Disperse Polypropylene fibers

Contrary to other synthetic fiber materials, polypropylene fibers cannot be colored by contacting them with an aqueous solution or dispersion of organic dyes. Due to its highly apolar nature, polypropylene is not able to interact with conventional dye molecules, so that it cannot take up any dye from the dye bath. 

A.R. Horrocks, B.K. Kandola, G. Smart, S. Zhang, and R. Hull, Polypropylene fibers containing dispersed clays having improved fire performance. Part 1 Effect on nanoclays on processing parameters and fibres properties, J. Appl. Polym. Sci., 2007, 106 1707-1717. 

For disperse dyeable fibers such as polyester or polypropylene. Applied by padding or exhausting in a dyebath. 

Polymeric fibers are popular for reinforcing concrete matrices because of their low density (more number of fibers for a prescribed volume fraction), high tensile strength, ease of dispersion, relative resistance to chemicals, and relatively low cost compared to other kinds of fibers. Polypropylene and polyolefin fibers are typically hydrophobic, resulting in a relatively poor bond with concrete matrices compared to some other types of fibers. Treatment of polypropylene with an aqueous dispersion of colloidal alumina or silica and chlorinated polypropylene enhances the affinity of these fibers toward cement particles. Treatment of polypropylene fibers with a surface-active agent provides better dispersion of the fibers and a stronger bond between cement and fiber. The earlier attempts at surface treatments of polypropylene fibers have had only limited success and have not been commercially attractive. 

A pertinent example of the application of Werner s coordination complexes to the coloring of synthetic fibers is exhibited in the case of polypropylene fibers containing nickel. The minute nickel particles have been evenly dispersed throughout the fiber by a chelate stabilizer/ so that upon dyeing with azo disperse dyes bearing the same o-substituents, as noted above, a fast deep color is formed (4)- This example,... 

In 1970, an acid-dyeable polypropylene fiber was described [158]. It was claimed that this fiber could be dyed like nylon and could produce one-batch union shades in blends with cotton and acrylics. The dye site in this fiber was present as a microfilament dispersed within the polypropylene. These microfibers extended to the surface of the fiber and water was readily absorbed in order that acid dyes could penetrate at a reasonable rate to react with the basic dye sites. Acid-dyeable polypropylene fiber products have been available from Phillips [159] and, from Polyolefin Fibres Engineering (PFE) Ltd. [160]. PFE has also introduced a bicomponent fiber readily dyeable with disperse dyestuffs [161]. 

In situ polymerization to prepare immiscible blends was pioneered by Watkins and McCarthy [108], stimulating other researchers to apply this methodology to prepare novel polymer blends [109-112], fiber-reinforced composite materials[39], and electrically conducting composites [66, 67, 113-116]. Polymer blends produced in this manner include polystyrene/poly(vinyl chloride) [117, 118], polysty-rene/PET [119], nanometer-dispersed polypropylene/polystyrene interpenetrating networks [120], polypropylene/polystyrene [121] and polyethylene/polystyrene [122]. The resultant polymer blend may have a unique morphology compared to the traditionally prepared counterpart (if it is feasible to prepare such a blend via conventional procedures) and therefore demands a thorough investigation. 

The aim of this research was to create novel composites for bulk applications using cellulose as reinforcement. We intented to improve properties of polymer composites reinforced with cellulose by pretreating fibers with maleic anhydride modified polypropylene (MAPP). The effect of hydrolytical treatment of cellulose on the dispersibility of fibers in polymers was also investigated. Novel materials based on bacteria-produced polyesters and cellulose were manufactured and their properties evaluated. 

Moskalyuk OA, Aleshin AN, Tsobkallo ES, Krestinin AV, Yudin VE (2012) Electrical conductivity of polypropylene fibers with dispersed carbon fillers. Phys Solid State 54 (10) 2122... 

For example, disperse dyes give only tings to unmodified polypropylene fibers. Application of disperse dyes of different structures and properties on unmodified PP fibers has been reported [427]. However, in most cases, it was found that the saturation values were very low on unmodified PP. A new... 

Although various methods have been reported by the authors, an example shown in Table 2 will be introduced here. Oleophilic polypropylene fibers (pulp-like) were used as the material to entrap oil. A crosslinked poly-(ethylene oxide) hydrogel was used so that the material could desorb the entrapped oil. This crosslinked gel is insoluble in water, although it disperses into water-containing methanol colloidally. This suspension was deposited onto a sheet. 

For those reasons, different types of eoupling agents (Titanates, Isocyanates, etc) have been proposed [10-12], Among the coupling agents for polymer-natural fibers, a low molecular weight polypropylene (PP), modified with maleic anhydride (Epolene E-43) has improved fiber dispersion, and fiber-matrix interaction, promoting PP-cellulosic fiber compatibility [13-14]. 

The surface energy of fibers is closely related to the hydrophilicity of the fiber [38]. Some investigations are concerned with methods to decrease hydrophilicity. The modification, of wood cellulose fibers with stearic acid [43] hydrophobizes those fibers and improves their dispersion in polypropylene. As can be observed in jute-reinforced unsaturated polyester resin composites, treatment with polyvinylacetate increases the mechanical properties [24] and moisture repellency. 

Earlier we found that the addition of alkyl-modified poly(propylene imine) dendrimers to polypropylene leads to fibers which can be dyed in conventional acid or disperse dyeing processes [3]. The alkyl chains make the additive compatible with the polypropylene matrix, while the polar core of the dendrimer can act as a receptor for the dye molecules. This host-guest behavior is analogous to the principle of the dendritic box as described by Meijer et al. [30] and elaborated by Baars et al. for dye extraction processes [31]. 

To conclude this brief digression into history, we may point out one more important aspect the high efficiency of the combined shear in molding of filled thermoplastics. One of the first works in this field was 31) which described experiments carried out with polypropylene filled with a disperse aggregate calcium carbonate (chalk) and a short-fiber material-asbestos. 

Smart, G., Kandola, B.K., Horrocks, A.R., and Marney, D. 2008. Polypropylene hbers containing dispersed clays having improved fire performance Part II Characterization of fibers and fabrics from PP—nanoclay blends, Polym. Adv. Technol., 19 658-670. 

CINDYE DAC-888 is a butyl benzoate type carrier for the dyeing of polyester, polypropylene, and triacetate fibers and blends containing these fibers. It can be used as a carrier with disperse, cationic, and dyestuffs. 

If the melt viscosities of polypropylene and poly(ethylene terephthalate) polymers are reasonably matched under extrusion conditions, a finely dispersed blend may be produced in fiber form. Orientation of such fibers yields strong filaments in which microfibrils of the two partially crystallized polymers are intertwined and unable to separate. Similar fibers with a sheath of one polymer surrounding a core of the other have no mechanical integrity [27]. 

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