A polyolefin porous separator includes a first surface and a second surface corresponding to the first surface. The surfaces of the polyolefin porous separator contain dendritic crystals and micropores, the dendritic crystals intersect with the micropores on the first surface or/and the second surface, and the dendritic crystals penetrate through the second surface from the first surface. A preparation method of the polyolefin porous separator includes: (1) a mixed melting of polyethylene resin and a mineral oil; (2) an extrusion of the mineral oil/polyethylene resin molten mixture; (3) a stretching of a thick sheet in a machine direction (MD); (4) a stretching of the separator in a transverse direction (TD); (5) immersing the separator into a solvent to extract the mineral oil; (6) a secondary stretching of the separator in the TD; and (7) subjecting the separator having the longitudinal crystals to a heat-setting treatment and then rolling up.

A material with significant protection properties from galactic cosmic radiation and solar energetic particles. Hydrogen-rich benzoxazines which are particularly effective for shielding against such radiation. Benzoxazine resin meets the processing requirements for use with ultra-high molecular weight polyethylene fiber as a hydrogen-rich reinforcement: cure of the resin at 120° C. This highly reactive benzoxazine resin also exhibits low viscosity and adequate shelf life.

The present invention generally provides implantable articles and methods of forming implantable articles from a crosslinked ultrahigh molecular weight polyethylene (“UHMWPE”) blend stabilized with Vitamin E. The crosslinked UHMWPE blend may be prepared by combining the UHMWPE material and vitamin E prior to irradiating the UHMWPE blend with electron beam radiation at a sufficient radiation dose rate to induce crosslinking. The crosslinked UHMWPE blend may be incorporated into a variety of implants, and in particular, into endoprosthetic joint replacements.

The present invention generally provides implantable articles and methods of forming implantable articles from a crosslinked ultrahigh molecular weight polyethylene (“UHMWPE”) blend stabilized with Vitamin E. The crosslinked UHMWPE blend may be prepared by combining the UHMWPE material and vitamin E prior to irradiating the UHMWPE blend with electron beam radiation at a sufficient radiation dose rate to induce crosslinking. The crosslinked UHMWPE blend may be incorporated into a variety of implants, and in particular, into endoprosthetic joint replacements.

Disclosed herein is a porous hybrid elastomer/polyolefin film, which is a porous polyolefin film wherein at one or more isolated areas of the film pores are at least partly filled with an elastomer. This hybrid film shows improved resistance to tearing, whereas other properties like porosity, polarity, thickness, flexibility, and non-stickiness of the film are substantially retained. Other advantages include improved suture retention. The invention also provides a method to increase tear resistance of a porous polyolefin film comprising steps of providing a porous polyolefin film; identifying one or more locations on the film, at which locations tearing is likely to occur during intended use of the film; applying at the identified locations of the film an amount of a solution of an elastomer in solvent; and substantially removing the solvent; to result in a hybrid elastomer/polyolefin film having one or more isolated areas where pores in the film are at least partly filled with the elastomer. Further aspects concern uses of these hybrid films as a component of a medical implant or device, especially for use in contact with body tissue or fluids, such as in vascular applications like a vascular graft, a stent cover or a catheter balloon; and medical devices or implants comprising said porous hybrid films.

The invention discloses a separator with a wide temperature range and a low heat shrinkage and a method for preparing the same. The invention belongs to the field of electrochemistry. The separator of the invention includes: an irradiation crosslinked fluoropolymer A with a melting point above 150° C. and/or a polymer B containing a benzene ring in its main chain; an ultrahigh molecular weight polyethylene having a molecular weight of 1.0×10.sup.6-10.0×10.sup.6, and a high density polyethylene having a density in the range of 0.940-0.976 g/cm.sup.3; the temperature difference between pore closing temperature and film breaking temperature of the separator is 80-90° C., preferably 85-90° C., the heat shrinkage of the separator is 2.0% or less. The separator of the invention has a high temperature difference between film breaking temperature and pore closing temperature, and a low heat shrinkage; when the separator of the invention is used in an electrochemical device, the reliability and safety of electrochemical device can be effectively improved.

Disclosed in present invention are a high-wettability separator and a preparation method therefor. The separator comprises an ethylene copolymer, a grafting polyolefin, an ultrahigh molecular weight polyethylene having a molecular weight ranging from 1.0×10.sup.6 to 10.0×10.sup.6, and a high-density polyethylene having a density ranging from 0.940 g/cm.sup.3 to 0.976 g/cm.sup.3, the content of the ethylene copolymer is 1-5 parts by weight, and the content of the grafting polyolefin is 0-5 parts by weight, on the basis that the total weight of the ultrahigh molecular weight polyethylene and the high-density polyethylene is 100 parts. The separator has a contact angle with lithium ion battery electrolyte of 20° to 40°.

A polymer composition for producing gel extruded articles is described. The polymer composition contains polyethylene particles combined with a plasticizer. The polyethylene particles are particularly selected so that the particles rapidly form a homogeneous gel-like material when combined with the plasticizer during gel processing. In one embodiment, the polyethylene used to produce the particles has a relatively low bulk density. Alternatively or in addition, the particles can have a carefully controlled particle size distribution. Polymer articles such as fibers and films can be produced having little to no imperfections.

An anatomically fitted talar component for use in an ankle replacement system having a body including a talar surface having a portion contoured to approximately or exactly fit with a surface portion of a three dimensional rendering of bone of a talar dome; and a tibial surface configured for forming a joint with a second component of the ankle replacement system. A method of forming the talar component by: (i) obtaining image data of the talar dome, (ii) using the data to create a three-dimensional model of the talar dome, and (iii) forming a body having a talar surface that approximately or exactly fits with a portion of the surface of the three-dimensional model.

The present invention relates to a multimodal polyethylene composition comprising: (A) 40 to 65 parts by weight, preferably 43 to 52 parts by weight, most preferred 44 to 50 parts by weight, of the low molecular weight polyethylene, the low molecular weight polyethylene having a weight average molecular weight (Mw) of 20,000 to 90,000 g/mol and having a MFRa from 500 to 1.000 g/10 min according to ASTM D 1238; (B) 8 to 20 parts by weight, preferably 10 to 18 parts by weight, most preferred 10 to 15 parts by weight, of the first high molecular weight polyethylene having a weight average molecular weight (Mw) of more than 150,000 to 1,000,000 g/mol or the first ultra high molecular weight polyethylene having a weight average molecular weight (Mw) of more than 1,000,000 to 5,000,000 g/mol; and (C) 30 to 50 parts by weight, preferably 37 to 47 parts by weight, most preferred 39 to 45 parts by weight, of the second high molecular weight polyethylene having a weight average molecular weight (Mw) of more than 150,000 to 1,000,000 g/mol or the second ultra high molecular weight polyethylene having a weight average molecular weight (Mw) of more than 1,000,000 to 5,000,000 g/mol, wherein the density of the first high molecular weight polyethylene or the first ultra high molecular weight polyethylene and the second high molecular weight polyethylene or the second ultra high molecular weight polyethylene are in the range from 0.920 to 0.950 g/cm3, and wherein the molecular weight distribution of the multimodal polyethylene composition is from 20 to 28, preferably from 24 to 28, measured by gel permeation chromatography, and a film comprising the multimodal polyethylene composition and the use thereof.