Revision as of 22:17, 24 September 2020 edit 76.178.20.254 (talk) The textbook (2nd. edition) states that the material is strained and the stress is measured and lags behind. From basic theory this is what the equations show. ← Previous edit		Revision as of 14:10, 20 October 2020 edit undo Dadasacks (talk \| contribs) 303 edits m →Polymer composition: As spelled in EPDM_rubber Next edit →
Line 71: ===Polymer composition=== Varying the composition of monomers and [[cross-link]]ing can add or change the functionality of a polymer that can alter the results obtained from DMA. An example of such changes can be seen by blending ethylene- propylene- diene monomer (EPDM) with [[styrene-butadiene rubber]] (SBR) and different cross-linking or curing systems. Nair ''et al.'' abbreviate blends as E<sub>0</sub>S, E<sub>20</sub>S, etc., where E<sub>0</sub>S equals the weight percent of EPDM in the blend and S denotes sulfur as the curing agent.<ref name="Nair">{{cite journal\|last=Nair\|first=T.M.\|author2=Kumaran, M.G. \|author3=Unnikrishnan, G. \|author4= Pillai, V.B. \|year=2009\|title=Dynamic Mechanical Analysis of Ethylene-Propylene-Diene Monomer Rubber and Styrene-Butadiene Rubber Blends\|journal=Journal of Applied Polymer Science\|volume=112\|pages=72–81\|doi = 10.1002/app.29367}}</ref> Increasing the amount of SBR in the blend decreased the storage modulus due to [[intermolecular]] and [[Intramolecular force\|intramolecular]] interactions that can alter the physical state of the polymer. Within the glassy region, EPDM shows the highest storage modulus due to stronger intermolecular interactions (SBR has more [[steric]] hindrance that makes it less crystalline). In the rubbery region, SBR shows the highest storage modulus resulting from its ability to resist intermolecular slippage.<ref name="Nair" />

Dynamic mechanical analysis: Difference between revisions