheology, Morphology, Thermal and Mechanical Properties of Nanocomposite Fibers Based on Polypropylene/Poly(Trimethylene Terephthalate)/Organoclay

Modification of the rheological and thermal properties of polypropylene (PP) was accomplished through the in-situ generation of PP/poly(trimethylene terephthalate) (PTT) nanocomposites fibrils containing organoclay via a melt spinning process. The development of the fibrillar structures in the fibers during the melt spinning and a subsequent hot drawing process was confirmed by scanning electron microscopy; the lowest mean diameter of the nano-fibrils was 74 nm for the hot drawn nanocomposite fibers consisting of 10 wt.% of PTT and 1 wt.% organoclay in the PP. The results of wide-angle X-ray diffraction and differential scanning calorimetry indicated that the presence of the 10 wt.% of PTT and 1 wt.% organoclay in the nanocomposite fibers led to an approximately 16% increase in the crystallinity of the PP, compared to pure PP fibers. The distribution of the organoclay in the nanocomposites was investigated using transmission electron microscopy and small-angle X-ray scattering.

Surface Hydrophilic Modification of Polypropylene Fibers and Their Application in Fiber-Reinforced Cement-Based Materials

Among the various polymer fibers available, polypropylene (PP) fibers are often used to improve the impermeability, impact resistance, anti-wear and crack resistance of concrete. In order to improve the interfacial adhesion between PP fibers and cement a series of PP composite fibers were prepared by melt spinning with micro-silica (MSi) as a hydrophilic modifier and the structure and properties of the composite fibers were studied. The results showed that the composite fibers displayed rougher and more hydrophilic surfaces than the pure PP fibers. As revealed by single fiber pull-out tests, the interfacial adhesive strength between the PP fibers and a cement matrix increased obviously after adding the MSi to the PP fibers. The flexural strength and compressive strength of the cement mortar blended with the composite fibers were much better than those of the cement modified by pure PP fibers. The cement mortar enhanced by the composite fibers containing 10 wt.% of MSi showed the best mechanical strength, which we suggest was caused by a balance between fiber strength and interfacial adhesive strength. In general, our research indicated that the mechanical properties of PP fiber reinforced cement-based materials could be further enhanced by mixing appropriate amounts of MSi in the PP fibers which provides a novel strategy to design high-ρperformance materials for modern architecture.

Relationship between microstructure and performance of polypropylene fibre reinforced cement composites subjected to elevated temperature

This article presents the investigation on mechanical and transport properties of polypropylene (PP) fibre reinforced cement composites with varying fibre volume (0.05–0.30%). Fresh property of the fibre reinforced concrete was evaluated through the flow table test, while hardened properties including compressive strength (1, 3, 7 and 28-day), and modified flexural strength, ultrasonic pulse velocity and water absorption were assessed at the 28-day. The effects of fibre addition on mechanical properties were evaluated at room temperature and 200 °C. Microstructural characterizations were performed using field emission scanning electron microscopy (FESEM) coupled with energy dispersive X-ray spectroscopy (EDX). Micrographs of the failed PP fibre reinforced composites indicated that the increase in flexural strength at room temperature was attributed to the crack bridging and fibre debonding at the fibre/matrix interface. Higher water absorption value was achieved for PP reinforced composites subjected to elevated temperature compared to control mortar. FESEM/EDX analyses on the elevated temperature samples indicated that the increment was due to the growing of macro-pores from the empty space left behind by fibre settlement. In conclusion, the addition of PP fibres in the cement mortar adversely affect the strength when the composite is subjected to elevated temperature, but resulted in improved durability.

Preparation, mechanical and electric properties of polypropylene fiber reinforced lead zirconate titanate flexible materials

The preparation and properties of polypropylene fiber (PPF) reinforced lead zirconate titanate (PZT) flexible materials were investigated in this paper. PPF reinforced PZT composites were prepared by hot pressing. The microstructure, mechanical and electrical properties of PPF reinforced PZT composited were tested by Scanning Electron Microscope (SEM) technology, Universal tester, d33 quasi-static tester and LCR tester and were systematically characterized. The results showed that with the increase of PPF volume fraction, the reticular structures in the composites increase, and the bending strength σc and tensile strength σb of the composites increase; meanwhile, the relative dielectric constant εr and dielectric loss tanδ of the composites decreased gradually, but the piezoelectric strain constant d33 of the composite increases first and then decreases with the increase of PPF volume fraction. When the PPF volume fraction is 50%, the composite has superior mechanical properties and comprehensive electrical properties, and is relatively in mechanical electrical equilibrium with σc is 25.402 MPa, σb is 7.049 MPa, εr is 77.216 and d33 is 15 pC N−1.

The crystallization of polypropylene/halloysite fibers

The halloysite (HNT) in the form of nanotubes was used as an agent for the improved mechanical, thermo-mechanical as well as surface properties of polypropylene (PP) fibers. The halloysite is the nanoadditive that can affect differently the crystallization of PP in the non-oriented and oriented systems. The structure and mechanical properties of PP and PP/HNT fibers depended on the crystallinity and crystallization kinetics of PP at the fiber preparation. The Avrami method on the determination of isothermal crystallization kinetics parameters as well as an estimation of melting and crystallization temperatures and melting and crystallization enthalpies was used for the study of thermal behavior of polypropylene/halloysite non-oriented and oriented blends and fibers. Morphological structure, mechanical and thermo-mechanical properties of polypropylene/halloysite fibers were observed. An influence on all assessed properties was evaluated from the point of halloysite content in the PP and/or PP fibers. The increased HNT content in the non-oriented PP/HNT blends at the isothermal crystallization increases the rate crystallization (decreased t1/2 and free energy σe, increased K) of PP in comparison with the pure PP. The crystallinity of PP in the oriented PP/HNT fibers is not primarily affected by addition of the HNT content 3 mass% and does not change their mechanical and thermo-mechanical properties. 5 mass% HNT increases the crystallinity of PP in PP/HNT fibers expressing mainly the decrease in tenacity at the break, Young’s modulus and shrinkage.

Struktura in lastnosti s fotoluminiscentnim pigmentom modificiranih polipropilenskih vlaken, namenjenih varovanju originalnosti izdelkov

Struktura in lastnosti s fotoluminiscentnim pigmentom modificiranih polipropilenskih vlaken, namenjenih varovanju originalnosti izdelkov

The influence of elevated temperatures on the mechanical properties of polypropylene fiber reinforced concrete

This paper describes the strength of Polypropylene Fiber Reinforced Concrete (PFRC) exposed to the elevated temperatures. In the study, control specimens without any fibers and the concrete specimens with the ratios of 0.30, 0.60, 0.90 and 1.20 kg/m³ polypropylene fibers both in woolen and bar shape fiber have been produced. The specimens have been kept in the laboratory conditions for 28 days. Shortly after the curing period was completed, every group was heated at 23, 150, 300, 450, 600 and 750°C for two hours then the compressive strengths of them were determined. The maximum compressive strength was obtained by the specimens including 0.30 kg/m³ woolen polypropylene. For this group, the compressive strength increase was 8% according to the control specimens. The compressive strengths of bar polypropylene fiber concrete were higher than the wool fibers under elevated temperatures. On the other hand, more compressive strength values are obtained from the control specimens than fiber groups at 600°C temperature. Melting the polypropylene fiber at 500°C formed some pore spaces in concrete and caused reduction of the compressive strength.

Fiber-spun polypropylene/polyethylene terephthalate microfibrillar composites with enhanced tensile and rheological properties and foaming ability

Modification of the mechanical and rheological properties of polypropylene (PP) is accomplished through the in-situ generation of polyethylene terephthalate (PET) fibrils via fiber spinning of PP/PET (95/5 wt%). This modification increases the tensile strength of PP fibers by up to 46% and elongation at break by up to seven-folds. The change in the tensile properties is governed by the draw ratio. Uniaxial extensional viscosity measurements show a strain-hardening behavior in the fiber-spun PP/PET, not observed in the neat PP or in the melt-blended PP/PET. The oscillatory shear behavior in the linear viscoelastic region is studied to understand the percolation properties of PET fibrils in PP. When the PET domains are fibrillated, the storage (G′) and loss (G″) moduli increase and their slopes decrease at low frequencies compared to neat PP or melt-blended PP/PET, indicating that the fibril network responds elastically over long timescales. The wide-angle X-ray scattering (WAXS) data shows the presence of γ-polymorph crystals of PP in both PP and the fiber-spun PP/PET. Foam extrusion is used as a model polymer process to study the effect of the PET fibrils on the processability of PP. Results reveal that the presence of PET fibrils in PP yields foams that exhibit up to two orders of magnitude higher cell densities and up to a five-fold increase in the expansion ratio relative to the neat PP. Enhancing the foaming ability of polymer blends by fibrillating the dispersed phase using fiber spinning is technologically promising.

Adaptive spatial carrier frequency method for fast monitoring optical properties of fibres

We present an extension of the adaptive spatial carrier frequency method which is proposed for fast measuring optical properties of fibrous materials. The method can be considered as a two complementary steps. In the first step, the support of the adaptive filter shall be defined. In the second step, the angle between the sample under test and the interference fringe system generated by the utilized interferometer has to be determined. Thus, the support of the optical filter associated with the implementation of the adaptive spatial carrier frequency method is accordingly rotated. This method is experimentally verified by measuring optical properties of polypropylene (PP) fibre with the help of a Mach–Zehnder interferometer. The results show that errors resulting from rotating the fibre with respect to the interference fringes of the interferometer are reduced compared with the traditional band pass filter method. This conclusion was driven by comparing results of the mean refractive index of drown PP fibre at parallel polarization direction obtained from the new and adaptive spatial carrier frequency method.

Properties of polypropylene fibers using the green chemical orotic acid as nucleating agent

It has been reported in the technical literature that orotic acid can be used in order to induce improved crystallization of biodegradable and biocompatible polymers like poly(L-lactic acid), polyhydroxybutyrate and poly(hydroxybutyrate-co-hydroxyhexaonat). The expected advantage of the changed crystalline structure is a reinforcing effect of the polymers. A lot of papers reported about the application of inorganic and organic agents for acceleration of heterogeneous nucleation. This study reports on an attempt to use orotic acid as appropriate non-toxic nucleating agent for improving mechanical properties of isotactic polypropylene. Special attention is given to demonstrate the effect of nucleation in a typical melt spinning process in order to improve the mechanical properties. The effects were demonstrated using rheology, thermal analysis and tensile testing.

Effect of Addition of Multiwalled Carbon Nanotubes on the Piezoelectric Properties of Polypropylene Filaments.

The effect of addition of multiwalled carbon nanotubes (CNTs) on the piezoelectric properties of polypropylene (PP) monofilaments has been investigated. Various amounts of CNTs (0%, 0.01%, 0.1% and 1% weight ratios) were melt-blended with PP and the resulting nanocomposites were extruded in a continuous process with simultaneous on-line poling to produce monofilaments. Concurrent stretching at a draw ratio of 5:1 and polarisation at applied electric fields of 15 kV of PP/CNT filaments was observed to enhance the piezoelectric properties. The microstructure and crystallinity of the filaments was analysed using scanning electron microscopy (SEM), differential scanning calorimetric (DSC) and Fourier transform infrared spectroscopy (FTIR) techniques. Voltage generation by the CNT-modified PP filaments was determined by the application of predetermined load impact. The results show that the incorporation of CNTs in the PP fibre structure has a considerable impact on the enhancement of piezoelectric properties of the PP filament obtained that the peak voltage generation was almost four fold (from 0.76 V to 2.92 V) when 0.1 wt% of CNTs added into the polymer. This is owing to the fact that carbon nanotubes act as nucleating agent for enhancing the crystallisation during the melt extrusion process.

Influence of Quaternary Ammonium Salts on Absorption Properties of Polypropylene Fiber

The most effective method for coloring polypropylene fiber with dispersed dyes was determined by studying the effect of quaternary ammonium salts on their absorption properties.

