ISSN:
1435-1536
Keywords:
Rubber elasticity
;
end-linked poly(dimethylsiloxane) networks
;
polydispersity
;
clustering of crosslinks
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract End-linked poly(dimethylsiloxane) (PDMS) networks with different molecular weight distributions (MWD) of the primary chains were prepared and investigated by isothermal stress-strain measurements. We found a lowering of the elastic modulus with increasing broadness of the MWD. The observed range of the moduli seems not to be restricted to the region limited by the classical models of rubber elasticity. This result is based on our own experimental investigations and on a reanalysis of data taken from the literature. In the case of nearly monodisperse distributions (M n /M w ≲1) the effect of configurational restrictions of the network strands probably dominates. In the opposite case (M n /M w ≪1), we discuss that spatial clustering of the crosslinks may reduce the effective number of elastically active network junctions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00657430
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