Controllable construction of cross‐linking network for regulating on the mechanical properties of polydimethylsiloxane and polydimethylsiloxane/carbon nanotubes composites

Abstract

Herein, the cross‐linking density was adjusted controllably by tuning the curing reaction to gain polydimethylsiloxane (PDMS) elastomers with different mechanical performances. First of all, the cross‐linking network of PDMS was adjusted by tuning the parameters of the fabrication process such as curing temperature, curing time, and component ratio. Lowering the temperature, shortening the curing time, and using less curing agent were discovered to effectively reduce the cross‐linking density. Then, the effects of important factors on cross‐linking density, including the fabrication process, the time for post‐curing, and the content of carbon nanotube (CNT), were thoroughly discussed. Furthermore, the dynamic mechanical performance, mechanical characteristics, and viscoelastic properties of PDMS and PDMS/CNT composites were studied based on the regulation of the cross‐linking network. The stronger the cross‐linking density, the higher the storage modulus, the greater the restriction on the molecular chain of silicone rubber. Besides, the post‐curing for 5 months and the introduction of CNT fillers appeared to be a viable option for promoting the cross‐linking reaction with higher density and thereby strengthening the mechanical properties of PDMS.

Molecular Origins of Shock Dissipation in Polymer-Based Nanocomposites

“…Due to the thermal stability of the PEEK system, the interfacial and interchain shock dissipation energy rise concurrently, maintaining a stable ratio. However, numerous cross-links are formed in PDMS at high temperatures, restricting the motion between some molecular chains, , causing the rate of increase in interchain shock dissipation energy to be lower than that of interfacial rate at high temperatures, increasing the interfacial ratio. Overall, these statistical results are consistent, showing friction between polymer chains as the primary damping mechanism in polymer nanocomposites, while interfacial friction plays a secondary role. , …”

Tripartite Cationic Interpenetrating Polymer Network Anion Exchange Membranes for Fuel Cells

“…It can be seen from Table S3 that CQV 50% exhibits great brittleness and hardness, and the as-prepared QPSVBC membrane is basically unable to bend. The brittleness and hardness decrease significantly with the increase of PQ 10 content in the membrane, which is manifested by a decrease in the tensile strength and Young’s modulus, also a rapid increase in the elongation at break . Arbitrary deformation such as folding and bending can be realized when the PQ 10 content in the membrane exceeds 1/5.…”

“…The brittleness and hardness decrease significantly with the increase of PQ 10 content in the membrane, which is manifested by a decrease in the tensile strength and Young's modulus, also a rapid increase in the elongation at break. 39 Arbitrary deformation such as folding and bending can be realized when the PQ 10 content in the membrane exceeds 1/ 5. As a result, QVP 50%-2 exhibits excellent strength and toughness, with a tensile strength of 13.72 MPa and an elongation at break of 38.59%.…”

Electrical properties of elastomer‐based composites reinforced with carbon nanotubes—A review

“…This value is significantly lower than the values reported for PDMS/CNT nanocomposites in Table 1. 97,98 In the study conducted by Cai et al, 176 the cross-linking density of polydimethylsiloxane (PDMS) was adjusted through precise control of the curing reaction. The dynamic mechanical performance, mechanical characteristics, and viscoelastic properties of both PDMS and PDMS/CNT composites were thoroughly investigated, focusing on the modulation of the cross-linking network.…”