Influence of cross-linker concentration on the cross-linking of PDMS and the network structures formed

Capacitive flexible pressure sensor: microfabrication process and experimental characterization

“…5. During our fabrication process, we have chosen a prepolymer/curing agent ratio of 10/1, since it provides more flexible PDMS films (Esteves et al 2009). The spin time was fixed to 90 s and the spin speed was adjusted according to the wanted thickness.…”

Crosslinked PDMS elastomers and coatings from the thermal curing of vinyl‐functionalized PDMS and a diazide aliphatic crosslinker

“…The swelling ratio and insoluble fraction ( w i ) of samples 6 a–c are in good agreement with the values obtained with PDMS 1 a , and represent highly crosslinked materials. As observed earlier, the values of G e are impacted by the [N 3 ]/[CC] ratio through the difference in crosslinking reaction completion 12, 71. Also, whereas tanδ values are characteristic of a random network for [N 3 ]/[CC] = 0.5, they are comparable to the values obtained for an ideal network by Patel et al, for [N 3 ]/[CC] ratios of 1.0 and 1.5 (i.e., tanδ ∼ 0.002) 72.…”

“…Several one part (curing of chain‐ends or randomly functionalized‐polysiloxane by a low molar mass crosslinker) or two part (curing of chain‐ends or randomly functionalized polysiloxane mixtures having complementary reactive groups) systems have been developed using efficient and easy to process chemical pathways that afford network formation through covalent crosslinking of the polysiloxane chains. Most frequently used curing systems are the Sn‐catalyzed condensation of alkoxysilane‐ or silanol‐functionalized PDMS (sol‐gel chemistry),6–10 and the Pt‐catalyzed hydrosylilation of SiH and vinyl‐functionalized PDMS (frequently designated as Sylgard) 11–14. Whereas widely developed and very effective, these systems contain catalyst residuals that prevent their application in the biomedical field 15, 16.…”

Soft Polydimethylsiloxane Thin Elastomeric Films by In Situ Polymerization to be Used as Dielectricum in Actuators

“…Materials B were submitted to a swelling/extraction procedure in order to determine the amount of non‐bonded species as well as the network density. The cross‐linked PDMS materials were extracted by immersion in toluene for several days at room temperature, whereby the solvent was replaced for fresh one every 24 h. The materials were then let drying to constant mass. They were weighted before ( m 0 ) and after extraction ( m 1 ) and the extractable fraction was calculated according to: …”