Accession Number:

ADA456611

Title:

Reactivity Ratios of Cyclohexyl Polyhedral Oligomeric Silsesquioxane (POSS)-Styrene with Styrene Monomer

Descriptive Note:

Conference paper

Corporate Author:

AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE

Report Date:

2006-05-01

Pagination or Media Count:

3.0

Abstract:

Polyhedral Oligomeric Silsesquioxanes POSS are nanoparticles that are used to enhance the thermal and mechanical properties of many polymeric systems. Starting in 1993, there has been extensive research in understanding how POSS affects these properties. Certain POSS macromers can be copolymerized with organic monomers to form nanocomposite type materials. A model is emerging for how addition-polymerized POSS copolymers can undergo a type of self-assembly to form a nanocomposite. The R-group on the POSS moiety plays a critical role in determining the properties of the nanocomposite, as it determines the level of compatibility of the POSS with the comonomer and how strongly the POSS cages associate. A common but not always observed phenomenon with POSS in glassy polymers, is that cyclohexyl POSS often increases thermal transitions while isobutyl POSS frequently plasticizes. It is possible that this is due to the length scale of the POSS-cage domains andor their level of compatibility with the polymer matrix.

Subject Categories:

  • Polymer Chemistry
  • Laminates and Composite Materials

Distribution Statement:

APPROVED FOR PUBLIC RELEASE