Properties Of Polypropylene Fibers Research Articles

Study of the wettability properties of polypropylene nonwoven mats by low‐pressure oxygen plasma treatment

AbstractSurface modification by plasma treatment is widely used for textiles and polymeric materials. Plasma processes are environmentally friendly and reduce chemicals and energy consumption. This study reports the effect of cold, low‐pressure oxygen plasma on the wettability properties of polypropylene (PP) nonwoven mats. The wetting properties were examined using contact angle, surface energy, and diameters of the drop after 20 s of treatment. It was found that plasma treatment had a significant effect on the wettability of PP fibers. The ageing for 90 days had no significant effect on the wettability. It was also shown that the morphology of the fibers was not affected by the plasma treatment. Copyright © 2007 John Wiley & Sons, Ltd.

Modification and properties of polypropylene fibers using aluminosiloxane

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.

Formalization of the Problem of Optimum Control of the Mechanical Properties of Polypropylene Fibre

The problem was examined and a system was proposed for optimization of industrial fabrication of chemical fibres using relaxation parameters as indirect evaluation of the structure of the polymer. The necessity of modeling and optimizing the process in a mathematical model is demonstrated, and the stages of the work that solves the optimization problem are noted.

Fibre-forming blends of polypropylene and polyethylene terephthalate

Bicomponent fibres represent of the new ways for the preparation of synthetic fibres with more variable properties. The polypropylene (PP)-poly(ethylene terephthalate) (PET) fibre-forming blend is very interesting because of the improvement of dyeability from bath and some mechanical properties of PP fibres. The new polymer additives containing ester groups which can be added as masterbatches during melting and extrusion processes have been developed in the last years. It has been found that rheological properties of the basic polymer (PP) and polymer additives have a significant role in the blend formation and in spinning. In this work, the influence of some non-reactive low-molecular compounds on the processing of fibre-forming PP-PET blends and on the properties of blend fibres are presented.

Structure and properties of polypropylene fibers during thermal bonding

The role of fiber morphology in a thermal point-bonding operation was investigated. Polypropylene fibers were spun to produce fibers with a wide range of structure, keeping the diameter same. The fibers were characterized for their structure and properties before and after bonding by differential scanning calorimeter (DSC), thermo-mechanical analysis (TMA), birefringence measurement and tensile testing. The results show that the fiber samples with different morphology vary in their bonding behavior, which in turn determine the fabric properties. Significant changes were observed in fiber structure during thermal bonding. The extent of change taking place during the process was dependent on the initial morphology of the fibers.

Optimization of the Electret State of Polymer Fibres

The effect of the electrification parameters and industrial pneumatic extrusion spinning on the electret properties of polypropylene fibres. In a strong enough corona discharge field, many factors can cause the formation of an electret, manifested as both injection and dipole polarization. Increasing the intensity of the process and polarization conditions and repeated processing of the material can potentiate the charge state of the fibres.

Elastic Modulus of Fibers Spun from the Binary Polymer Blends

Among mechanical properties of polypropylene fibers, spun from the blend of medium molecular weight CR-polymer with added high molecular weight polymer in the composition range of. 10-50 wt%, special interest is focused on the elastic modulus in this paper. In the case of two-phase composite system, the resultant modulus is a function of the moduli of the individual pure components, the volume of the weight fraction, the geometry and packing of the disperse phase and the Poisson ratio of the matrix. In present paper only several representative equations for the calculation of elastic properties of a two-phase systems are presented. This present work is concerned with applicability of those theories to the specific case, drawn polypropylene fibers spun from blend of different polymer grades. Predicted elastic modulus calculated from the Kleiner's simplex equation is compared with the elastic modulus of drawn fibers determined from the stress vs. strain curve.

Mechanical properties of polypropylene fibers produced from the binary polymer blends of different molecular weights

Mechanical properties of polypropylene fibers produced from the binary polymer blends of different molecular weights

Mechanical properties of polypropylene/polyamide 6 blends: Effect of manufacturing processes and compatibilization

AbstractThe properties of polypropylene (PP)/polyamide 6 (PA) blends, obtained by the following two different blending methods, were investigated. Blends of PP/PA and PP/PA/maleic anhydride have been prepared using a twin screw extruder and a fiber cutting, flying and mixing apparatus that directly commingles PP fiber and PA fiber. The properties measured include rheological properties by means of a capillary rheometer, morphologies by scanning electron microscopy, and mechanical properties by a universal testing machine and a high rate impact tester. In the presence of compatibilizer, a marked dispersibility of the polymer blends of PP and PA was observed, and mechanical properties were found to increase as a result of improvement of the interfacial adhesion and the dispersibility. The properties of PP/PA blends manufactured by two different pieces of equipment were shown to be similar in the case of melting both resins. But in particular, superior impact properties were obtained in blends not melting PA fibers as a dispersed phase rather than blends using maleic anhydride grafted polypropylene (PP‐g‐MA) as a compatibilizer.

