Investigation onto the Effect of Surface Etching using Chemical Etchants on the Dye-Ability of UHMWPE Fibre

Ultra high molecular weight fibre cannot be dyed using conventional dyeing techniques as they are extremely hydrophobic and do not possess any polar groups. Wet etching of the surface was used as the pre-treatment process to improve the dyeability of the Ultrahigh Molecular Weight Polyethylene (UHMWPE) knitted fabric using potassium dichromate and sulphuric acid as etchants. The surface modified fabric was dyed at 130°C using High Temperature (HT) dyeing technique with disperse dye and evaluated in terms of Color Strength (K/S), washing fastness, rubbing fastness, and tenacity. It has been observed that wet etching improved the colour strength substantially with an overall good fastness to washing and rubbing but the tenacity decreased with an increase in etching time.

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Electrospinning of Ultrahigh-Molecular-Weight Polyethylene Nanofibers

MRS Proceedings ◽

10.1557/proc-1083-r03-03 ◽

2008 ◽

Vol 1083 ◽

Author(s):

Dmitry M. Rein ◽

Yachin Cohen ◽

Avner Ronen ◽

Eyal Zussman ◽

Kim Shuster

Keyword(s):

Molecular Weight ◽

Dielectric Constant ◽

Elevated Temperature ◽

High Molecular Weight ◽

Ultrahigh Molecular Weight Polyethylene ◽

Ultrahigh Molecular Weight ◽

Electrospinning Method ◽

Surface Modified ◽

First Time ◽

Ultra High Molecular Weight

ABSTRACTThe electrospinning method was employed to fabricate extremely fine nanofibers of ultra-high molecular weight polyethylene (UHMWPE) for the first time, using a mixture of solvents with different dielectric constant and conductivity. A novel experimental device for elevated temperature electrospinning of highly volatile and quickly crystallizing polymer solutions and melts was developed. The possibility to produce the highly oriented nanofibers from ultra-high molecular weight polymers suggests new ways for fabrication of ultra-strong, porous, surface modified fibers and single-component nanocomposite yarn with improved properties.

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Microscopic versus process parameters in heavy-oil upgrading

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010012223x ◽

1992 ◽

Vol 50 (1) ◽

pp. 366-367

Author(s):

V.A. Munoz ◽

R.J. Mikula ◽

C. Payette ◽

W.W. Lam

Keyword(s):

Molecular Weight ◽

Liquid Fuels ◽

Chemical Components ◽

Heavy Oils ◽

Synthetic Fuels ◽

High Hydrogen ◽

Optical Texture ◽

Polar Groups ◽

Anisotropic Character ◽

Planar Molecules

The transformation of high molecular weight components present in heavy oils into useable liquid fuels requires their decomposition by means of a variety of processes. The low molecular weight species produced recombine under controlled conditions to generate synthetic fuels. However, an important fraction undergo further recombination into higher molecular weight components, leading to the formation of coke. The optical texture of the coke can be related to its originating components. Those with high sulfur and oxygen content tend to produce cokes with small optical texture or fine mosaic, whereas compounds with relatively high hydrogen content are likely to produce large optical texture or domains. In addition, the structure of the parent chemical components, planar or nonplanar, determines the isotropic or anisotropic character of the coke. Planar molecules have a tendency to align in an approximately parallel arrangement to initiate the formation of the nematic mesophase leading to the formation of anisotropic coke. Nonplanar highly alkylated compounds and/or those rich in polar groups form isotropic coke. The aliphatic branches produce steric hindrance to alignment, whereas the polar groups participate in cross-linking reactions.

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