Abstract:
The invention relates to a process for preparing a composition comprising 10 to 45% of the total solids weight lignin, polyacrylonitrile or a polyacrylonitrile copolymer, and a solvent to form a lignin-based polyacrylonitrile-containing dope and the resulting products. The dope can be processed to produce fibers, including precursor, oxidized and carbonized fibers. The oxidized fibers are of value for their flame resistant properties and carbonized fibers are suitable for use in applications requiring high strength fibers, or to be used to form composite materials.
Abstract:
Die Erfindung betrifft ein Verfahren zur Herstellung von thermisch stabilisierten schmelzgesponnenen Fasern, bei dem durch Schmelzspinnen hergestellte Polyacrylnitril (PAN)-Fasern bzw. PAN-Faserprecursoren in einer wässrigen alkalischen, zusätzlich ein Lösungsmittel für PAN enthaltenden Lösung behandelt werden. Ebenso betrifft die Erfindung Fasern, die gemäß diesem Verfahren herstellbar sind.
Abstract:
A process is described for producing surface-modified polypropylene filament yarns that are dyeable from aqueous liquors. This process is characterized in that the filament yarns, comprising standard commercial PP, in the course of their formation in a melt spinning procedure, undergo treatment with a hydrogen peroxide solution. The invention further relates to polyolefin filament yarns obtainable by this process, and to the use of these polyolefin filament yarns for producing sheetlike textile structures, with the possibility of advantageous subsequent dyeing with vat dyes. The treatment referred to or the upgrading step, which in accordance with the prior art normally takes place at a much later point in the production chain, therefore yields a hydrophilized filament yarn without an additional downstream treatment step, such as by plasma treatment, for example, and also without any other additional energy input. The resulting filament yarn can be processed and upgraded in the same way as has hitherto been the case in the industrial practice. Without the aftertreatment of the prior art, the textiles obtained in accordance with the invention exhibit a desirable dyeability. This can be achieved without further pretreatment, by means of vat dyeing by the Thermosol process in deep shades, and the vat dyeing at the same time possesses the high light fastness known for vat dyeings.
Abstract:
A high flux and low pressure drop microfiltration (MF) membrane and a method for making the MF membrane. The microfiltration membranes are formed by a method that includes: preparing a nanofibrous structure; and modifying the surface of the nanofibrous structure with a surface modifier. The nanofibrous structure includes an electrospun nanofibrous scaffold or a polysaccharide nanofiber infused nanoscaffold or mixtures thereof. The electrospun nanofibrous scaffold can include polyacrylonitrile (PAN) or polyethersulfone (PES))/polyethylene terephthalate (PET) or mixtures thereof. The surface modifier includes polyethylenimine (PEI) and polyvinyl amine (Lupamin) cross-linked by ethylene glycol diglycidyl ether (EGdGE)/glycidyltrimethylammonium chloride (GTMAC1) or poly(l-(l- vinylimidazolium)ethyl-3-vinylimdazolium dibromide (VEVIMIBr).
Abstract:
A resilient coform nonwoven web that contains a matrix of meltblown fibers and an absorbent material is provided. The meltblown fibers may constitute from 45 wt% to about 99 wt% of the web and the absorbent material may constitute from about 1 wt% to about 55 wt% of the web. The meltblown fibers may be formed from a thermoplastic composition that contains at least one propylene/a- olefin copolymer having a propylene content of from about 60 mole% to about 99.5 mole% and an a-olefin content of from about 0.5 mole% to about 40 mole%. The copolymer may have a density of from about 0.86 to about 0.90 grams per cubic centimeter and the thermoplastic composition may have a melt flow rate of from about 200 to about 6000 grams per 10 minutes, determined at 230°C in accordance with ASTM Test Method D1238-E. The coform web may be imparted with a three-dimensional texture by, for example, using a three-dimensional forming surface. As one example, the resilient coform web is suitable for use as a component in the absorbent core of a personal care absorbent product.
Abstract:
An article comprising a yarn comprising an elastomeric propylene-based polymer composition; said polymer composition comprising at least one elastomeric propylene-based polymer, wherein said yarn has break elongation of greater than 200%.