Structure–property relationship of modified polypropylene–polycaproamide fiber

AbstractThe effect of the addition of polyamide on the structure and properties of polypropylene fiber has been studied. Although a good fiber is obtained with a composition containing only a very low concentration of polycaproamide in polypropylene, the increase in polyamide content decreases the drawing strength of the mixed polymer melt due to sudden lowering of melt viscosity and strength. The poor melt strength of the studied polymer mixture is attributed to increased heterogeneity induced in the system with increased concentration of polyamide. Use of an effective interphase modifier, maleic anhydride‐grafted polypropylene, however, was found to improve fiber properties of the studied polymer mixtures even with a very high concentration of polyamide as the dispersed phase. Thus, addition of a 1–4 wt % interphase modifier facilitates the formation of good fiber even with 30 wt % polycaproamide in the blend. This improvement is attributed to the improved dispersity of polyamide in the polypropylene matrix as well as improved phase compatibility due to the formation of a chemically modified polyamide during melt extrusion in the presence of maleic anhydride‐grafted polypropylene.

Effect of high molecular weight polyethylene oxide on the structure and properties of polypropylene fibres

The effect of microamounts of PEO with M = 4 × 10 6 and 5 × 10 6 on the structural features and properties of PP fibres has been studied. On addition of 0·15−0·2% PEO slight rise in fluidity is observed linked with increase in the degradation of the melt, decline in orientation of the macromolecules and a slight fall in the degree of crystallinity and melting point of the fibres. Pigment is also a component which may change the pseudoplasticity of the melt due to the structure resulting from its agglomeration and steric immobilization.

Effect of diphosphonite stabilizer on the properties of polypropylene fibres prepared from fibre wastes

Diphosphonite introduced into fibre wastes from the manufacture of polypropylene fibre has a multifunctional action: it improves pigment dispersion; it raises the light resistance of cord fibre and stability of properties in processing and storage; it improves the service properties of carpet articles: strength, bulk elasticity, and resistance to abrasion.

Effect of stearates and difficultly dispersible pigments on the properties of polypropylene fibres

Effect of stearates and difficultly dispersible pigments on the properties of polypropylene fibres

Effect of drawing on creep fracture of polypropylene fibers

AbstractThe ultimate properties of polypropylene fibers, prepared by drawing the same undrawn fibers to different draw ratios, were determined by the creep fracture method at temperatures from 40 to 120°C. The composite curves of the engineering stress at break, the true stress at break, the ultimate extension ratio were constructed as a function of reduced time to break by assuming time–temperature superposition. The temperature dependence of the shift factor aT used in the superposition could be represented by a single equation of the Williams, Landel, and Ferry form. The composite curves of the true stress at break for the samples with different draw ratios were almost the same independently of draw ratio. The composite curves of the ultimate extension ratio for these samples could be reduced to a single curve by assuming that the ultimate extension ratio evaluated with respect to the unit length of the undrawn fibers were constant independently of draw ratio if the time to break and temperature conditions of the measurement were fixed constant. A possible fracture mechanism is discussed on the basis of the fracture mechanisms proposed by Samuels and Peterlin.

Magnetic study of elongated polypropylene fibres

A study is made of the magnetic properties of polypropylene fibres (PP) subjected to permanent unidirectional deformation at room and higher temperatures of the medium (120°C). It follows from the results that the values of the magnetic susceptibility, measured perpendicular to the axis of the fibres, change as a function of the relative elongation while they express the changes in orientation of the polymer chains of the fibre in the crystallinity and the deformation of the crystal lattice. The magnetic susceptibility first increases with the relative elongation at room temperature; it then passes through a certain maximum and then suddenly drops and again rises. The rise in susceptibility is explained by the gradual increase in orientation of the macromolecules. The sudden drop in susceptibility is connected with the increase in the crystalline ratio in the fibre and with the formation of inter-molecular bonds. Repeated increase in susceptibility occurs as a result of deformation of the crystal lattice and the symmetry of the electron clouds of bonds is therefore disturbed. In the case of deformation at a higher temperature of the medium (120°C) a repeated increase at greater elongation was not observed since the more favourable energy conditions with such elongation prevents the deformation of the crystal lattice. The conclusions reached from measurements of the magnetic susceptibility agree with the interpretation of the results of measuring the density, optical birefringence and the results of X-ray methods.

Effects of Ultraviolet Irradiation on the Properties of Polypropylene Fibers

Effects of Ultraviolet Irradiation on the Properties of Polypropylene Fibers