Accession Number:

ADA295717

Title:

Exploring Factors that Determine Cis/Trans Structure and Tacticity in Polymers Prepared by Ring Opening Metathesis Polymerizations Involving Initiators of the Type Syn and Anti Mo(NAr)(CHCMe2Ph)(OR)2. Observation of a Temperature Dependent Cis/Trans Ratio.

Descriptive Note:

Tecnical rept.,

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF CHEMISTRY

Personal Author(s):

• Schrock, Richard R.
• Lee, Jin-Kyu
• O'Dell, Richard
• Oskam, John H.

Report Date:

1995-06-14

Pagination or Media Count:

30.0

Abstract:

The factors that determine the structure cistrans and tacticity of polymers prepared by ring opening metathesis polymerization ROMP Using well-defined initiators of the type MoNArylCHCMe2PhOR2 Aryl a substituted aryl group and OR a variety of alkoxides have been explored. The main finding is a dependence of cistrans structure on temperature at low temperatures -35 deg C all cis polymer is formed and at high temperatures 65 deg C up to 90 trans polymers are formed. These results are consistent with formation of cis polymer from syn alkylidene rotamers and trans polymer from anti alkylidene rotamers in circumstances where syn and anti rotamers can interconvert. jg

Descriptors:

• *POLYMERS
• LOW TEMPERATURE
• OPENING(PROCESS)
• METHYL RADICALS
• HIGH TEMPERATURE
• POLYMERIZATION
• MOLYBDENUM
• HYDROGEN
• CHEMICAL REACTIONS
• SYMMETRY
• ARYL RADICALS
• MOLECULAR STRUCTURE
• SUBSTITUTES
• RINGS
• PHENYL RADICALS
• HYDROXYL RADICALS
• ALCOHOLS
• ALKALI METALS
• ALKOXY RADICALS

Subject Categories:

• Polymer Chemistry
• Inorganic Chemistry
• Organic Chemistry
• Physical Chemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE