3m Innovative Properties Company

Mark McCormick

Nathan E Schultz

Fuming B Li

Kelly A Volp

Jinsheng Zhou

Kuan-Yin Lin

James C DeLozier

Aurore Y J Mercelat

William J Schultz

Peter D Condo

Wendy L Thompson

Ilya Gorodisher

Chad A Haraldson

Mary I Buckett

Douglas P Goetz

Robert J Webb

Gregory P Sorenson

Steven John Pachuta

Katri M Huikko

Hollow fiber membranes, membrane contactors, and related production and use methods. The membranes include a substrate having a multiplicity of pores and a skin layer overlaying the porous substrate. The porous substrate includes a first semi-crystalline thermoplastic polyolefin (co)polymer resin and a nucleating agent in an amount effective to achieve nucleation. The skin layer includes a second semi-crystalline thermoplastic polyolefin (co)polymer resin derived by polymerizing at most 98 wt. % of 4-methyl-1-pentene monomer with at least 2 wt. % of linear or branched alpha olefin monomers. Preferably, the first thermoplastic polyolefin (co)polymer is different from the second thermoplastic polyolefin (co)polymer. The skin layer is less porous than the porous substrate and forms an outer surface of the hollow fiber with the porous substrate forming an inner surface. The hollow fibers are formed by co-extruding the porous substrate resin and the skin layer resin through an annular die.

Hollow fiber membranes with nucleating agent and methods of making and using the same

Asymmetric hollow fiber membranes, membrane contactors, and related production and use methods. The asymmetric hollow fiber membranes include a porous substrate having a multiplicity of pores, the porous substrate including at least a first semi-crystalline thermoplastic polyolefin copolymer derived by polymerizing at most 3 wt. % of linear or branched alpha olefin monomers with at least 97 wt. % of 4-methyl-1-pentene monomer. The asymmetric hollow fiber membranes also include a skin layer overlaying the porous substrate, the skin layer including a second semi-crystalline thermoplastic polyolefin copolymer derived by polymerizing at least 2 wt. % of linear or branched alpha olefin monomers with at most 98 wt. % of 4-methyl-1-pentene monomer. The skin layer is less porous than the porous substrate and forms an outer surface of the asymmetric hollow fiber membrane, while the porous substrate forms an inner surface of the hollow fiber membrane. The skin layer is preferably nonporous.

Asymmetric hollow fiber membranes and methods of making and using the same

A class of antioxidant compositions include benzotriazole phenolate salts with substituents either ortho to the phenol hydroxide group and/or para to the phenol hydroxide group can be prepared from substituted benzotriazole phenols. The ortho substituent group can be a simple hydrocarbon, alkoxy or amino group, or the ortho substituent group can be a linking group, linking the benzotriazole phenolate to another benzotriazole phenolate group.

Substituted benzotriazole phenolate salts and antioxidant compositions formed therefrom

Polymeric compositions include at least one polymer that is free of ester linkages and an additive that is a benzotriazole phenolate salt with substituents either ortho to the phenol hydroxide group and/or para to the phenol hydroxide group. The substituted benzotriazole phenolate salts can be prepared from substituted benzotriazole phenols. The ortho substituent group can be a simple hydrocarbon, alkoxy, or amino group, or the ortho substituent group can be a linking group, linking the benzotriazole phenolate to another benzotriazole phenolate group.

Polymeric matrices with ionic additives

Compositions comprising surface-modified calcite nanoparticles dispersed in a curable resin and to coatings and fibrous composites incorporating such compositions are described. The nanocalcite particles have a high magnesium to calcium surface concentration ratio. The surface-modifying agents include a binding group ionically associated with the nanoparticles, and a compatiblizing segment compatible with the curable resin. The surface-modifying agent may also include a reactive group capable of reacting with the curable resin. Methods of preparing nanocalcite composites, and coatings and fibrous composites prepared from such nanocalcite composites are also described.

High magnesium surface concentration nanocalcite composites

A curable benzoxazine composition is described wherein the benzoxazine is derived from an aryl amine having a b.p.&#x3e;200&#xb0; C. The curable compositions are more thermally stable and have reduced weight loss and by-products upon cure.

Curable benzoxazine compositions with improved thermal stability

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Saint Paul, MN, United States of America

Mark McCormick