Side chain liquid crystalline polymers as nonlinear optical materials
AssigneeThe University of Southern Mississippi
InventorAnselm C. Griffin, III
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Abstract
Side chain liquid crystalline polymers which exhibit nonlinear optical responses, particularly second and third harmonic generation, are presented together with methods for making them. These polymers derive their nonlinear optical behavior from selective pendant groups that are attached via spacers to the backbone. Several embodiments having chiral structures are subject to efficient dipolar and molecular alignment by electric field poling. The methods disclosed for making these polymers are polycondensation, graft polymerization, and copolycondensation.
Claims40
A composition of matter, comprising a liquid crystalline, noncentrosymmetric polymer having a polymeric backbone and a plurality of dipolar pendant groups attached at intervals along the backbone;
- said dipolar pendant groups comprising a pi-electron donor and a pi-electron acceptor that comprises NO.sub.2 or CN and is conjugatively connected to the pi-electron donor.
A composition of matter, comprising a liquid crystalline, noncentrosymmetric polymer which includes:
- a polymeric backbone;
- a plurality of first pendant groups attached at intervals along the backbone, wherein said first pendant groups comprise a pi-electron donor and a pi-electron acceptor that comprises NO.sub.2 or CN and is conjugatively connected to the pi-electron donor;
- and
- a plurality of second pendant groups attached at intervals along the backbone, wherein said second pendant groups comprise chiral groups.
A composition of matter, comprising a liquid crystalline polymer that has a polymeric backbone and a plurality of dipolar pendant groups attached at intervals along the backbone;
- wherein said dipolar pendant groups comprise a pi-electron donor and a pi-electron acceptor that is conjugatively connected to the pi-electron donor and comprises NO.sub.2 or CN;
- and wherein said dipolar pendant groups have been electrically poled to provide noncentrosymmetry to said polymer.
A composition of matter, comprising a liquid crystalline, noncentrosymmetric polymer having a polymeric backbone and a plurality of dipolar pendant groups attached at intervals along the backbone;
- wherein said dipolar pendant groups comprise a pi-electron donor and a pi-electron acceptor that is conjugatively connected to the pi-electron donor and comprises NO.sub.2 or CN;
- and wherein said polymer additionally comprises chiral groups.
A liquid crystalline polymer which comprises:
- a polymeric backbone;
- a plurality of dipolar pendant groups spaced along and attached to the backbone wherein said pendant groups include a pi-electron donor and a pi-electron acceptor which is conjugatively connected to the pi-electron donor and wherein said pi-electron acceptor comprises NO.sub.2 or CN;
- and
- wherein said polymer has sufficient dipolar orientation or chirality to render the polymer noncentrosymmetric.
A noncentrosymmetric polymer comprising the following structure:
- ##STR16## wherein X.sub.1 is a pi-electron donor;
- Z.sub.1 is NO.sub.2 or CN;
- Y is a linking group capable of transmitting pi-electron density from X.sub.1 to Z.sub.1 ;
- W is CH or N;
- X.sub.2 or H;
- Z.sub.2 is NO.sub.2 or H;
- m and n are integers of at least 2;
- and R is the repeating unit of the polymer backbone.
A polymer comprising:
- ##STR19## wherein m and n are integers;
- Z is 1,4-butylene or 1-methyl-1,3-propylene or 3-methyl-1,6-hexylene;
- and Y is CH or N.
Dependencies are inferred from the claim text.