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

• Published in: Journal of applied polymer science Vol. 139; no. 19
• Main Authors: Cai, Jie‐Hua, Huang, Ming‐Lu, Chen, Xu‐Dong, Wang, Ming
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 15-05-2022; Wiley Subscription Services, Inc
• Subjects: Carbon nanotubes; Composite materials; cross‐linking; Curing; Curing agents; Density; Elastomers; Materials science; Mechanical properties; Molecular chains; Polydimethylsiloxane; Polymers; Process parameters; rubber; Silicone resins; Silicone rubber; Storage modulus; Tuning
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.52113

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.
Cross‐linking density was adjusted controllably by tuning the curing conditions, post‐curing and the addition of CNT fillers.