National Technical Reports Library - NTRL

National Technical Reports Library

The National Technical Information Service acquires, indexes, abstracts, and archives the largest collection of U.S. government-sponsored technical reports in existence. The NTRL offers online, free and open access to these authenticated government technical reports. Technical reports and documents in its repository may be available online for free either from the issuing federal agency, the U.S. Government Publishing Office’s Federal Digital System website, or through search engines.




Details
Actions:
Download PDFDownload XML
Download

Polymer Filler Aging and Failure Studied by Lateral Force Microscopy.


DE2009956856

Publication Date 2009
Personal Author Ratto, T.; Saab, A. P.
Page Count 6
Abstract In the present work, we study, via force microscopy, the basic physical interactions of a single bead of silica filler with a PDMS matrix both before and after exposure to gamma radiation. Our goal was to confirm our results from last year, and to explore force microscopy as a means of obtaining particle-scale polymer/filler interactions suitable for use as empirical inputs to a computational model consisting of an ensemble of silica beads embedded in a PDMS matrix. Through careful calibration of a conventional atomic force microscope, we obtained both normal and lateral force data that was fitted to yield adhesion, surface shear modulus, and friction of a 1 im silica bead in contact with PDMS layers of various thickness. Comparison of these terms before and after gamma exposure indicated that initially, radiation exposure lead to softening of the PDMS, but eventually resulted in stiffening. Simultaneously, adhesion between the polymer and silica decreased. This could indicate a serious failure path for filled PDMS exposed to radiation, whereby stiffening of the bulk polymer leads to loss of compressive elastic behavior, while a decrease in polymer filler adhesion results in an increased likelihood of stress failure under load. In addition to further testing of radiation damaged polymers, we also performed FEA modeling of silica beads in a silicone matrix using the shear modulus and adhesion values isolated from the force microscopy experiments as model inputs. The resulting simulation indicated that as a polymer stiffens due to impinging radiation, it also undergoes weakening of adhesion to the filler. The implication is that radiation induces a compound failure mode in filled polymer systems.
Keywords
  • Polymeric materials
  • Fillers
  • Radiation effects
  • Microscopy
  • Aging tests
  • Adhesion
  • Particles
  • Polymer/filler interactions
Source Agency
  • Technical Information Center Oak Ridge Tennessee
Corporate Authors Lawrence Livermore National Lab., CA.; Department of Energy, Washington, DC.
Supplemental Notes Sponsored by Department of Energy, Washington, DC.
Document Type Technical Report
NTIS Issue Number 200924
Contract Number
  • DE-AC52-07NA27344
Polymer Filler Aging and Failure Studied by Lateral Force Microscopy.
Polymer Filler Aging and Failure Studied by Lateral Force Microscopy.
DE2009956856

  • Polymeric materials
  • Fillers
  • Radiation effects
  • Microscopy
  • Aging tests
  • Adhesion
  • Particles
  • Polymer/filler interactions
  • Technical Information Center Oak Ridge Tennessee
  • DE-AC52-07NA27344
Loading