Accession Number : AD0704907

Title :   THERMAL STABILITY OF THE CARBON-CARBON CROSSLINKAGE IN POLYMER NETWORKS.

Descriptive Note : Technical rept.,

Corporate Author : PRINCETON UNIV N J FRICK CHEMICAL LAB

Personal Author(s) : Shaw,Montgomery T. ; Tobolsky,Arthur V.

Report Date : APR 1970

Pagination or Media Count : 23

Abstract : The thermal stability of carbon-carbon crosslinkages in elastomeric systems was studied by comparing the vacuum chemical stress relaxation of samples with different concentrations of these crosslinkages. The systems studied included silicone rubber, crosslinked polyethylenes and Dexsil-201 rubber. Arrhenius activation energies of about 55 kcal/mole were found for the scission of these crosslinkages in the temperature range 300-350C. Crosslinkages added to a sample by additional curing were found to be, in general, more stable than those first formed. A more detailed analysis of the cleavage reaction was performed on peroxide cured Dexsil-201 elastomer - made possible because the main chains of this material are stable at the temperatures used. Two species of crosslinks were distinguishable: one having the same stability as the carbon-carbon crosslinkage in silicone rubber, another being ten times as stable and probably devoid of normal carbon-carbon bonds. (Author)

Descriptors :   (*CROSSLINKING(CHEMISTRY), THERMAL STABILITY), (*INORGANIC POLYMERS, THERMAL STABILITY), (*POLYETHYLENE PLASTICS, CROSSLINKING(CHEMISTRY)), SILOXANES, ELASTOMERS, HEAT OF ACTIVATION, THERMAL STABILITY, BORON COMPOUNDS, PEROXIDES, CURING AGENTS

Subject Categories : Physical Chemistry
      Polymer Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE