Exploring the contributions of variable network structure on rubber elasticity using model silicone elastomers
Poly dimethyl siloxane (PDMS) is a highly flexible inorganic polymer currently widely used in soft lithography and microfluidics applications due to its optical transparency,biocompatibility,and gas permeability in addition to the simplicity in fabrication process and ease of controlling the mechanical properties.Recent work has explored phenomenological and structure based entanglement models for a better understanding of entropic mechanisms in elastomers and to address limitations in classical rubber elasticity theory vis-à-vis the topological interaction arising due to chain crossing and their finite extensibility.To quantify the individual effects of physical entanglements and chemical crosslinking on the network structure-property relationships,we prepared two differently crosslinked PDMS elastomers and used swelling of the polymer in xylene to obtain variable microstructures.Highly crosslinked PDMS networks show isotropic swelling in xylene and high values of storage modulus as compared to PDMS obtained using low amounts of crosslinker.Uniaxial tension and biaxial experiments show that an increase in crosslinker leads to a higher modulus of the elastomers.Biaxial mechanical experiments show that the slip link model best fits our experimental data obtained using equibiaxial and nonequibiaxial tests that add constraints to the chain deformations.Dynamic mechanical analysis (DMA) studies show the dynamic variations in the chemical crosslinks and physical entanglements on the properties of the elastomer networks.Such studies relate structure-property relationships in PDMS networks that may be useful in microfluidics,mechanobiology studies to assess effects of substrate stiffness on cellular responses and biosensor applications.
Polydimethysiloxane Swelling Entanglement Crosslinking
Anju R.Babu Namrata Gundiah
Centre for Nano Science and Engineering Centre for Nano Science and Engineering;Department of Mechanical Engineering
国际会议
北京
英文
1-9
2013-06-16（万方平台首次上网日期，不代表论文的发表时间）