Organic polymers with near-zero uniaxial thermal expansion coefficients
US3994867A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1974 |
| Grant date | Nov 30, 1976 |
| Priority date | — |
| Expiry date | Dec 30, 1994 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/3154
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
There are provided processes and compositions for obtaining organic polymeric materials having near-zero uniaxial thermal expansion coefficients. According to one embodiment, an organic polymer having a negative uniaxial thermal expansion coefficient is treated by thermal processing under conditions sufficient to cause at least a portion of the polymer chains to become misaligned, thereby decreasing the magnitude of this thermal expansion coefficient to nearly zero. According to a second embodiment, one or more organic polymers having a negative uniaxial thermal expansion coefficient are combined with one or more materials having a positive thermal expansion coefficient to yield a composite material having a uniaxial thermal expansion coefficient which is nearly zero. Useful in the practice of the invention are polyacetylenes having a negative macroscopic thermal expansion coefficient, which are obtained by the solid-state polymerization of crystalline monomers containing two or more conjugated acetylene groups.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.