Accession Number : ADA255359


Title :   The Role of Entanglements in the Swelling of Poly(dimethylsiloxane) Networks


Descriptive Note : Final rept.,


Corporate Author : TOTAL ARMY PERSONNEL COMMAND ALEXANDRIA VA


Personal Author(s) : Malone, Shawn P


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a255359.pdf


Report Date : Aug 1992


Pagination or Media Count : 122


Abstract : The swelling of model and imperfect polydimethylsiloxane (PDMS) networks in solvents and polymer chains were studied to see how the role of entanglements affects the predictions of the Flory-Rehner swelling model. The model networks were prepared by end-linking difunctional PDMS (B2) with a given amount of tetrafunctional crosslinker (A4) to obtain networks with a minimum amount of elastically ineffective chains. The imperfect networks were prepared by end-linking mixtures of monofunctional PDMS (B1), B2, and A4 to obtain networks containing pendant chains and branched structures. The equilibrium elastic moduli, Ge, of the networks were determined from dynamic mechanical experiments and were found to be greater than the values predicted from the affine and phantom network theories when using a branching model of nonlinear polymerization (Macosko-Miller model) to characterize the networks.


Descriptors :   *SILOXANES , *POLYMERS , *NETWORKS , *METHYL RADICALS , PENTANES , THESES , CROSSLINKING(CHEMISTRY) , CHAINS , SOLVENTS , CHEMICAL EQUILIBRIUM , PRECURSORS , PARAMETERS , SYNTHESIS , INTERACTIONS , MODULUS OF ELASTICITY


Subject Categories : Physical Chemistry
      Polymer Chemistry
      Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE