University of Dayton

Richard P Chartoff

John M Butler

James A Harvey

Tat Hung Tong

John Weber Schultz

Jayprakash C Bhatt

Jill S Ullett

A method and apparatus for producing ordered parts by from non-ordered liquid crystal monomers. Liquid crystal monomers contain stiff, rod-like mesogenic segments which can be aligned by an external force such as shear, electric field or magnetic field, causing an anisotropy in properties. When cured in the aligned stated by photopolymerizing the aligned monomers the anisotropic structure is &ldquo;locked in&rdquo; resulting in materials with anisotropic physical and mechanical properties. The rigid structure of the mesogenic segments can result in cured networks with high glass transition temperatures if the spacer groups which connect the mesogenic core with the reactive end groups are kept short. Glass transition temperatures of postcured parts ranged from 75 to 148&deg; C. depending on resin and processing conditions. A mechanical anisotropy on the order of two was measured for aligned samples.

Methods and apparatus for producing ordered parts from liquid crystal monomers

Rigid-rod monomers and polymers are provided for use in applications such as rapid prototyping, composites and adhesives. The monomers can be photocured through the end groups and then thermally post cured through the acetylene groups. The result is a highly crosslinked polymer having an effective glass transition temperature well above 200&deg; C.

Rigid rod monomers and polymers for use in rapid prototyping, composites, and adhesives

Diacrylate monomers and polymers formed therefrom

A method and apparatus for producing ordered parts by stereolithography from non-ordered liquid crystal monomers. Liquid crystal monomers contain stiff, rod-like mesogenic segments which can be aligned by an external force such as shear, electric field or magnetic field, causing an anisotropy in properties. When cured in the aligned stated by photopolymerizing the aligned monomers the anisotropic structure is 'locked in' resulting in materials with anisotropic physical and mechanical properties. The rigid structure of the mesogenic segments can result in cured networks with high glass transition temperatures if the spacer groups which connect the mesogenic core with the reactive end groups are kept short. Glass transition temperatures of postcured parts ranged from 75 to 148.degree. C. depending on resin and processing conditions. A mechanical anisotropy on the order of two was measured for aligned samples.

Method and apparatus for stereolithography

The present invention provides an epoxy resin of the formula ##STR1## where A is selected from the group consisting of --C(CH.sub.3).sub.2 --, --C(CF.sub.3).sub.2 --, --S--, --SO.sub.2 --, --CH.sub.2 --, --CO--, --O--, and --C.sub.3 H.sub.6 --, and each B.sub.1, B.sub.2, B.sub.3, and B.sub.4 is independently selected from the group consisting of --H, --F, --Cl, --Br, --I, --CH.sub.2 CH.dbd.CH.sub.2, --CH.sub.3, --C.sub.2 H.sub.5, --C.sub.3 H.sub.7, and --C.sub.4 H.sub.9. The present invention also provides a curable composition comprising an epoxy resin of the foregoing formula (I) and an effective curing amount of a hardener for an epoxy resin. The moisture sensitivity of the cured castings and/or composites based on the epoxy resins is lower than known epoxy resin castings and/or composites that have comparable thermal stability, modulus, strength, processability, and toughness.

Epoxy resin

The present invention provides a process for producing aromatic ether bismaleimides of the Formula (II) ##STR1## wherein A is a divalent mononuclear or polynuclear aromatic linking group. The process provides good yields and can be scaled up readily to commerical size runs. The present invention also provides compositions containing at least about 80 weight % of the bismaleimide of Formula (II) above.

Process for the preparation of aromatic ether bismaleimides

The present invention provides a process for producing aromatic ether bismaleimides of the Formula (II) ##STR1## wherein A is a divalent mononuclear or polynuclear aromatic linking group. The process provides good yields and can be scaled up readily to commercial size runs. The present invention also provides compositions containing at least about 80 weight % of the bismaleimide of Formula (II) above.

Growing community of inventors

Cincinnati, OH, United States of America

Richard P Chartoff