Effect of fibre inclusion on dynamic properties of clay

One of the causes of heavy damage due to earthquake motions is the role of soft clay in amplifying bedrock ground motions. Improving the soil conditions using polypropylene fibres at a site in order to mitigate earthquake damage could be one of the methods to modify site conditions. In this study, the optimum fibre contents were obtained for mixtures of clay with two different types of fibre. Then the dynamic properties of polypropylene fibre reinforced clay with different fibre contents were determined using resonant column testing. The study showed that the inclusion of fibre at optimum fibre content can improve the dynamic properties of clay at the low shear strains used. Test results indicated that both the shear modulus and damping increased. Hence, the inclusion of fibre in clay can provide a double benefit for the dynamic response of a site by increasing the stiffness of the site and reducing its amplitude of vibration.

Bond Characteristics of Macro Polypropylene Fiber in Cementitious Composites Containing Nanosilica and Styrene Butadiene Latex Polymer

This study evaluated the bond properties of polypropylene (PP) fiber in plain cementitious composites (PCCs) and styrene butadiene latex polymer cementitious composites (LCCs) at different nanosilica contents. The bond tests were evaluated according to JCI SF-8, in which the contents of nanosilica in the cement were 0, 2, 4, 6, 8, and 10 wt%, based on cement weight. The addition of nanosilica significantly affected the bond properties between macro PP fiber and cementitious composites. For PCCs, the addition of 0–2 wt% nanosilica enhanced bond strength and interface toughness, whereas the addition of 4 wt% or more reduced bond strength and interface toughness. The bond strength and interfacial toughness of LCCs also increased with the addition of up to 6% nanosilica. The analysis of the relative bond strength showed that the addition of nanosilica affects the bond properties of both PCC and LCC. This result was confirmed via microstructural analysis of the macro PP fiber surface after the bond tests, which revealed an increase in scratches due to frictional forces and fiber tearing.

Influence of the Concentration and Shape of Carbon Fillers on the Mechanical Properties of Polypropylene Fibers

Polypropylene fibers containing various concentrations of spherical (technical carbon) and anisotropic (nanofibers, nanotubes) carbon nanoparticles were prepared under laboratory conditions. The mechanical properties of the composite fibers were determined. It was shown that their strength and elasticity modulus increased by ~1.5 times only upon adding small concentrations (1-5 mass%) of anisotropic particles. Adding technical carbon at all concentrations decreased the fiber strength and fracture bending with an insignificant increase of elasticity modulus. The development of nanocomposites based on polymeric matrices is a promising area of contemporary materials science. Electrically conductive additives such as soot, graphite, chopped fibers, and metal powders are used to decrease charging during processing of synthetic materials and use of items made of them. However, synthetic composites with stable anti-static properties can be produced only by adding large concentrations (10-20 mass%) of these fillers [1-3]. It is worth noting that filled samples are weaker than the starting polymer. Fillers with particle sizes from several nanometers to tens of nanometers, i.e., carbon nanofibers and nanotubes, are beginning to play an increasingly important role. Such fillers can produce polymer composites with controlled mechanical, electrical, and other transport properties. It was shown [4] that the threshold concentrations of electrically conductive fillers that were required for stable anti-static protection of the polymer matrix could be reduced considerably from 15 mass% for technical carbon (TC) to 0.5 mass% for nanotubes by increasing the axial ratio of the nanoparticles. It was also demonstrated [5-7] that the mechanical properties of nanocomposites with anisotropic nanoparticles could be increased by preliminary orientation of carbon nanofibers (CNF) along the fiber axis during spinning of the composite from the melt. The literature on the strength of composites containing carbon nanotubes (CNT) and CNF [8-12] indicates that the strength of nanocomposites can be increased only with small (<5 mass%) additions of nanofillers. Increasing the concentration further does not affect the strength or even lowers it. The elasticity modulus of such materials can be increased by ~1.5 times with the same low nanoparticle concentrations and then almost does not change. As a rule, blocks or films were investigated in many publications focused on the physical-mechanical properties of nanocomposites with anisotropic nanoparticles [5, 6, 13-15]. Nevertheless, industrial manufacturing of polymers used to fabricate textiles is often accompanied by additional oriented drawing at elevated temperatures [16, 17]. This can improve the mechanical and operating properties of the final products. The influence of the type, shape, and concentration of dispersed nanoparticles on the bending and tensile properties of a single polymeric matrix subjected to oriented drawing is practically unstudied.